Electrical questions

Topic: Electrical questions (Read 1452 times) previous topic - next topic

Electrical questions

October 18, 2020, 09:22:24 am

On the road, again.
First question....on my 2001 U320, there are two outlets, floor level, under the sink. They are "hot" when on land line or generator, but NOT when inverting. Any idea why? Not a big problem, just asking...
Second question...My Magnum 1283? is set to my generator to come on at 12.2 v
The gen fires up for about 14 minutes, reaches 13.0, and turns off. I want it to stay on to charge the batteries. I reread the manual for the nth time, but am a dummy with this issue ( and others !).
Anyone know how to set the control to bulk/ absorb for a longer period of time.
Thanks

Re: Electrical questions

Reply #1 – October 18, 2020, 09:45:23 am

There are only certain circuits on the inverter to keep from overloading it. The outlets you mentioned must not be on the inverter circuits. In my coach the circuits on the inverter are in the smaller breaker box on left side of the foot of the bed. There is also an automatic transfer switch in the compartment between the engine and the foot of bed that switches from the shore power/ generator to the inverter

Re: Electrical questions

Reply #2 – October 18, 2020, 10:46:29 am

Floor level outlets seem best suited to powering something like, say, a portable vacuum cleaner or similar device. Not exactly a mission critical component (like a residential fridge or an ice maker) that must be kept running every single day, so why waste precious battery power? Instead, the designers intended that those outlets would only be used when connected to (unlimited) shore power, or when running the generator.

Re: Electrical questions

Reply #3 – October 18, 2020, 11:00:33 am

Quote from: GleamB – October 18, 2020, 09:22:24 am

On the road, again.

Second question...My Magnum 1283? is set to my generator to come on at 12.2 v
The gen fires up for about 14 minutes, reaches 13.0, and turns off. I want it to stay on to charge the batteries. I reread the manual for the nth time, but am a dummy with this issue ( and others !).

I'd like to try and help on this lazy Sunday, but all I have available to me are pretty dumb systems. So all I can do is ask you questions about your system. If it helps, think of this as the Socratic method of teaching. Me? I've always thought of this as "Finding the right question to ask."

Art

So. Tell me a little bit about your system. Does your inverter charger start and stop your generator? Or, Does your generator handle that part on its own?

Re: Electrical questions

Reply #4 – October 18, 2020, 12:14:44 pm

Glenn, take a picture of these outlets. Floor level under the sink? Next to the AH in and out vents? We do not have floor level vents below the sink and outpr coach is pretty close to yours. Maybe they were added by a PO. I would think cords plugged in at that location would be a trip hazard or perhaps subject to water spills.

If your gen autostart comes on at 12.2 volts then you are seriously close to 50% SOC and it will take a couple hours of generator time to begin to replenish your deficit. Turn off voltage setting should be higher and the minimum run time setting should be more like 2 hours or more.

Re: Electrical questions

Reply #5 – October 18, 2020, 12:44:40 pm

Glenn,

My coach isn't that much older than yours. I have the two vents under the kick plate but no electrical outlets. I would suspect a previous owner added the outlets for some specific reason and either by choice or happenstance connected into a non-inverter line.

on further thought, a previous owner might have used them for space heaters, which of course you would not want on the inverter circuit.

Richard

Re: Electrical questions

Reply #6 – October 18, 2020, 01:48:35 pm

Our coach is wired similar to a stick home in that shore & generator electricity have two independent "Legs", usually identified as Leg-1 & Leg-2. Some appliances like roof air, battery charger etc are hard wired to one leg or the other. There is always an effort to try to balance loads, so each leg is not 'overloaded'. Some electric outlets are powered by Leg-1 and other outlets are powered by Leg-2.

Inverter ONLY powers one of the two legs, so right away anything on the non-inverter leg are dead. And the inverter does not power all the outlets on that one leg.

Some of us have over time identified which outlets are on inverter and which are on Leg-1 or Leg-2. You are now starting to identify how your coach is wired.

Re: Electrical questions

Reply #7 – October 18, 2020, 08:06:51 pm

Barry, you are probably aware of this but for the new folks that may not know --Yes generator provides 2 legs but they are the same phase. said another way the 2 legs together do NOT produce 240 volts. I have been told that you can change some wire in generator and get 240 volts but I have not consulted with the generator tech people to confirm this. Others may know what to do and chime in.
Chris

Re: Electrical questions

Reply #8 – October 18, 2020, 09:51:41 pm

Chris, I purposely stayed away from mentioning 120 vs 240 volt because the two legs can be the same phase, just like you said and is true for our 8kw generator.

I was amplifying that all electricity outlets are not on the same leg and that only one leg is live with inverter source, to try to give the original question an answer.

Re: Electrical questions

Reply #9 – October 18, 2020, 10:52:06 pm

Cris I had contacted Tech about changing to 240 volts and they said it could be done. I was thinking about doing it but I'm not
going to put in an induction stove so I left it alone.

Re: Electrical questions

Reply #10 – October 19, 2020, 12:43:17 am

Quote from: oldguy – October 18, 2020, 10:52:06 pm

Cris I had contacted Tech about changing to 240 volts and they said it could be done. I was thinking about doing it but I'm not
going to put in an induction stove so I left it alone.

Yeah, the generator (alternator) can easily be rewired to 120/240 3 wire by swapping 2 of the output leads in the control box, (to wire the 2 legs 180 degrees out of phase) and removing a jumper on the breaker. I'm in the process of refurbing our 10kw KSI, and verified this. Probably the biggest drawback to doing this is that the voltage regulator is 120V and would only regulate based on the leg it's connected to. If the load on the other leg were significantly different, that leg could over/under volt. On a typical coach, there's probably no reason to justify doing it. On the other hand, if one wanted to install 240V appliances, say, a roof top AC, this would make that possible to be run off the generator. Some other parts of the electrics would have to be rewired to make this work (Likely a simple task), but I haven't dug into that much. (Yet)

Greg

Re: Electrical questions

Reply #11 – October 19, 2020, 04:14:37 pm

Thanks Greg, I have thought about doing this since I installed a 240v clothes dryer. W primarily go post to post so I kicked that can down the road to a future date. BUT with all the projections of full campgrounds for 2021 I told DW we may need to rethink adding solar so we could at least Boondock if we wanted to see a particular area and only had BLM or Park land available with no hookups.
In that situation we probably wouldn't be washing or drying clothes because of water conservation and would not need the dryer.
I will probably look into it just in case I needed to hook get up to house during electrical failure. Always good to have options
Chris

Re: Electrical questions

Reply #12 – October 21, 2020, 10:02:49 pm

FYI, not all Power Tech generators can be re-wired for 240 volts.

Generators that are wired for only 120 volts will usually over-heat/melt/burn the white neutral wire and also the transfer switch contacts if both hot legs draw over 50 amps at the same time, especially if prolonged at one time or eventually over time. A good reason to rewire for 240 volts.

Rewiring to 240 volts may stress generator if both legs are not closely balanced. 120 volt generators never need to have legs balanced.

Re: Electrical questions

Reply #13 – October 22, 2020, 12:13:26 am

I suggest one contact Jeff at Power tech with the serial # of the generator. Some can some can't. When I inquired Jeff ( he is THE generator guru)recommended not doing it.

Re: Electrical questions

Reply #14 – October 22, 2020, 01:44:51 pm

In reply #12 Barry said: "FYI, not all Power Tech generators can be re-wired for 240 volts."

Barry, can you explain why that would be? Would 240 VAC generators have a single (240v) armature rather than the two 120 VAC armatures that most Foretravel generators have?

While it is easily possible, it is not SAFE to modify the wiring in our generators to supply 240 VAC to our power panels. The reason for this is that our generators have two 120 VAC armatures with only one having a voltage controller. The two hot wires (one from each armature) are shorted together in a junction box beside the generator. The two neutral wires are also shorted together in that same junction box. Because the generator hot and neutral wires are shorted together, the output amperage of each armature is exactly half of the generator output and the voltage output of the two armatures are identical. The output wires from that junction box to the main power panel are a red hot, a black hot (two hots), and a white neutral (one neutral) all engineered to carry 60 amps. The one neutral wire must carry the output amps of the generator (maximum 83 amps with 10K), while each hot wire carries only half of the generator output amps.

A 240 VAC appliance can be safely used with our 120 VAC generators in one of two ways; either by using two 120 VAC circuits (if the appliance has a centre tape) or by providing 240 VAC to the appliance via a transformer.

Re: Electrical questions

Reply #15 – October 22, 2020, 02:03:57 pm

CORRECTION:
In Reply #14 I said "each hot wire carries only half of the generator output amps".
The correct answer is that each hot wire will carry whatever the circuits connected to that hot wire demand, which could be the total generator output.

Re: Electrical questions

Reply #16 – October 22, 2020, 10:45:33 pm

Hi Wyatt, You have done more custom changes than many with your Foretravel so we appreciate your input.

We have an 8kw PowerTech and Jeff told me our generator cannot be re-wired for 240v.

Re: Electrical questions

Reply #17 – October 23, 2020, 12:28:40 pm

My old craftsman smart charger has various settings. The gel setting charges at 14.4 volts. Gels require 14.1

Re: Electrical questions

Reply #18 – October 23, 2020, 12:45:23 pm

I like your first sentence, My old craftsman smart charger has various settings. How many forum members are both old and smart?

First, I have not looked at the gel charge setting for the Sungoldpower inverter/charger and second, how many forum members have gel batteries installed? Seems like the AGM and LiFePO4 types are the present and the future of battery technology.

Pierce

Re: Electrical questions

Reply #19 – October 23, 2020, 12:55:25 pm

Pierce I agree. But every Unicoach ever sold had mk gels in them.

Agm's do not like short cycling and other than Lifelines cannot be equalized to restore lost capacity. depending on the brand may have cast posts and require regular cable maintenance from acid leaks. East penn no leaks. Forged posts

Li-ion is great from 34 to 104 degrees internally. No charge above or below those temps as far as I am aware.

Silicone batteries are different and starting to come around.

Re: Electrical questions

Reply #20 – October 26, 2020, 11:02:07 pm

I have no power to table lamp or spot light. I have checked all of the breakers that are under the dash in front of the passenger seat. All of them test ok. I do not know which breakers power these.

Re: Electrical questions

Reply #21 – October 27, 2020, 10:29:52 am

Check the fuses at the foot of the bed

SPLIT: Home power issues (split from Re: Electrical questions)

Reply #22 – October 27, 2020, 10:40:33 am

One or more of the messages of this topic have been moved to Around the Fire Ring as it is not related to OP's electrical issues or Foretravels

https://www.foreforums.com/index.php?topic=40920.0

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