Foretravel Motorhome Forums => Foretravel Tech Talk => Topic started by: GleamB on November 19, 2019, 11:30:28 pm
Title: Voltage problem revisited
Post by: GleamB on November 19, 2019, 11:30:28 pm
I'm tired, it's late and I will peruse this tomorrow. When I hooked up my power cord to my 50 amp Progressive Industries ..EMS, it read each leg at 118. This is a brand new service pedestal with no known issues. Went into the coach and NOTHING shows on my display??? I needed to keep batteries charged so I checked the adjacent 30 amp outlets on the same pedestal, put on my pigtail and plugged into it for the night. It lite up the display now showing 113 volts each leg. The POSSIBILITY exists that I miss wired the new plug I put on in Texas How do I proceed testing continuity tomorrow.? Do I test at the transfer switch under the bed? I don' t understand how I get no reading at 50 amp but I do at the 30 amp outlet. BTW...this is a standard house outlet, not the 30 amp we normally see in RV parks. Any ideas? Barry? Thanks
Title: Re: Voltage problem revisited
Post by: Barry & Cindy on November 20, 2019, 12:37:04 am
Glenn, sounds like your EMS is portable, which is fine. I assume coach does the same when plugged in without EMS.
The 50amp plug has two hot prongs, one neutral (center), one ground (round). The 2 hots are powered from separately from the pedestal. The 50 to 30 to 20 amp pigtails take the single hot from the 20 or 30 amp outlet and sends it to both 50 amp hot prongs.
BTW, the household outlet is 20 or 15 amp, not 30 amp.
Seems that if pigtails work, and the pedestal is ok, both should work the same.
One way to test with meter is to partially connect 50 amp male plug so some of the brass prongs show. Put meter on the energized visible prongs. Be careful they are hot. Hot to hot is zero with pigtalis, 240 volts with pedestal. One hot to neutral is always 120 volts. Other hot to neutral is always 120 volts. Neutral to ground is zero volts. Each hot to ground is 120 volts.
BTW, 120 volts means anything between 109 & 129. 240 volts means anything between double the 120 volts. Approximate is ok as long as it is close.
If it works sometime and not others, jiggle plug for loose attached copper connection.
Let us know what you find.
What are you looking at when you say nothing shows on my display, what display.
Barry
Title: Re: Voltage problem revisited
Post by: folivier on November 20, 2019, 06:45:42 am
Your EMS may have a couple minute delay before it lets power into the coach. Make sure you're allowing for this when checking inside for power.
Title: Re: Voltage problem revisited
Post by: Woody & Sitka on November 20, 2019, 08:47:29 am
I think folivier meant ATS. My OEM ATS sometimes takes a couple minutes (seems like a half hour sometimes) to connect with a clunk. The portable EMS PT-50X does several continuity tests and will show voltage, Hz, and amps, and an "E" value. If you don't see "E-0", the EMS will block all power. The EMS also has a time delay if it encountered a temporary voltage issue. That delay is 2 minutes and 16 seconds. So it may take around 5 minutes to get safe power to the coach. Try plugging in 50 amp and wait a few. Just my ez button. Woody.
Title: Re: Voltage problem revisited
Post by: wolfe10 on November 20, 2019, 08:57:07 am
Yes, if you are safe working around 120/240 VAC, open the ATS. If two open the one with generator and shore IN and OUT to main breaker panel (the one to the main breaker box is short and easy to trace).
Check for power IN and OUT
On 50 amp shore power: Black to white= 120 VAC Red to white= 120 VAC Black to green= 120 VAC Red to green= 120 VAC Green to white= 0 VAC Red to black= 240 VAC
On 30 amps-- all the same except red to black= 0 VAC
If you don't get those readings on the IN side, work back toward shore power cord until you find the culprit.
On the shore power cord: Two outer straights= hot Center straight= neutral Center round= ground
Title: Re: Voltage problem revisited
Post by: Roger & Susan in Home2 on November 20, 2019, 09:26:02 am
Sort of a side bar ... Could one take 30 amps from two power posts to a Y connection with a 50 amp connection at the end of the Y? Hot from both 30 amp combined to the 2 50 amp hot blades? Hot from each 30 amp to one or the other 50 am hot blade? Can you buy something like a 2-30 amp to 50 amp pigtail?
Title: Re: Voltage problem revisited
Post by: wolfe10 on November 20, 2019, 09:31:57 am
Sort of a side bar ... Could one take 30 amps from two power posts to a Y connection with a 50 amp connection at the end of the Y? Hot from both 30 amp combined to the 2 50 amp hot blades? Hot from each 30 amp to one or the other 50 am hot blade? Can you buy something like a 2-30 amp to 50 amp pigtail?
Lots of "IFF's" here.
At most that would give you a total of 60 amps vs 100 for 50 amp shore power.
Are both hots on the same "Phase"? If so it would be possible to overload the neutral, as the neutral is only designed to carry the DIFFERENCE between draw on L1 and L2.
And, most shore power pedestals have one 50, one 30 and one 15/20. With code being that the 15/20 be in a GFI which would trip with this adapter.
So, for 90% of RV owners, I would strongly suggest against it.
For those with a strong electrical background/knowledge-- MAYBE.
Title: Re: Voltage problem revisited
Post by: Old Toolmaker on November 20, 2019, 09:46:27 am
Brett Wolfe wrote "Yes, if you are safe working around 120/240 VAC, open the ATS. If two open the one with generator and shore IN and OUT to main breaker panel (the one to the main breaker box is short and easy to trace)."
Safe means proper technique, and it's not that complicated.
Wear rubber soled shoes.
Put an alligator clip on your black or negative test lead.
Put your off hand into your pocket.
Clip the black lead to your common rail.
Probe with your good hand and keep your off hand in your pocket.
Art
Title: Re: Voltage problem revisited
Post by: Pierce & Gaylie Stewart on November 20, 2019, 10:25:31 am
Glenn,
Here is a good site on how to wire your 50 amp RV plug. How To Wire A 50 Amp RV Plug: Here Are 5 Quick And Easy Steps (https://crushtheroad.com/how-to-wire-a-50-amp-rv-plug/) . Nothing like a picture to say a thousand words. Why not ask the RV park for their electrical person to give you a hand?
Pierce
Title: Re: Voltage problem revisited
Post by: GleamB on November 20, 2019, 10:40:24 am
Thanks to all. I plugged in PI EMS and it read all is good...118 each leg and EO. Went inside...display showed nothing. Disconnected EMS and plugged in direct. One leg low the other high... just like what happened in Texas when the round ground broke off the main power line. Looks like I will be rewiring plug. Probably a loose ground. You guys are the best
Title: Re: Voltage problem revisited
Post by: GleamB on November 20, 2019, 10:52:41 am
The wiring looks ok to me I am going to plug it in "open" like this so I can multimeter all connections YES... I will be super careful
Title: Re: Voltage problem revisited
Post by: Pierce & Gaylie Stewart on November 20, 2019, 11:08:53 am
A couple of diagrams:
https://www.youtube.com/watch?v=9hmuUBWKwGo
https://www.youtube.com/watch?v=GoOR2AJGjOI
Title: Re: Voltage problem revisited
Post by: GleamB on November 20, 2019, 12:01:00 pm
No apparent problem at the pole but I read 107 and 139 inside The question is WHY? and where do I look for the problem?
Title: Re: Voltage problem revisited
Post by: craneman on November 20, 2019, 12:13:27 pm
No apparent problem at the pole but I read 107 and 139 inside The question is WHY? and where do I look for the problem?
Don't believe the factory monitor, read voltages at the 2 different outlet circuits.
Title: Re: Voltage problem revisited
Post by: GleamB on November 20, 2019, 12:15:42 pm
Don't believe the factory monitor, read voltages at the 2 different outlet circuits. [/quote]
Outlet circuits? Where do I test them?
Title: Re: Voltage problem revisited
Post by: craneman on November 20, 2019, 12:19:29 pm
Use one of the outlets around the sink area, doesn't matter which one and check one on the opposite side, not knowing your floor plan find one near the front. My monitor gives screwy numbers sometimes and the voltages are ok.
Title: Re: Voltage problem revisited
Post by: turbojack on November 20, 2019, 12:28:03 pm
Problem is on the neutral wire. Problem could be in cord reel if you have one or transfer switch. Are you using your EMS and it is showing good voltage but the coach is not?
Be careful you can smoke all of your electric items on the high voltage side.
Title: Re: Voltage problem revisited
Post by: wolfe10 on November 20, 2019, 12:51:05 pm
Thanks to all. I plugged in PI EMS and it read all is good...118 each leg and EO. Went inside...display showed nothing. Disconnected EMS and plugged in direct. One leg low the other high... just like what happened in Texas when the round ground broke off the main power line. Looks like I will be rewiring plug. Probably a loose ground. You guys are the best
Maybe an illusion, but looks like the black hot is not making a good connection.
Title: Re: Voltage problem revisited
Post by: Woody & Sitka on November 20, 2019, 01:47:13 pm
Agree with Brett...in the picture of your open 50a plug, your black connection looks marginal. Also looks like your green ground wire might have been pressed against the neutral lug when you screwed the case together...sufficiently to possibly make connection ground to neutral...not good. I'd rewire it just in case. Agree too that the Foretravel monitor is not state of the art. It's just plugged into an dual outlet behind the panel. Better than nothing I guess, but the Progressive portable is SOA. Woody.
Title: Re: Voltage problem revisited
Post by: GleamB on November 20, 2019, 01:57:46 pm
PI EMS does show an open ground I will redo plug and try again
Title: Re: Voltage problem revisited
Post by: turbojack on November 20, 2019, 02:16:49 pm
Then the problem is between your power plug and the breaker box in your coach.
Title: Re: Voltage problem revisited
Post by: Michelle on November 20, 2019, 03:51:16 pm
Agree with Brett...in the picture of your open 50a plug, your black connection looks marginal. Also looks like your green ground wire might have been pressed against the neutral lug when you screwed the case together
Also can't see the neutral in the picture provided, but hopefully it looks better than the black connection.
Title: Re: Voltage problem revisited
Post by: GleamB on November 20, 2019, 04:10:59 pm
Everything seems to be okay running through the EMS. I want to thank you all, once again, for taking interest in my problem. I actually used a multimeter on most of the outlets in the coach and all were reading good. I will keep an eye out fo any irregularities.
Title: Re: Voltage problem revisited
Post by: GleamB on November 20, 2019, 05:15:47 pm
Oops Premature. All is okay.........UNTIL we turned on the electric switch for the Aqua Hot,,, Then we get 136. and. 110.!! We HAVE to be able to use the electric switch, as we are too close to our neighbors, and they wouldn't appreciate the diesel smell. I have a call into Rudy, so I KNOW everything will be ok. Without AH it's 120 ish.
Title: Re: Voltage problem revisited
Post by: wolfe10 on November 20, 2019, 05:19:11 pm
That still suggests that someplace the neutral conductor is not making good contact, wire broken, if cord reel may be poor contactor in it, etc.
You need to get this fixed before it "lets the smoke out" of some of your electronics from extreme low/high voltage.
Title: Re: Voltage problem revisited
Post by: turbojack on November 20, 2019, 06:06:45 pm
When you have a neutral problem the phase with the least load will have the greatest voltage and the phase with the greater load will have the lower voltage. The problem is everything that is on the phase with the highest voltage will not like the high voltage it sees and you may be buying a lot of new items.
Title: Re: Voltage problem revisited
Post by: GleamB on November 20, 2019, 06:37:54 pm
If all looks good UNTIL we turn on AH switch, wouldn't that indicate something at the AH??
Title: Re: Voltage problem revisited
Post by: craneman on November 20, 2019, 06:45:23 pm
If all looks good UNTIL we turn on AH switch, wouldn't that indicate something at the AH??
No, try your microwave and see if the same thing happens. Any big draw drastically changing your voltage means you have an electrical problem.
Title: Re: Voltage problem revisited
Post by: dsd on November 20, 2019, 07:00:10 pm
RV Safety | No~Shock~Zone (http://noshockzone.org/category/rv-safety/) You still have the same neutral problem. You need to get someone with a strong electrical background to look at it. Neutral problems can be difficult to understand. They will steal voltage from the other phase yet still read correctly. It's just not worth burning up electrical equipment, hurting yourself or someone else. The Nonshockzone book is in the first post on foretravel safety, well worth the read. IMO. Scott
Title: Re: Voltage problem revisited
Post by: GleamB on November 20, 2019, 07:09:27 pm
Just tried the microwave.....no change in voltage Finding an electrical expert in an RV park in Mexico....not likely
Title: Re: Voltage problem revisited
Post by: Shady Lady on November 20, 2019, 07:26:54 pm
Glenn, you could call Erik Kaasgaard at 669-269-6979. He's a Mobile RV Service Tech in Mazatlan. Cheers, Mike.
Title: Re: Voltage problem revisited
Post by: Barry & Cindy on November 20, 2019, 07:55:06 pm
Glenn & Amy,
Generally when one leg of 240v goes high and the other goes low, it is caused by a poor ground somewhere. Drawing high current on one leg can trigger the problem, that looks ok when there is not many amps being drawn.
Measuring things with a load gives a more real world reading.
Title: Re: Voltage problem revisited
Post by: wolfe10 on November 20, 2019, 07:58:16 pm
Actually, the load on the ground should be zero or close to it.
It is the NEUTRAL that is designed to act as the "reference point" for the two hot legs.
We are back to exactly what was said in the very first post on this thread!
Title: Re: Voltage problem revisited
Post by: FourTravelers on November 20, 2019, 10:29:10 pm
As stated before, check all of your neutral (white wire) connections from your power cord to your sub-panel for tightness. The power reel is a likely place for a poor connection. Is seems odd to me that turning on the aqua-hot would make a more drastic voltage swing than the microwave. I don't have aqua-hot so I am not sure of the amp draw but one would expect it to be less than a microwave.
The larger the imbalance of the load between L1 to N and L2 and N, will cause the voltage difference to be higher. They should still read around 220/240 between L1 & L2 and 120V to ground on each regardless of a loose neutral.
Check the neutral buss and conductor very closely in the panel that feeds the aqua-hot..............
Title: Re: Voltage problem revisited
Post by: GleamB on December 19, 2019, 12:53:20 pm
I was about to open the reel to check voltage, but realized the issue wasn't power at the post, but maybe was from the reel to the transfer switch. The monitor read 110 and 123. Now reading 106 and 132 !?? At the incoming transfer switch it read 115 and 116. Now I suspect the monitor. Am I missing something ? Why is the red incoming wire going to the generator side? Will post some photos
Title: Re: Voltage problem revisited
Post by: craneman on December 19, 2019, 01:49:54 pm
Go behind the monitor and read the voltages in the outlets it is plugged into. My monitor goes screwy sometimes.
Title: Re: Voltage problem revisited
Post by: GleamB on December 19, 2019, 01:51:54 pm
Photos
Title: Re: Voltage problem revisited
Post by: wolfe10 on December 19, 2019, 02:35:19 pm
When you get those unbalanced readings what are the voltage readings at that open ATS?
Title: Re: Voltage problem revisited
Post by: John Morales on December 19, 2019, 03:45:53 pm
Glen, remove the inside panel. It has two cords plugged into seperate outlets one for each leg. Unplug them and test the voltage at the outlets and compare to the meter. If the readings match the pedestal, something could be wrong with your inside panel. John M.
Title: Re: Voltage problem revisited
Post by: dsd on December 19, 2019, 04:37:59 pm
Glenn I had the exact same problem that I could not figure out for 9 months. If your voltage is above the normal single line/leg voltage you have a (poor neutral). The excess voltage is being robbed from the other leg. And as crazy as this sounds under load it will steal power from the other 220v leg and the voltage will go up on the loaded leg. Unloaded leg drops. This is not normal because generally the voltage drops with higher resistance. Genuinely I couldn't see the problem/understand right up until that's all I could see. You have a poor neutral. Load up the system and see what the leg with the hi load does. Voltage climbs with load? You have a bad neutral. In my case it was a untightened neutral in the city side of the power failing under load only. Read perfect with a meter. New construction I paid them to do. Scott
Title: Re: Voltage problem revisited
Post by: Pamela & Mike on December 19, 2019, 04:49:25 pm
Glenn,
Here is a description as to how to check your powerline monitor to see if it is the source of the problem from the other thread. Voltage Problem (https://www.foreforums.com/index.php?topic=38210.msg370601#msg370601)
Mike
Title: Re: Voltage problem revisited
Post by: turbojack on December 19, 2019, 04:54:20 pm
Why is the red incoming wire going to the generator side?
If your generator was to put out 240V then the red wire is needed. If your generator is only putting out 120v then at the generator they have the black and red wires tied together.
Title: Re: Voltage problem revisited
Post by: GleamB on December 20, 2019, 04:32:19 pm
It is the monitor !!! You think Jim fixes them?
Title: Re: Voltage problem revisited
Post by: craneman on December 20, 2019, 06:32:42 pm
I found a place in Canada that fixes them. I got the information off the forum, but not sure where.
Title: Re: Voltage problem revisited
Post by: Caflashbob on December 20, 2019, 06:51:22 pm
More work but I replaced mine with a blue seas M2 OLED gauge. Shows both legs versus one. Had to run a wire from the bathroom outlet through the cabinet bottom to access both legs. I think I posted a picture here?
Title: Re: Voltage problem revisited
Post by: DavidS on December 20, 2019, 07:42:38 pm
I found a place in Canada that fixes them. I got the information off the forum, but not sure where.
Had a friend resolder new led onto mine and whatever else was needed.. didnt look to difficult but I am still working on my Solder so no go for me..
Title: Re: Voltage problem revisited
Post by: craneman on December 20, 2019, 08:12:24 pm
Here is a link to where Dave posted about a repair.
Voltage monitor (https://www.foreforums.com/index.php?topic=27083.msg224673#msg224673)
Title: Re: Voltage problem revisited
Post by: Bob McGee on December 20, 2019, 08:17:53 pm
Flight Systems repaired mine about 7 years ago. Still working fine: https://www.flightsystems.com/
Title: Re: Voltage problem revisited
Post by: GleamB on December 21, 2019, 03:19:44 pm
My celebration might be premature. Today, the monitor read different numbers all morning. When it read 100 and 142 I went outside to check. Progressive Industries read about 116 each leg, which is normal at this RV park. I flipped off the breaker and turned on the generator. The monitor read 121 on both legs!!?? Turned off gen and went back to power pole. Checked outlet near stove....116. Can someone decipher this info for me? Is the reel still suspect??
Title: Re: Voltage problem revisited
Post by: craneman on December 21, 2019, 03:23:45 pm
When the voltages are reading off, check the outlets that the monitor is plugged into. If voltage is correct in the outlets the monitor is bad. Just disconnecting and connecting power can make the monitor work for awhile.
Title: Re: Voltage problem revisited
Post by: Dave and Nancy Abel on December 21, 2019, 04:55:55 pm
Can someone decipher this info for me? Is the reel still suspect??
Howdy Glen, IMHO your reel is definitely suspect and very likely the cause of your erratic voltage readings. As mentioned before, I would monitor your readouts and pull out (or retrieve) more cord and see if your readings change. Bad/worn brushes, burnt spots on the collector (brush) rings or both, will cause your symptoms. By moving the reel in/out you may find a "clean" spot, where the voltage is steady. I finally removed our Power Reel (for this very reason) and just manually coil/recoil the power cord. The Power Reel is very handy, but is possible failure point. Good Luck, Dave A
Title: Re: Voltage problem revisited
Post by: FourTravelers on December 21, 2019, 05:59:12 pm
Glenn If your monitor always works correctly when on generator power and only reads incorrectly on shore power, then yes......... I would say with reasonable certainty that your problem is between your ATS and the shore cable plug. The cable reel is a likely suspect, bypass it if you can and then see if the problem still exists. Sure sounds like you have a poor neutral connection somewhere.........
Title: Re: Voltage problem revisited
Post by: John Haygarth on December 21, 2019, 06:23:14 pm
Mine always reads way off down here and checking all outlets it is 123.4 on every plug and shows both legs at that too on the progressive monitor safety control. See picture of my readings JohnH
Title: Re: Voltage problem revisited
Post by: GleamB on December 22, 2019, 01:11:16 pm
Today monitor read 106 and 131. Progressive Industries read 116 and 116 Tested outlets behind monitor 116 and 116 Wouldn't mind getting monitor repaired Sent Jim a PM, but no response John....you think it's just a Mexico issue?
Title: Re: Voltage problem revisited
Post by: John Morales on December 22, 2019, 06:24:06 pm
Glenn, There is a calibration screw on the back of the monitor. One for each line. Adjust the reading to match your reading at the plugs. John M.
Title: Re: Voltage problem revisited
Post by: Michelle on December 22, 2019, 06:30:30 pm
Glenn, There is a calibration screw on the back of the monitor. One for each line. Adjust the reading to match your reading at the plugs.
If the voltage readings are fine at other camping locations, wouldn't adjusting the monitor be masking the symptoms rather than curing the problem? Not necessarily the best course of action if there is an electrical issue.
Title: Re: Voltage problem revisited
Post by: John Morales on December 22, 2019, 07:42:35 pm
Michelle, Reply 53 states that the voltage outside matches the voltage inside at the plugs behind the line monitor. So adjusting the monitor isn't going to mask anything. The monitor is not calibrated to the correct voltages. John M
Title: Re: Voltage problem revisited
Post by: Neal Pillsbury on December 23, 2019, 01:40:22 am
OK. This discussion is becoming dangerous. As Michelle pointed out, don't adjust meters to mask an electrical problem and Glenn, don't ignore the problem just because you are in Mexico.
We are on vacation, now coachless, so I'm away from my normal media equipment and I need to try to talk from hand drawn pictures, instead of the more desirable schematics, but (keeping this as basic as possible) here goes anyway:
From the second picture, normal single phase power gets to your coach via Power lines that have (typically) 2400 or 4800 or 7200 VAC electrical potential.
This is stepped down to two lines of 120 Vac potential through a center tapped power transformer on the power pole. That single phase power is carried throughout your building/house or RV Park as single phase, 180 degrees opposed, Line 1, Line 2 (at 120 Vac potential) and a neutral wire (at ground potential).
Using Ohm's Law (I=E/R, Current in amps is equal to Voltage in volts divided by resistance in ohms) and a simple drawing (first picture), if your combined load on L1 is 10 Ohms of resistance (oversimplifying, but not unrealistic), then 12 amps of AC current will flow through that equivalent load and back to the power source (Transformer Power Lines at the street), with 12 amps AC flowing through the neutral wire.
Now, at the same time, if your combined load on L2 equals 30 Ohms of resistance (oversimplifying, but not unrealistic), then 4 amps of AC will flow through that equivalent load and back to the power source (Transformer Power Lines at the street), with 4 amps AC flowing through the neutral wire.
BUT that 4 amps AC will flow in the opposite direction, because the transformer on the power pole has a center tapped secondary winding (equal number of turns in the windings, but wound in the opposite direction, therefore equal and opposite voltages and current flows that are proportional to the line loads). Center tapped is the typical design for the highest percentage of buildings and 120 Vac commercial use in America.
Thus the TOTAL current in the neutral conductor will be 8 amps AC.
Now open (fault) the neutral conductor, as shown in the first picture, second drawing . 240 Vac will be felt across the very same total of 40 Ohms of load. When this happens, by Ohm's Law, the current in the 240 Vac circuit will be 6 amps AC, the heavily loaded line (10 Ohm equivalent load) will (by Ohms Law) have only 60 Vac shown across it when you look at the coach's power meter - or any other meter. And if that load was all in lighting, those lights would suddenly become much dimmer.
At the same time, with an open (faulted) neutral conductor, the lightly loaded line (30 Ohm equivalent load) will (by Ohms Law) have 180 Vac shown across it when you look at the coach's power meter - or any other meter. And if that load was all in lighting, those lights would suddenly become very, very bright, just before they blew out.
Now it is easy to understand that if the loads are perfectly balanced (between L1 and L2) there will be 0 amps of AC current flowing in the neutral. So it's also easy to see that if you fault (open) the neutral in this condition, nothing changes (equivalent resistances and voltage drops all stay the same until you create some imbalance between the two sets of loads).
BUT, if your meter (built in or handheld high impedance [resistance] Volt-Ohmeter) shows a difference in voltages [L1 to L2]), you need to correct the neutral conductor problem, not ignore it or adjust readout instrumentation.
So how do you find the open or high resistance Neutral connection?
Well, the FT Xantrex Readout Panels are notorious for failed components and/or board foil on the neutral sensing circuit. Based upon percentages, that is a logical place to look first. It is near the end of the power circuits because it is downstream of both ABT's, power distribution panels and all incoming wiring. If you cannot reliably duplicate the problem at the readout panels, then split the train of incoming power on one leg and look for it there. Keep halving the power path until you capture the fault between two points and that point is the problem. Because the neutral path is shared and may get commoned-up in certain (unknown) places, you have to do L1 and then L2 loads and trains of power.
Keep in mind that if the fault is not at the Xantrex readout, each and every wire/contact/power reel brush/manual power plug/ABT or PI terminal connection/etc/etc., in the entire power path has nearly equal probability of being the problem, all the way from the center tap on the power pole transformer, to the park utility pole to your 50 amp plug and receptical, to the ABT's to the machine screws to the circuit breakers in your coach power panel to the outlet screws in the split duplex outlet at the readout meters. Going after this (Easter-egging it) in a random fashion will be very frustrating and usually non-productive.
But the neutral problem must be found and resolved. What Glenn is experiencing IS a neutral conductor power problem. Saying it only happens in Mexico is dangerous because if one of your power lines L1 or L2 in the coach has no load, then all of the loads on the other line (including you, if you happen to touch the wrong thing) are likely to have 240 volts applied to them. If you start opening up circuit breaker panel breakers, you could easily end up applying 240 Vac to your TV or Computer or other unforgiving recievers.
I have found this open neutral (or, more commonly, high resistance neutral conductor) condition to occur more frequently in Mexico and Canada than in the US. That has to do with different regulatory emphasis and different electrician mindsets.
AND, bear in mind that if the open neutral is in the park wiring, absent any load on the 50(or any) amp receptacle, the capacitive coupling in the power leads to your power pole may cause your high quality (high impedance) VOM to read L1 = 120 Vac, L2 = 120 Vac at the power pole. That is because when you use a high impedance meter, the meter does not draw enough current (doesn't have enough load) to drain the built up capacitance line voltage (charge) in the power leads.
Sorry for the long dissertation, but this was getting to be dangerous. Find the problem and fix it. Don't ignore or mask it. Too dangerous and it may well kill you or burn your house down.
HTH, Neal
Title: Re: Voltage problem revisited
Post by: FourTravelers on December 23, 2019, 08:35:00 am
Very good explanation Neal, and as you stated, the "loose neutral" problem is not normally a "broken" neutral but a high impedance one that won't show up if there is a "no load" condition and with only a VOM (meter) connected while troubleshooting that is what you would have.
My question was...... and I don't believe was answered. Does this condition only show up on shore power and never while running on the generator?
Knowing this WOULD narrow down the search significantly...............
Justin
Title: Re: Voltage problem revisited
Post by: Michelle on December 23, 2019, 09:11:39 am
My question was...... and I don't believe was answered. Does this condition only show up on shore power and never while running on the generator?
See Reply #48 - yes, voltages are good when running the generator, and the condition apparently only shows up on shore power.
Here are the 2 other topics on this issue (I would merge them in, but it would create a huge topic)
Voltage Problem (https://www.foreforums.com/index.php?topic=38210.0)
Power Cord Reel (https://www.foreforums.com/index.php?topic=38401.0)
Title: Re: Voltage problem revisited
Post by: wolfe10 on December 23, 2019, 09:15:24 am
Yup, if voltages read correctly when on generator, but not on shore power, it is NOT the gauge at fault!
Find and correct the problem. And, if resistance/poor connection on the neutral, the more unbalanced the load between L1 and L2 the further out of spec will be voltage. This will "let the smoke out" of appliances if too far out.
Title: Re: Voltage problem revisited
Post by: Old Toolmaker on December 23, 2019, 09:27:26 am
See Reply #48 - yes, voltages are good when running the generator, and the condition apparently only shows up on shore power.
Here are the 2 other topics on this issue (I would merge them in, but it would create a huge topic)
Voltage Problem (https://www.foreforums.com/index.php?topic=38210.0)
Power Cord Reel (https://www.foreforums.com/index.php?topic=38401.0)
Well that bit of information narrows the search to starting at the neutral connection on the power pole to the shore power contacts on the automatic transfer switch. Easy Peasey.
Title: Re: Voltage problem revisited
Post by: wolfe10 on December 23, 2019, 09:31:43 am
Well that bit of information narrows the search to starting at the neutral connection on the power pole to the shore power contacts on the automatic transfer switch. Easy Peasey.
Yup, and if shore power cord reel, add that (toward the top) of the suspect list.
So: Male end of shore power cord (assuming this has occurred at more than one pedestal so are ruling out bad power to pedestal).
Female end of shore power cord if no reel. Male receptacle on coach that shore power cord plugs into. OR reel and its contacts.
Shore power "IN" side of ATS.
Lastly and least likely, a wiring issue between these points. Most common if rodent damage.
Title: Re: Voltage problem revisited
Post by: Michelle on December 23, 2019, 10:12:24 am
So: Male end of shore power cord (assuming this has occurred at more than one pedestal so are ruling out bad power to pedestal).
Gleaned from first topic - discovered during first report of the issue that the original male end had a prong break off, male end was replaced (Reply #10 of this topic shows wiring and there is some discussion of that which follows that reply)
Title: Re: Voltage problem revisited
Post by: Old Toolmaker on December 23, 2019, 10:47:39 am
Gleaned from first topic - discovered during first report of the issue that the original male end had a prong break off, male end was replaced (Reply #10 of this topic shows wiring and there is some discussion of that which follows that reply)
And reply #25, Voltage problem revisited (https://www.foreforums.com/index.php?topic=38296.msg372038#msg372038) points to a problem with using modern high impedance digital volt ohm meters. The input impedance of these meters is in the millions of ohms range. So no load on the circuit under test.
Now the second trap of the ubiquitous (translate that as cheap) VOM is that most don't measure true RMS voltage. Now I freely admit I don't have the same level of education Mr. PIllsbury, but I have been living with an electronics engineer for 30 years. Now before I met Lynn I had learned to read RMS as Root Mean Square, FWIW here's the formula i cribbed from Wikipaedia, I should have it memorized but I don't:
"Peak values can be calculated from RMS values from the above formula, which implies VP = VRMS × √2, assuming the source is a pure sine wave. Thus the peak value of the mains voltage in the USA is about 120 × √2, or about 170 volts. The peak-to-peak voltage, being double this, is about 340 volts."
And herein lies the rub (again, that writer of bawdy stories) once you lose the neutral connection you can no longer assume that you have a pure sine wave. There are true RMS voltmeters but you won't find them at Harbor Freight.
Here is a nice lesson on voltage measurement:
Dual Impedance Digital Multimeters | Fluke (https://www.fluke.com/en-us/learn/blog/digital-multimeters/dual-impedance-digital-multimeters)
Finally, just as the man who wears three wrist watches never knows what time it is, pick one volt meter and stick with it. Don't go around recalibrating other volt meters until you measure the true voltage at the meter.
As Mr. Pillsbury said in post #57, Voltage problem revisited (https://www.foreforums.com/index.php?topic=38296.msg374968#msg374968)
"Sorry for the long dissertation, but this was getting to be dangerous. Find the problem and fix it. Don't ignore or mask it. Too dangerous and it may well kill you or burn your house down." Neal Pillsbury
And if Glenn and Amy Beinfest want to come this way, Marshall has some empty spaces in the trailer park* for $100/month and I'm willing to push Lynn out the door and say "don't come back until it's fixed." If you're willing to ask questions when your eyes glaze over, Lynn will teach you what you need to know.
*The nuclear plant team arrives in January.
Title: Re: Voltage problem revisited
Post by: Pierce & Gaylie Stewart on December 23, 2019, 10:55:20 am
How about leaving the shore power reel out of the loop and just borrow a normal cable to install and then check voltages?
Pierce
Title: Re: Voltage problem revisited
Post by: FourTravelers on December 23, 2019, 11:19:18 am
If your monitor always works correctly when on generator power and only reads incorrectly on shore power, then yes......... I would say with reasonable certainty that your problem is between your ATS and the shore cable plug. The cable reel is a likely suspect, bypass it if you can and then see if the problem still exists. Sure sounds like you have a poor neutral connection somewhere.........
Yep........... see reply #51, maybe the OP has tried that already?
If they were only closer to me I would (as most on the forum) be happy to find this problem for them.
I actually enjoy troubleshooting electrical problems, I've made a good living doing it the last 35 years...... ^.^d
Title: Re: Voltage problem revisited
Post by: GleamB on December 23, 2019, 11:57:01 am
Wish I could take advantage of the offers to help. I know I would learn a lot in the process. I guess I will try and bypass the reel ( which I have gotten REALLY fond of ), to see if that is the weak link. If it isn't, I'm not sure how to proceed.
Title: Re: Voltage problem revisited
Post by: FourTravelers on December 23, 2019, 12:19:39 pm
Glenn If it is the power reel, it could be just a case of dirty slip rings, poor contact connection. Possible easy fix no matter where it is..........just finding the problem is sometimes the difficult part. No need to not still have / use a power reel. Good luck!
Title: Re: Voltage problem revisited
Post by: Old Toolmaker on December 23, 2019, 01:36:10 pm
Wish I could take advantage of the offers to help. I know I would learn a lot in the process. I guess I will try and bypass the reel ( which I have gotten REALLY fond of ), to see if that is the weak link. If it isn't, I'm not sure how to proceed.
Oh goody! I love spending other people's money.
Next step, hit the electrical supply store, Home Depot or Lowes and purchase "enough" 4-wire cable sized for 50A, a plug and whatever you need to connect it to your coach. Disconnect the reel, and wire in the new cable. Then go around with your VOM and check voltages both unloaded and under load the in input connection.
Title: Re: Voltage problem revisited
Post by: GleamB on December 24, 2019, 12:28:28 am
I was kinda hoping to avoid buying wire/plug as mentioned. I thought that when I opened the junction box ( riveted ) that I could use the existing cord to join the line going into the transfer box with wire nuts. Am I dreaming ?
Title: Re: Voltage problem revisited
Post by: craneman on December 24, 2019, 01:28:59 am
That would be the same as making another cord up. As long as disconnecting the cord from the reel isn't too difficult.
Title: Re: Voltage problem revisited
Post by: Neal Pillsbury on December 24, 2019, 02:48:24 am
................I thought that when I opened the junction box ( riveted ) that I could use the existing cord to join the line going into the transfer box with wire nuts. Am I dreaming ?
Glenn, What riveted junction box are you talking about?
What evidence have you come up with that convinces you that the problem is in the power reel?
I would agree with taking the power reel junction box apart (is it the end bell that you are talking about?), but only if you can reliably repeat the problem symptoms of good voltages at the utility pole female receptacle while at the same time, the 120 Vac voltages at the ABT shore power/gen set inlet relay (your first ABT in line with shore power) shows bad readings. If you can do that , then the problem is in between those two points, which points strongly to the power reel.
Only then would I go to all of the trouble of dismounting and taking the power reel apart to look for anomalies. The power reel connections, inside the end bell, in any power reel that I have ever worked on, are very tightly packed and have little forgiveness regarding lengths and positioning. Also, unless you are very confident in what you are doing, you should not power up the power reel while it is partially disassembled, which would be required if visual inspection does not yield any apparent or real evidence of a problem. I've attached some photos of the inside of my 1998 U270 Power Reel.
The female receptacle on the utility pole and the ABT relay terminations, on the other hand, are (usually) much easier to access than the power reel innards are. I'm assuming that your ABT is under the foot of your bed and that you only have one ABT while your second ABT (shore power/inverter ABT) is contained within your Inverter/Charger
HTH Neal
Title: Re: Voltage problem revisited
Post by: Chuck & Jeannie on December 24, 2019, 08:48:47 am
COOL photos of the inside guts of the power cord reel! ^.^d
Title: Re: Voltage problem revisited
Post by: Old Toolmaker on December 24, 2019, 10:19:28 am
I was kinda hoping to avoid buying wire/plug as mentioned. I thought that when I opened the junction box ( riveted ) that I could use the existing cord to join the line going into the transfer box with wire nuts. Am I dreaming ?
No, but now that you're past that brain cramp you have your choice of three places to measure the voltage while your system is under load. At the plug into your power pole. At the automatic transfer switch. And if the voltage is off coming into your ATS, the connections on your cord reel.
Amazing how the thought of parting with money spurs the thought process along.
Art BTDT.
Title: Re: Voltage problem revisited
Post by: craneman on December 24, 2019, 10:22:53 am
Glenn, What riveted junction box are you talking about?
What evidence have you come up with that convinces you that the problem is in the power reel?
I would agree with taking the power reel junction box apart (is it the end bell that you are talking about?), but only if you can reliably repeat the problem symptoms of good voltages at the utility pole female receptacle while at the same time, the 120 Vac voltages at the ABT shore power/gen set inlet relay (your first ABT in line with shore power) shows bad readings. If you can do that , then the problem is in between those two points, which points strongly to the power reel.
Only then would I go to all of the trouble of dismounting and taking the power reel apart to look for anomalies. The power reel connections, inside the end bell, in any power reel that I have ever worked on, are very tightly packed and have little forgiveness regarding lengths and positioning. Also, unless you are very confident in what you are doing, you should not power up the power reel while it is partially disassembled, which would be required if visual inspection does not yield any apparent or real evidence of a problem. I've attached some photos of the inside of my 1998 U270 Power Reel.
The female receptacle on the utility pole and the ABT relay terminations, on the other hand, are (usually) much easier to access than the power reel innards are. I'm assuming that your ABT is under the foot of your bed and that you only have one ABT while your second ABT (shore power/inverter ABT) is contained within your Inverter/Charger
HTH Neal
Neal, are the 2 sets of brushes for redundancy or does it take 8 connections to work? Also is the abt the same as the ats?
Title: Re: Voltage problem revisited
Post by: dsd on December 24, 2019, 01:01:05 pm
Neil. Thank you for posting great information. I must admit from your photos I have REEL ENVY. What is the normal recommended inspection and preventative maintenance that should be performed on these brushes, slip rings? Thanks Scott
Title: Re: Voltage problem revisited
Post by: John Haygarth on December 24, 2019, 02:40:15 pm
Since reading Niels post I have been checking all connections etc on incoming lines and found no issues. I was going to run a spare 50amp line to another outlet that shows equal legs on friends CC hook up but thought I would first just connect to the 30amp outlet on this box as we do not need air and extra power so did it and have voltage readings at 113 so am staying this way for a few days to see if this works out. The readings on the other coach hooked up to the box I was thinking of show equal at 123v, so that may have helped me sort some possibilities out. We have solar and lots of sun so do have back up if needed. JohnH
Title: Re: Voltage problem revisited
Post by: FourTravelers on December 24, 2019, 02:45:12 pm
Parallel brush sets, less current per brush so smaller brushes required.
Title: Re: Voltage problem revisited
Post by: Caflashbob on December 24, 2019, 03:03:23 pm
The only perfect machine has no moving parts. Hence the cable master cord reel. As time goes on like the steering boxes more and more reel craft cord reel issues will show up. Or you can be proactive and put in the glendinning cable master. Most of the industry changed to no slip rings. Yes you will lose your water hose reel on some models.
Title: Re: Voltage problem revisited
Post by: Neal Pillsbury on December 24, 2019, 04:47:48 pm
Neal, are the 2 sets of brushes for redundancy or does it take 8 connections to work? Also is the abt the same as the ats
Chuck, Sorry ABT = ATS.......... Not the same in the Navy and in commercial power, but used interchangeably in our applications: ABT = Automatic Bus Transfer (typically 3 or more switched conductors) ATS = Automatic Transfer Switch (typically just 1 or 2 switched conductors) I don't know why our switch company name is ATS.
In actuality, there are 16 brushes. You see 8 in the photos, but there are another 8 that are hidden under the wires and the wire nuts. Each arbor has 8 rockers on it and each rocker has a spring loaded brush on it. You are looking at the reel first with wires showing and then (180 degrees) at the reel with the unobstructed brushes showing. So: 4 slip rings (for L1, L2, N and Ground) 2 brushes for L1 in (opposite sides of the slip ring), 2 brushes for L2 in, 2 brushes for N in, and 2 brushes for Ground in Then on the other rack (arbor), repeat the same 8 for the "out" wiring As already pointed out, more current paths = smaller conductors and increased reliability. HTH, Neal
..........What is the normal recommended inspection and preventative maintenance that should be performed on these brushes, slip rings?...............
Scott, I've never seen any preventative or predictive maintenance recommendations but I have worked on reels that are 30 to 35 years old and they looked just as good as what you see here (the pictures are of a 14 year old reel). What IS key is to NEVER move a reel when there is power applied to it. Moving the reel will cause arcing and burning of both the contact "brushes" and the slip rings.
I took these pictures when I was changing the reel from 25' of cable to 40' of cable. OEM by FT was 25', but the cable had a double thick SO outer cable covering. That is great to protect a power cable from abuse. Good for a lot of FT owners, from my experience. But 1/2 that thickness of SO protective cover is fine if treated properly and reasonably. Then one can spool nearly double the length of cable onto the reel and the cable is much easier to handle by hand.
I wouldn't have taken the reel apart, if it hadn't been for the cable changeout. HTH, Neal
.................Most of the industry changed to no slip rings. ................???????
Bob, Agree. Lots of moving parts in the Reelcraft Reels. But used properly, I disagree that they are problematic. I've not experienced one or worked on one that failed due to moving parts. I've worked on a couple of reels that have been abused:
Operator didn't stow the cable, drove over the cable and ripped it out of the reel.
Operator thought that he was supposed to use the reel like a vacuum cleaner power cable retrieve mechanism (allowed it to free spool into the end stop every time he used it).
[/list] The Reelcraft and Glenndinning Cable Master "spooling" concepts have about a 1::4 volume difference: The Glenndinning uses up 3 to 4 times as much volume in a volume limited environment. HTH, Neal
Title: Re: Voltage problem revisited
Post by: Barry & Cindy on December 24, 2019, 07:06:43 pm
Never moving reel when power is flowing across brushes can be difficult when even stepping on extended cable can move the reel a small amount, causing a burned brush/commutator. Be nice if reels could be firmly locked before applying power and unlocked only after power is turned off.
To bypass reel, removing cable from reel, joining cable-wires with transfer-switch-wires, using wire nuts inside a metal or non-metal electric junction box is just fine. Anchor cable so there is no pulling-stress on wire nut splice.
As an option for greater flexibility mounting a permanent male connector and using a female cord end is what non-reel coaches have.
For even the BEST by far, use SmartPlug bulkhead male connector with a Smartplug female cable end. Many of us use this setup and will never go back to Hubbell-style twist plugs.
Over time many electric reels develop serious problems, sometimes starting with just a small amount of resistance.
Title: Re: Voltage problem revisited
Post by: GleamB on December 24, 2019, 10:27:26 pm
Just Googled Smart Plug bulkhead connector.... Got a 7 prong looking thing Can you be a little more specific please
Title: Re: Voltage problem revisited
Post by: Jack Lewis on December 25, 2019, 04:37:23 am
RV Smartplug.
SmartPlug is the Easiest RV Power System | RV power outlet (https://smartplug.com/smartplug-is-the-easiest-rv-power-system/)
Title: Re: Voltage problem revisited
Post by: wolfe10 on December 25, 2019, 09:01:36 am
I would NOT start buying new pieces until you have identified the failure point. Troubleshooting by throwing parts at it is ............
Again, unless wires have been attacked by mice, you only have a couple of possible failure points:
Male end of shore power cord Reel end of shore power cord to house wiring ATS IN side
Because this does not occur on generator, you can rule out ATS OUT side and further.
Title: Re: Voltage problem revisited
Post by: GleamB on December 25, 2019, 12:25:21 pm
Twig and I checked outlets on both inverted and non inverted circuits, behind monitor, at refrigerator and other outlets. All were fine. It is the monitor. I sent Jim a pm, but later read he does not repair them. Someone had posted that there was a place in Canada where it might be done, but offered no specifics. I will not attempt to repair it myself. I WOULD like to get it repaired. If anyone has info they can share, I would appreciate it. Thanks for all the well meant advice.
Title: Re: Voltage problem revisited
Post by: craneman on December 25, 2019, 12:28:45 pm
Reply #46 and #47 for repair.
Title: Re: Voltage problem revisited
Post by: GleamB on December 25, 2019, 01:06:47 pm
Oops.... Thanks, Craneman. I had written that down a while back....then got sidetracked.
Title: Re: Voltage problem revisited
Post by: John Morales on December 25, 2019, 01:30:20 pm
Glenn, Craneman posted 2 years ago where he sent his monitor to be fixed. Check out the posting. John M.
Power Line Moniter (https://www.foreforums.com/index.php?topic=32105.msg285856#msg285856)
Title: Re: Voltage problem revisited
Post by: DavidS on December 25, 2019, 01:41:39 pm
All Spectrum Electronics - Hobby Kits and Electronics Supply (http://www.allspectrum.com/)
Power Line Monitor Is On The Fritz (https://www.foreforums.com/index.php?topic=9866.0) reply 13
OK, I went out and pulled my monitor out and opened it up.
The steps to open it are: 1 Remove front panel from electrical box - 4 screws 2 Unplug 2 cables from front panel to power supplies 3 Remove 4 hex nuts and remove board from front panel
The 4 NE-2G green bulbs are 6 x 12 mm. There are also 2 plain NE-2 (amber) 6 x 12 mm bulbs for the open ground indication. I didn't touch the circuit of these 2 bulbs as they are almost never (hopefully!) lit, and should last forever.
I replaced the original series resistors with 470k for long life and not too dim a bulb for the 4 green bulbs. Before you change these resistors, you should follow the traces and verify that your board layout is the same as mine (2000 U-270).
The attached photo shows these as well as the adjusting pots to calibrate your volt meters. Just be careful of the high voltage, both as for shorting anything while it is hot, and coming into personal contact with any high voltages!
Dick
Title: Re: Voltage problem revisited
Post by: Barry & Cindy on December 25, 2019, 05:37:15 pm
5 years ago and still one of the best improvements we have made to our coach.
We did the Smartplug install ourselves:
SmartPlug 50 Amp Shore Power Cable Installation (http://beamalarm.com/Documents/Modifications/smartplug-50-amp-shore-power-cable-installation.html)