Looking for the reason - Charger breaker tripped?

Topic: Looking for the reason - Charger breaker tripped? (Read 1276 times) previous topic - next topic

Looking for the reason - Charger breaker tripped?

November 20, 2013, 09:20:12 pm

Hi Folks-
This has not happened often. The last time it happened the breaker was the last thing we checked and we ran the house batteries down to nothing. Tonight while making dinner the Charger breaker tripped under the bed. Electric grill, Microwave and AC Aquahot were on as well as some lights and the TV. We are plugged into a 50 amp pedestal. This has occurred before but I did not link the three high watt usage devices to the breaker tripping until tonight. Can any of you electrical people share with me what occurred? I presume we were using more amps than were available but why did the Charger Breaker trip? I know - Energy Management.

Still learning.

Thanks in advance for your comments.

Re: Looking for the reason - Charger breaker tripped?

Reply #1 – November 20, 2013, 09:36:18 pm

It may only be that the breaker that tripped is weak and needs to be replaced.Gam

Re: Looking for the reason - Charger breaker tripped?

Reply #2 – November 20, 2013, 09:37:14 pm

Will have to make some assumptions on this, as there is some variation in both chargers and in wiring.

Assuming that the breaker that tripped is the breaker in the main breaker panel that supplies your INVERTER/charger (all that assumed), the explanation is as you said-- your total draw exceeded the breaker's rating.

The breaker supplies 120 VAC to the inverter/charger. The inverter/charger either has a built in transfer switch (often called pass through) or you have a separate ATS (Automatic Transfer Switch). If the breaker supplying 120 VAC trips, then the inverter automatically switches from passing through the shore power to supplying those circuits downstream of the inverter by "inverting" from the battery. Again, large 120 VAC loads supplied by the inverter will discharge the battery bank rather quickly.

If this is not how your coach is set up, let us know and we can go from there.

Re: Looking for the reason - Charger breaker tripped?

Reply #3 – November 20, 2013, 09:54:30 pm

Thanks Gam and Brett.

The breaker that tripped is the breaker in the main breaker panel under the bed mounted on the platform.

We have a Magnum 2820 INVERTER/charger and 2 Automatic transfer switches. One under the bed and the other is in the basement.

Sooooo...Because I am attempting to draw more amps than the breaker is rated for, it trips?

Re: Looking for the reason - Charger breaker tripped?

Reply #4 – November 20, 2013, 10:01:52 pm

Yes.

And, if the inverter is rated for more amps/watts than is the breaker, it may be able to supply those heavy loads, but will certainly take a lot out of the batteries.

What is the amp rating of the breaker? Have you added up the amp draw of the various loads you were running? Be sure to include some for the inverter/charger charging the batteries unless you have been on shore power for a couple of hours (so charge rate will have diminished).

BTW, many inverter chargers allow you to limit the amps used for charging the batteries to leave more amps to power other things in the coach. I know on the Xantrex products it is call "power share" and is programmable.

Re: Looking for the reason - Charger breaker tripped?

Reply #5 – November 20, 2013, 10:20:38 pm

Brett the breaker is 20 amps. Our Magnum is rated at 2800 watts. The Prosine we replaced was rated at 2000 watts.

Aquahot - 1500 watts, Microwave - 1100 watts, Electric grill - 1500 watts, then some watts for lights and TV. We have been plugged in for days.

Soooo.. all incoming 50 amps is going through a 20 amp breaker and into the INVERTER/charger?

I do not know if the Magnum has Power Share. I will find out but since we have been plugged in the draw should be minimal.

Brett - How did you learn this stuff? What book should I get to read about how this stuff works in this practical application??

Re: Looking for the reason - Charger breaker tripped?

Reply #6 – November 20, 2013, 10:30:03 pm

With the microwave and the grill you were pulling roughly 25 amps plus whatever the inverter was pulling to charge the batteries, so this would trip the 20 amp breaker.

Re: Looking for the reason - Charger breaker tripped?

Reply #7 – November 21, 2013, 08:30:59 am

Quote from: Carol & Scott – November 20, 2013, 10:20:38 pm

Soooo.. all incoming 50 amps is going through a 20 amp breaker and into the INVERTER/charger?

Brett - How did you learn this stuff?

No, only power to those circuits that can be powered by the inverter. Said another way, only those 120 VAC circuits that still work with shore power disconnected and generator off. I would be surprised if aqua-hot, roof A/C's, etc went through the inverter.

Learn by a lifetime of doing it. Worked my way through school turning wrenches on VW's, then did all the work on my off shore sailboats, now RV's.

Re: Looking for the reason - Charger breaker tripped?

Reply #8 – November 21, 2013, 09:51:08 am

I guess I am apprenticing now. Some day when I grow up I might know how this stuff works. Thanks for the help.

Re: Looking for the reason - Charger breaker tripped?

Reply #9 – November 21, 2013, 10:04:13 am

"Learn by a lifetime of doing it." That's the best way. Of course, it helps if there is someone there to stop me before I make a stupid mistake. One example: when I was in high school we finished the basement. One of the smaller parts in that project was to put in three-way switches at the top and bottom of the stairs. We got the new switch installed and were connecting the wires at the old switch when sparks started flying. Dad turned to me and said "I thought you took out the fuse." I replied "I thought YOU took it out." We both went downstairs and took out the fuse. Fortunately neither one of us was hurt, but since that time I always disconnect the power as far up line as I can before I do anything.

Re: Looking for the reason - Charger breaker tripped?

Reply #10 – November 21, 2013, 08:17:07 pm

I usually work on a live circuit, it keeps me focused...

I knew an old electrician once who checked for voltage by touching with his fingers...

Re: Looking for the reason - Charger breaker tripped?

Reply #11 – November 21, 2013, 09:14:49 pm

If I could just master these computers. The software just kills me. I still have not gotten the retarder temp to work on my vmspc. My wife has to rescue me all the time. If computers only needed large wrenches and hammers, maybe I would be more successful.

Re: Looking for the reason - Charger breaker tripped?

Reply #12 – November 22, 2013, 11:23:03 am

Peter,
When I was in the Navy I worked on A7-E Coursair radars. We would test to see if it was transmitting by standing next to it while sweeping and putting our hand in front of it to see if we felt the heat on our hand. Crazy huh.

Mark

Re: Looking for the reason - Charger breaker tripped?

Reply #13 – December 05, 2013, 09:54:39 am

We have the same inverter (Magnum MS2812) and the same problem (breaker 8 - charger trips, kills all the inverter pass through circuits). Ridiculous, the inverter has 7200 watts pass through capability, should not be controlled by a 20 amp breaker. The pass through circuits are supposed to be controlled by the 50amp main on the inverter sub-panel.

Talked to James Triana, said he couldn't help much as he isn't familiar with the Magnum inverters, they don't use them. He thought it sounded as if the secondary transfer switch had been bypassed. He did send me the appropriate schematic, we had none with the coach.

The schematic shows circuit 8 (charger) goes from the main panel to the inverter to power the charger/converter. The pass through circuits go from the main panel to the secondary transfer switch. Struggling through the Magnum inverter manual, appears the Magnum has an internal transfer switch. Guess this would eliminate the need for the secondary transfer switch Foretravel originally installed. Seems this would also mean the pass through circuits should be wired directly from the main panel to the Magnum inverter (and circuit 8 charger eliminated).

MOT installed this inverter in 2012 when we bought the coach. Headed there next month for other repairs, will have them go through this. Will also talk to the folks at Magnum. If anyone has installed this inverter in a coach with two transfer switches, and solved the pass through problem, would like to hear how the wiring was done. Sounds like a major problem if a residential refer has been added to the inverter pass through circuits.

Re: Looking for the reason - Charger breaker tripped?

Reply #14 – December 05, 2013, 11:55:01 am

Mike,

Not sure I have a clear picture of how yours is wired, but many, many inverter/chargers have internal transfer switches.

And, it is common to wire from main breaker box breaker to inverter IN and inverter OUT to sub-panel powering only those things you want to be able to power from the inverter. The line from main breaker box also supplies the charger section of the inverter/charger.

What are you running that takes more than 20 amps total and is therefore tripping the 20 amp breaker. If batteries are deeply discharged (and therefore the charger section is taking a lot of amps), most inverter/chargers have a feature called "power save" or "power share" that allows you to restrict the amps the charger section uses. On ours, the default setting (amps to be able to be used by charger section) is 30 amps. I have it set to 10 amps, and there is a 5 amp setting. That will certainly allow you more power for your other items.

Brett

Re: Looking for the reason - Charger breaker tripped?

Reply #15 – December 05, 2013, 03:53:23 pm

Brett
We were plugged in to 50amp shorepower for about two weeks before this happened. Can't see how the charger would have been pulling much but admit had not been checking. On Thanksgiving we had a turkey cooking in the convection oven, dressing baking in a toaster oven plugged in at the buffet in the kitchen. After about 45 minutes cooking, the coach interior lights dimmed, then came back up. Checked and found all circuits were working but we had been switched to inverting from the batteries. The batteries clearly couldn't maintain that much load for long so we switched to plan "b".

I've attached a pdf of the wiring as it came from the factory. Also a doc file of what's in our main breaker panel and the inverter sub-panel.

Thanks for your thoughts.

Re: Looking for the reason - Charger breaker tripped?

Reply #16 – December 05, 2013, 04:05:01 pm

Yes, that clearly shows that there is a separate ATS. Wiring shows 6/2 from main breaker box to this secondary ATS and from the ATS onward. So, yes, the breaker in the main box can certainly be larger than 20 amps assuming the diagram does reflect what you have.

As always when working with electricity, least strong element dictates capacity.

Re: Looking for the reason - Charger breaker tripped?

Reply #17 – December 05, 2013, 04:09:42 pm

Mike I am glad that you are dogging this down. Sounds just like our situation. We have been watching our power usage and making adjustments to avoid this situation. It is crazy to me that this is occuring but I have greater issues on which to work today. Also thank you for the attachments. I will copy and file in my U320 file.

Thanks again,

Scott

Re: Looking for the reason - Charger breaker tripped?

Reply #18 – December 05, 2013, 09:09:03 pm

You might check the magnum inverter. Some of them had 2 inputs and 2 outputs. If they are wired together that could cause the inverter to pull more power than a 20 amp breaker could handle. If that is the case the charger circuit could go to one input and the other circuit breaker could go to the other input. However with a microwave on and a toaster oven on that would overload a 20 amp breaker.

Re: Looking for the reason - Charger breaker tripped?

Reply #19 – December 13, 2013, 07:39:30 pm

I called Magnum. The tech verified the charger and inverter were both working. Referred me back to the chassis builder, had no idea how a two transfer switch system would work. Talked to James Triana at FOT. He sent me the appropriate pdf, said FOT doesn't use Magnum inverters, wasn't sure where to point me.

Went through the pdf of the inverter electric from FOT, tried various combinations of inverter, charger, and circuit 8 shore power on and off. Called James Triana back with results of my trials. He thought it sounded as if the secondary transfer switch has failed. This switch has two inputs, a 50amp 6g line from the main panel, and a 30amp 10g line from the inverter.If this switch failed and would pass 120v from the inverter, but not from the main panel, would explain everything.

I'm going to assume this is the problem, will post back to this thread if this solves the problem. Will start a new thread seeking help on the switch replacement.

Re: Looking for the reason - Charger breaker tripped?

Reply #20 – December 13, 2013, 10:49:42 pm

Can't help with your secondary transfer switch replacement, but I moved the microwave circuit from the inverter output to its own breaker on the primary panel when we had our old Xantrex inverter charger. We never run the microwave off the batteries, and having it on its own circuit meant we didn't have to juggle toaster and microwave use on the Xantrex 30 amp pass through to the secondary panel.

We now have a Magnum, (the 2KW version MS-2012), and its internal transfer switch works fine, but our coach didn't come with a secondary external transfer switch.

Just checked the Magnum manual, and for MS2012 and MS2812, the maximum feeding breaker size for "single-in / single-out" configuration is 60 amps or the max the RV primary panel is wired for. The feeding breaker for ours is 50 amps. If you change the feed breaker to 50amps, you may solve your immediate problem. The max pass-through is 60 amps according to the manual, so the internal transfer switch should be fine.

Re: Looking for the reason - Charger breaker tripped?

Reply #21 – December 14, 2013, 10:32:26 am

Hi Dave - Hope all is well with you guys.

Based on the table copied from the PDF above our microwave is on a separate breaker on the Inverter sub panel and the 20 amp Battery charger is on the main panel. Am I correct to assume that all of the Inverter sub panel power comes from the 20 amp Battery charger breaker?

Inquiring minds whish to know. :-)

Electrical Panels
Mains
   50
   50
3.    Refer, line monitor, vacuum, freezer      20
4.     Rear roof AC                 20
6.    Aquahot                 20
7.    Hot water dispenser              20
8.    Battery charger              20
9.    Engine heater, line monitor         20
10.    Front roof AC                 20
11.    Blank                    20
12.    Washer Dryer                 20
14.    Middle roof AC (option 4200)        20

Inverter sub panel

Main
   50
1. Ice maker, TV, VCR, Sat, Bose, Dash, Bedroom   20
2. Microwave                    20
5. Fan, stove, line monitor, TV, bath, kitchen   20

Re: Looking for the reason - Charger breaker tripped?

Reply #22 – December 14, 2013, 11:05:30 am

Morninghill - Good day. I have taken the liberty of sending your above attachement to Magnum requesting assistance re: Charger Breaker tripping.

Re: Looking for the reason - Charger breaker tripped?

Reply #23 – December 15, 2013, 01:57:57 am

Yes on ours, all the power for the inverter/charger (now Magnum) comes through the 50 amp breaker on the main panel. All of the sub panel is fed from the 120V output from the Magnum inverter/charger. So if we're running on inverter, the max is 30 amps@120V (for a short time...), and when on shore power, the transfer switch in the Magnum is passing up to 50 amps from our main panel, and the max combined power output from the sub panel is therefore 50 amps.

Re: Looking for the reason - Charger breaker tripped?

Reply #24 – December 16, 2013, 05:11:43 pm

Sent wiring diagram to Magnum for their review and breaker assignment by box. Their Tech guy suggested I put a 30 Amp breaker in that circuit as the inverter/charger will use 18 amps at full charge rate and only leave 2 amps for pass through. He also noted: that I "have a bypass transfer switch on the output but he wasn't sure which position is priority".

? Waiting for a call back to clarify.

Affiliate Notice