Unique Electrical Issue

wnytaxman · 04-29-2013, 10:09 AM

We have a 2011 Berkshire on a 2009 chassis (no DEF required) and I have a unique situation with my electrical system. When I am plugged into shore power of 50 amps I still have a 9 amp draw even with both the house and chassis batteries shut off. I can hear a humming noise from above the battery banks when I'm plugged into shore power and with all shut offs in the off position. I didn't notice the issue prior to the inverter being changed. That doesn't mean that I think it may be the new inverter, only that I didn't notice the issue before this.

Does anyone have any suggestions on where to look? My first thought was my block heater may be the issue, but I still have the draw with the block heater unplugged. Now I'm just scratching my head.

vannbranch · 04-29-2013, 10:16 AM

Disconnect the new inverter?????

boowho · 04-29-2013, 11:33 AM

Quote:

Originally Posted by vannbranch

Disconnect the new inverter?????

That may not help him, as I THINK all the 12 volt power (even from the batteries) goes through the inverter. If I'm wrong on this someone will "slap me down"

IF that is the case, then the draw could be coming from anywhere; although he did say it happens with all the master switches turned off

My GUESS would be that the chap that changed out the inverter wired it incorrectly. But then I always tend to blame the tech......

Boowho??

cfsoistman · 04-29-2013, 11:50 AM

Quote:

Originally Posted by wnytaxman

We have a 2011 Berkshire on a 2009 chassis (no DEF required) and I have a unique situation with my electrical system. When I am plugged into shore power of 50 amps I still have a 9 amp draw even with both the house and chassis batteries shut off. I can hear a humming noise from above the battery banks when I'm plugged into shore power and with all shut offs in the off position. I didn't notice the issue prior to the inverter being changed. That doesn't mean that I think it may be the new inverter, only that I didn't notice the issue before this.

Does anyone have any suggestions on where to look? My first thought was my block heater may be the issue, but I still have the draw with the block heater unplugged. Now I'm just scratching my head.

Is the Inverter Running? Mine charges the batteries when plugged in, even with the disconnect off to the rest of the 12 volt system of interior lights etc. Your steps into the coach and LP detector usually are not off when the 12 volt switch is in the off position either.

**wmtire** · 04-29-2013, 11:53 AM

Quote:

Originally Posted by wnytaxman

We have a 2011 Berkshire on a 2009 chassis (no DEF required) and I have a unique situation with my electrical system. When I am plugged into shore power of 50 amps I still have a 9 amp draw even with both the house and chassis batteries shut off. I can hear a humming noise from above the battery banks when I'm plugged into shore power and with all shut offs in the off position. I didn't notice the issue prior to the inverter being changed. That doesn't mean that I think it may be the new inverter, only that I didn't notice the issue before this.

Does anyone have any suggestions on where to look? My first thought was my block heater may be the issue, but I still have the draw with the block heater unplugged. Now I'm just scratching my head.

wnytaxman, just to make sure I am understanding correct.......are you having a 9 amp DC draw or a 9 amp AC draw?

The reason I am confused, as you are talking about inverters, which convert DC (battery) power into AC power.

You are also talking about being plugged into AC 50 amp shore power, but with your batteries (DC) being shut off.

There's no chance you are referring to a converter (AC to DC) instead of an inverter (DC to AC)

**Herk7769** · 04-29-2013, 12:00 PM

I would try to isolate that "humming" noise.

Use a paper "cone" and an ear plug in your opposite ear to try and isolate it.
9 Amps of anything is a lot of power.

TURBS · 04-29-2013, 12:04 PM

Water heater amps in reference is 10 - 11 amps!

**Herk7769** · 04-29-2013, 12:29 PM

Quote:

Originally Posted by f1100turbo

Water heater amps in reference is 10 - 11 amps!

True, but I can't believe it is powered off the inverter.

mogman · 04-29-2013, 12:29 PM

Is it the LP detecor solenoid on the Propane tank?? its always on.

wnytaxman · 04-29-2013, 01:52 PM

I thought about the Propane detectors and the fire alarms, but the draw is pretty high for that. I use a Progressive Surge Protector and when I plug the coach into the Surge Protector, it reads 9 amps as being drawn. I would assume that is AC.

The way this came to the forefront is that where I have inside storage we also have a 50 amp hookup. I usually would leave the unit plugged in during winter storage just as a convenience for winter starting. My landlord called one day questioning his electric bill and telling me that it appeared to be my coach which was causing the problem. Sure enough, it was mine that was continuing to have a fairly substantial electrical draw even though the house, chassis, and interior shut offs were all in the off mode.

I'm not mechanically or electrically inclined, so if I sound dumb on something, it's because I am! I'm trying to isolate what the problem may be or where it may be before I take the plunge of letting the techs at it.

Ed

Himcules · 04-29-2013, 02:07 PM

your progressive surge protector is reading AC draw from the shore power outlet.

from shore power to your coach, it hits the automatic transfer switch (silver/gray box) first then into the coach's sub panel's main breakers. all the outlets including the one next to the inverter connect back to the sub panel (under the bed).

the inverter has an automatic transfer switch inside of it as well to switch from battery to shore power for the outlets it powers (mainly the entertainment media outlets).

the inverter also has a converter on it to charge the batteries. chances are what you are hearing is the fan from the converter as it's charging your batteries because it has shore power. this converter/charger also charges the chassis batteries.

**wmtire** · 04-29-2013, 02:15 PM

Here are some charts/schematics of how the electrical may work in your coach. You could have an inverter/charger as Himcules pointed out, although some coaches have a separate converter and inverter. I am posting both charts for information purposes, and someone else may read it in the future.

Himcules · 04-29-2013, 02:22 PM

wnytaxman, what make and model is your inverter?

if you have a multi-meter, you can test on your batteries to see if you are getting a a reading of 13.5v or so, which means your batteris are being charged...

wnytaxman · 04-29-2013, 02:30 PM

I'm going to try to get down to the storage facility tonight to answer your questions. As I said, this is something totally out of my league so let me see what I can find out and then answer your questions.

ed

tmmar · 04-29-2013, 02:35 PM

Ed,
Not sure about the electrical draw but could it be that the transfer switch is where the hum is coming from? Also, I don't know if the transfer switch draws any power when it is working. Maybe someone here knows if it does.

Also, could the switch to use electric for the water heater be on?
Tom

Himcules · 04-29-2013, 02:38 PM

Quote:

Originally Posted by wnytaxman

I'm going to try to get down to the storage facility tonight to answer your questions. As I said, this is something totally out of my league so let me see what I can find out and then answer your questions.

ed

as you can see from my pictures, i still have the stock magnum 1200 watt inverter. mine makes noise as well when i am on shore power with nothing running. if your inverter was replaced with a stock unit, then it's probably the same make and model. unless you had a completely different type installed...

i do plan to rewire the coach to have all outlets inverted with a much larger inverter (long time from now when i get to dry camp a lot more). right now, it stays stock until it breaks and out of warranty.

wnytaxman · 04-30-2013, 03:11 PM

So here is where we are at the moment. FR suggested the problem may have been that the inverter was on, which would have a draw on the shore power. I checked and the inverter was not on. So far we have eliminated the block heater being on and the inverter being on.

My transfer switch is a Progressive Dynamics PD52 and I have a Magnum inverter. I don't know if that information helps, but that's what's in the bay. BTW Himcules, my power set up is much different than yours. My power cord is in a bay which contains only the power cord and teh transfer switch.

Here is the sequence of events that occur when I plug into shore power. It shows no draw on either line 1 or 2 for about 30 seconds. Then I get an immediate draw of 10 amps. After that first burst, the draw will be from 7-10 amps.

I don't know if that info helps, but that's where I'm at.

Ed

Himcules · 04-30-2013, 03:33 PM

well.. the inverter doesn't have to be on for the converter/charger portion of it to work and charge the batteries.

there is a breaker on the magnum inverter. i do not know if that cuts off everything on the inverter or just the a/c power side of it. maybe try to set that breaker off and see if the noise and draw disappears. if it does, then you know for sure it's your magnum inverter trying to charge your batteries.

rvdrmin · 05-01-2013, 10:14 AM

We have a '13 360QL with an 8K Onan generator. Recently it is shutting down when batteries reach full charge. Onan said the Magnum inverter is 'back charging' the Onan inverter tripping the shut down. Onan replaced generator inverter during my visit. It's still occurring and Magnam said they haven't had any other problems like this. Xantrex inverters did previously, according to Onan techs, but modification was made to correct the issue. For now have to run load on house batteries to insure never gets fully charged if I want to use generator. FR is going to replace my inverter, but wanted to know if any other Berkshire owners have had this problem?

Himcules · 05-01-2013, 10:27 AM

Quote:

Originally Posted by rvdrmin

We have a '13 360QL with an 8K Onan generator. Recently it is shutting down when batteries reach full charge. Onan said the Magnum inverter is 'back charging' the Onan inverter tripping the shut down. Onan replaced generator inverter during my visit. It's still occurring and Magnam said they haven't had any other problems like this. Xantrex inverters did previously, according to Onan techs, but modification was made to correct the issue. For now have to run load on house batteries to insure never gets fully charged if I want to use generator. FR is going to replace my inverter, but wanted to know if any other Berkshire owners have had this problem?

my 390bh did not come with a remote onan autostart module. only way for the generator to turn itself off is with the autostart module. perhaps there is something programmed in yours? do you happen to have the wireless onan autostart?

something doesn't sound right...

the generator does not directly charge the batteries. it uses the inverter to charge the batteries. generators are not hooked up like the vehicle's alternator where there is a direct charge. the generators produce AC power into the auto transfer switch which powers the house portion of the coach. the inverter is plugged into one of the house outlets and takes the AC power and charges the batteries and transfers its outlets over to AC as well. so the "back charging" is SUPPOSED to happen. the magnum inverter goes from bulk to float charge when the batteries are full. it does send the full signal back to the generator autostart module.

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