Plugged in at campground to 50 amps, and line 1 shows 127v while line 2 shows 120v. Line one occasionally spikes to 142v. Going to try the 30 amp service and the 20 amp service to see what happens. Suggestions?
Update: When plugged in to the 30 service, using my 30 amp cord, Line one shows 127v and Line 2 shows 127v
I would ask them to move you to a different site and have their maintenance guy repair the electrical service on the original one for the next camper. That way, if it's more than a simple fix, you have a site that's got reasonable power.
Even better if you happen to have a multimeter and can show them it's the site power and not something within your coach.
Michelle
Brian,
I agree with Michelle, I would unplug from that pedestal before a power surge damages your coach. Do you have a surge protector?
I do have a whole coach surge protector installed. Unfortunately, the office is closed until tomorrow. First thing in the morning I'll have them repair or move me. I just check the power outlet at my site as well as the one next to me, and they both showed 240v...120v per side. :headwall:
When you plug into a 30 amp, both lines will read the 120 volt info, they are reading the same line, this is normal or should I say that is how my coach works.
Hey dave,
That's what my coach normally shows as well. This is the first time I ever had any issues.
I know in our '03, the over/under protection relay will trip if the voltage goes over (roughtly) 132V. So our coach plugged into that campsite would have the relay clicking all night long. It's not something many surge protectors would protect against if the overage lasts less than 5-8 seconds due to their sampling/response rate.
We were in a campground overnight where we had that problem (Cave Country in KY) and we unplugged.
Is it cool enough where you are to unplug and run off the inverter overnight for any 120V items (i.e. you don't need to run air conditioning)? I wouldn't feel comfortable leaving our coach plugged in under those circumstances, especially not having the over/under protection (I believe it was first used in the '03 coaches).
Michelle
Don't think 241VAC is that far out of line :-) depending how it was measured. If you go hot to hot with the meter probes, you should see double approx 120V if there is 220 at the post. Could be the post is incorrectly wired. How about a word from the electricity expert? Dave?
Pierce,
I measured each side to ground and the independently showed 120v. Measuring hot and hot showed 240v.
I'm not Dave (and I didn't stay at a Holiday Inn Express last night ;) ), but here's a good site that explains how to check the campground's 50A outlet
RV Electric (http://www.myrv.us/electric/)
Click on "Outlet Testing". The 2 outer vertical blades are hot, should measure around 240V between them. The U-shaped one is "ground", and the vertical opposite it is neutral. Should be 0V between ground and neutral, 120V between either hot and one of these.
The tricky thing is going to be capturing that overvoltage spike. If your meter has peak capability and you're patient you might be able to get it. Really more to prove to the campground that they have a problem and should move you.
Michelle
I'm noe Dave either! With that being the case, I'm going to unplug and run off the inverter. BTW, I've ben watching the panel in the coach for the past 30 minutes, and Line 1 has stayed on 127v while Line 2 has stayed on 120v. Thanks to all that helped!
You know what? If the campground isn't that full and you can check any "late arrivals" board for reserved sites, I'd just move to a site that seems to be OK (with your meter) and go in and explain first thing in the morning. Especially if after you plug in everything looks fine in your coach for a while - it will let you sleep easier.
You can always move back if they need you to after they fix the site, and if you explain that you checked first to see if they had any late arrivals coming into the "replacement" site, they shouldn't give you any flack.
Michelle
Michelle,
You must have stayed somewhere good last night ( and probably just as well you are not Dave :-). Nice site. Why didn't I say something like that? A good web site is worth a thousand forum words.
As they say on ebay: ++++++++
Good suggestion, Steve. But..it's dark..I'm hooked up with all of my other amenities..my tire protectors are on..and I want a cold one! :D I'll sleep fine unplugged. I checked the spot next to me, and the voltages read the same as at my site. I'll check to see if the voltage between the neutral and ground reads zero.
Thanks. I stayed in our FT last night. ^.^d :)) (the campground
is across the street from a Holiday Inn Express... hmmm.....)
-M
Got lucky and saw a maintenance worker outside. I showed him what was happening, and he's calling his electrician in the morning. When I measured left hot to neutral the volts read 120v, but when I measured between left hot and ground the reading was 124v. The right hot and neutral measured 120v, but the right hot and ground measured 117v. Between neutral and ground the reading was 1v. I'm not an electrician by any stretch, but these reading don't look correct. Just to make sure, I did the same at the site next to me and had the exact same readings. The maintenance worker said that the two power receptacles come off the same bus and are wired the same.
If you are reading across the two spade connections at the panel you should be 240-245V. That tells you you are getting both phases. One spade to upper/lower (ground/neutral) - 120-130V
What is a practical example of what would cause this condition?
I'm going to hazard a guess at a couple of things.
1) Improperly sized or high impedence neutral wire.
2) Voltage on campground "ground". Voltage is a differential reading. If the ground has a (phantom or real) potential the differential at the hookup might read 120V, but the one in the coach can read high if it's using a different ground reference. We had this once, opted to unplug for safety. Part of the cause was poor ground connections (high impedence/loose) in the campground
3) Something plugged into the same bus that is miswired; often "ground" and neutral tied together (big no-no). Return current from the neutral polluting the "ground", causing #2 above. A miswired RV (we believe) was the other part of the issue we experienced that I mention in item #2. Our issue was coincident with a clearly home-modified unit arriving in the campground and went away when they departed. We did find campground "ground" issues while debugging and fixing them helped somewhat, but didn't completely eliminate the problem.
I expect the more expert minds here will think of other scenarios.
Michelle
The 147 volt reading is way-way out of standard and dangerous to all concerned (electric equipment), the normal voltage range is 120/240 volt target, with that you have the UL acceptance range of +/- 10 %. Now looking at the 120 line, with the +/- 10% your range is 108 - 132 volt. I do not like either end of that range, but UL claims it is OK.
Same goes for the 240 volt reading. I am not too concerned at the 240 volt reading because I only use the 120 volt readings.
One could write a long long study on this subject starting when normal was 110/220 volt. Now normal is running closer to 125/250 volt. You can keep an eye on your monitor to keep your self happy and when things start going nuts, unhook from the power post.
For me, I am happy when the range is between 114 - 128 volt, that is on each leg, if your into the 240 reading, that would be 228 - 256 volt.
Same goes for the generator with the additional UL standard of +/- 5% for frequency, think 57 to 63 hertz/cycles, 60 is the target.
As usual FWIW.
For those interested, The generator overall has been more stable on voltage than the power company for 1 good reason, (I am referring to the Power Tech Gensets), while the generator is capable of 120/240 volt, Mine is connected for only 120 volt operation, this puts all 10 kw on the 120 volt line. Generators are regulated by the 120 volt sensing. If you were to have the 120/240 volt setup, still have the 120 volt sensing, as you load down one side of the generator, depending on which side, the voltage might stay very dependable because the regulator is on that leg, but if the regulator is on the other leg, your loaded side might drop way down, how far depends on how much load. This would also give you some crazy 240 volt readings. This is exactly why the 120 volt only generator is far better than having the dual voltage, also with the dual voltage, and say a 10 kw, on 240 volt you only have 5 kw per leg., So keep load balanced.
For the die hards, do you know if your power post is giving you true power or appearant power ? The generator is giving you closer to true power. Think power factor ???
Not a biggie, but depending on how well the power company is keeping tabs on their loads.
FWIW
Moved to a different spot this morning in a different row. Check the voltage before I moved; everything was fine. Coach is now plugged in and showing 122 on each line. :) The electrician is here checking my original spot. I'll report his findings as soon as he informs me.
Dave,
I did read that the 10Kw PT is capable of 120/240 operation. We live out in the country and lose power several times a year. I have connected to the 120 and powered up the house but our well is 240V. How much trouble is it to attach a box with 240 out to the PT? Downside?
And, yes I do make sure the mains are switched off before I power up the generator. Was thinking of an automatic changeover also.
Pierce,
I have not looked at the Power Tech wiring to see how they have it configured, but with the two breakers on the panel, it should not be too hard to swap on to get the 240 output.
If I can find the wiring diagram for the Power Tech as installed in my coach It should be fairly simple to swap the one winding to get it out of phase to get the 240 output. Will take a look see.
Dave M
Here is a diagram showing what is needed to revert to 240 vac.
Remove Jumper and reverse these 2 wires.
Barry, That is correct, BUT DISCONNECT wiring from coach before you start this conversion.
Make sure you do not attempt to power up the coach with this configuration or you will have a *#$&^#((!! or a mess. When you play these non normal games, you best keep a clear head or it will clear your wallet.
Cheers
Thanks to Barry for the PDF and Dave for the "disconnect" tip.
We live at 1900 feet and can get snow several times a year. Were without power for a week several years ago. I can pull up to within 5 feet of the house so is easy to bring cable to the 220 plug I installed for my compressor.
Thanks again.
Dave M,
If you change the wiring per the diagram that Barry presented, don't you just create a 240 VAC split phase system that is the same as what you would normally get when plugged to the 50A pedestal?
Granted, the sensing is probably still based on 120VAC on one leg. My understanding is that the PT is wired as 120VAC to maximize use of the generator's capacity in a situation where the load is likely to be relatively unbalanced between the legs of a split phase system.
J D,
You may be right, if that is the case, why not convert your generator to the 240 volt system, and at the transfer switch, install an additional manual or electric operated contactor, where you can back feed the 50 amp line to the house/pedestal. This would make for a simple hookup to the house.
You could leave this setup as a normal convenience. This of course would only provide 25 amp per leg, half of the 50 amp line, but what ever the genset is rated at.
Thanks
Dave M
I had a 50 amp plug installed in my electronic bay run off of the generator. It was originally to hook up to the stick house for power outages. I havn't got around to putting in the transfer switch on the house side yet :(
I found another use for it. I can have another coach plug into it if there gen is not working to give them temporary power from my gen.
It looks like the generator will deliver rated current from each leg in a split phase configuration, i.e., 50 amps on each leg from 12KW, 44 amps from 10KW, and 33 amps from 8KW. The 120VAC only configuration is the preferred configuration in most RVs. At 120VAC, the generators would be rated to deliver a total of 100 amps for 12KW, 88 amps from 10KW, and 66 amps from 8KW.
We too have a 240VAC pump in our residential water well. I looked into using the PT-10 in the FT as an auxiliary generator. I decided to leave the PT-10 as is. If we want auxiliary power for the water well, we should put in a stationery generator with a proper transfer switch. So far, we have addressed the issue by keeping the FT near the house and ready for occupancy in case of failure of electricity, air conditioning, water well, etc.
The citation below gives a good explanation of why the preferred configuration for RVs is 120VAC only.
From http://powertech-gen.com/wp-content/uploads/2010/04/OPERATORS-MANUAL-PT-8-10-12.pdf (http://powertech-gen.com/wp-content/uploads/2010/04/OPERATORS-MANUAL-PT-8-10-12.pdf) :
"The generator may be connected at the terminal board to deliver 120/240 volts to a 3 wire grounded neutral system, or 120-volts only to a 2 wire distribution system. If any equipment requires 240-volts, then the 120/240-volt connection must be used. If all equipment requires 120-volts then the 120-volt connection is preferred, even if two lines leave the same switch box. The two lines at the inputs to the switch box are both connected to the un-grounded 120-volt lines from the generator. The 120-volt connection enables the Electronic Voltage Regulator (EVR) to hold the voltage very close to the 115 or 120 volts, as initially adjusted, regardless of the power distribution amount the different distribution lines. The 120-volt connection is recommended if the entire electrical load requires only 115 or 120 volts.
Although the 120/240-volt connection may also be used when all loads requires only 110 volts, it should be pointed out that this connection, the 240-volts, is regulated and the lightly loaded phase, or line, will deliver a high line to neutral voltage and the heavily loaded phase will deliver a low line to neutral voltage. The heavily loaded line may have such a low voltage that air conditioning will have more difficulty in starting, and long starting lines may overload generator and trip circuit breakers."
The problem, as told to me by the maintenance guy, was that the neutral and ground were wired together. They checked four of the 20 parking spaces in the row and found all four to have been wired as such. Seems to be the only row affected.
I wonder how many RVers future damage you and your FT's power line monitor readout just prevented? ^.^d
Michelle
This post provides additional information to that provided by J. D. Stevens, who got me started with his post.
Thank you Mr Stevens.
THE POWERTECH MANUAL INDICATES:
The generator may be wired at the terminal board to deliver either:
120/240 volts to a three wire distribution system, or
120 volts to a two wire distribution system.
INFORMATION ON: 120/240 - three wire distribution with two hots (red & black wires) and one neutral (white wire)
If any equipment requires 240-volts, then the 120/240-volt connection must be used.
Although the 120/240-volt connection may also be used when all loads require only 120 volts, this is not recommended.
The Electronic Voltage Regulator (EVR), will hold the voltage very close to 240 volts. When the two hot lines are evenly loaded, they will both be close to 120 volts, however, when the two hots are unevenly loaded, the heavily loaded line will have low voltage (ie 90 volts) while the lightly loaded line will have high voltage (ie 150 volts). The total voltage between the two hots will be regulated to 240 volts, but.....
INFORMATION ON: 120 - two wire distribution system with one hot (red or black) and one neutral (white).
If all equipment requires 120-volts then this is preferred because the two generator hot outputs are shorted together at the generator such that they each provides exactly half of the amperage demanded. This enables the Electronic Voltage Regulator (EVR), to hold the voltage very close to 120 volts on both hots, regardless of the power distribution amoung the different distribution lines.
WYATT'S RAMBLINGS:
The 120 - two wire seems confusing because the wiring on my Foretravel from the generator to the panel is a three wire distribution with two hots and one neutral. In reality, while there are two hot wires, a red and a black, these wires are shunted (shorted together) at the generator, such that the two hots from the generator each provide exactly the same amperage (perfect balance). Note that the "red hot" and "black hot" wires from the generator to the panel will not carry the same amperage, but will have the same voltage.
It seems that Foretravel has provided the three wire distribution from the generator to the panel such that folks needing 240 volts can just simply rewire at the generator. Unfortunately, Foretravel only provided 50 amp neutral wiring from generator to panel, while 100 amp neutral wiring is required. In a previous post, damage caused by overloaded neutral wiring was eluded to. I now understand why the neutral generator contacts in the automatic tranfer switch, which I replaced with 65 amp manual switches, was discoloured from overheating (this is frightening to me).
The solution recommended in a previous post is to not exceed 50 amps, which means I carry around a 700 pound, 10KWatt generator but can only safely use 6 kilowatts.
I believe, for most folks, a good solution is to run another #6 neutral wire from the generator to the transfer switch and on to the panel after installing a 100 amp transfer switch.
Another solution is to convert the generator output to 120/240 and load balance. Install another power watch voltmeter so you can see the voltage on each hot line. Load balancing could include: run both a/C units not just one, use two electric ceramic heaters with one on each hot, assure that the electric hot water heater is not on the same hot as the microwave. Foretravel has done a reasonable job of load balancing between the two hot lines and I believe this could be preferred to an overloaded neutral line. However, I have no idea how much unbalanced load can be tolerated, ie 10 amps or 30 amps! Does anyone know?
Other solutions, would be to put a fuse in the generator neutral wire, or replace the 10K generator with a lighter 6K generator.
FWIW
You really can't just 'add' another voltage regulator to the other phase. You can sense from one side to the other - but you only have one armature to apply voltage to create the multiple phase output. You have to properly balance loads.
I totally agree with you Dave.
I dusted off the old engineering manuals and did some calculating and if my assumptions and calculations are correct, rewiring your Powertech for 240 volts and using circuits on 120 volts is very dangerous and will result in disaster.
If demand at the panel for 120 volts is 20 amps & 30 amps, the voltages will be 145 & 95, which is not useable. If demand for 120 volts is 10 amps & 30 amps or worse yet, 0 amps & 30 amps, well, you just do not want to go there.
I would love to hear from anyone who has successfully rewired their Powertech generator for 240 volts while still using 120 volt circuits, because I do not believe it can be done.
Wyatt,
It can be done, at least it could on my 2000 U320. However, I didn't do it, Power Tech did it at their Florida facility. It was a pretty simple change and they had mine changed and a 50 amp outlet installed in less than two hours and that included them going out to pick up the 50 amp outlet. They called Foretravel first and asked if they had any problem with them making that change and they did not so Power Tech went ahead and did it. I would suggest that Power Tech is who you need to be talking with.