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mdbaggs · 07-18-2012, 08:02 PM

Took the rig for service which included a recall on a specific breaker I guess. They installed a new 30A breaker that supplies my main aux(house) inverter. Got the coach back and now after running the coach off of shore (15A at my home) or off of the generator the entire house is losing power. Everything shuts down 100% even with a minimal load, but no breakers trip. I stood at the inverters and when this happens one seems to shut down first (I'm not sure which is the house inverter and which is for the residential fridge, but suspect the house inverter is the one that is going off first.). That inverter then seems to try to restart makes a few clicking noises, but no power comes back on. Starting the engine after a complete house power loss somehow causes a reboot and the house power comes back temporarily, but will shut down again after anywhere from 15-20 seconds or up to several (5-10 min).
I don't really trust this dealer that did the work. I pulled the suspect breaker and its dated Mar, '11. I don't know where they got it from because they initially claimed they didn't have any replacements and it isn't obviously brand new. I can't help but wonder if they didn't pull it out of a scrap box... Anyway, can I replace this 30 A Murray, Model MP130 60 Hz, 120/240V, 1 pole breaker with breaker from Home Depot, etc. or is there something special about it?
P.S. I am desperate as our main annual family vacation is supposed to begin on the 25th. This has to be fixed

J Birder · 07-18-2012, 08:21 PM

It should be a standard household type breaker.

Joel

JimM68 · 07-18-2012, 08:31 PM

You can replace it with any household 30 amp breaker that will fit in the box. Different brands use different mounting sometimes.

I'm wondering though, if they simply let your batteries run down, and your charger is sucking more amps than your 15 amp hookup can provide? That would result in low shore power voltage to the rig, which could cause things to brown out and/or shut down.

My magnum (2000 watt inverter / 100 amp charger) draws a bunch of juice when charging at 100 amps. On my home 20 amp hookup, I cannot run anything else until the batteries come up and the charger goes down to 50 amps or so.

mdbaggs · 07-18-2012, 09:07 PM

JimM, I think I follow what you are saying, but it wouldn't reason as my batteries are fully charged on the coach and the chassis. As well it is doing the same thing, shutting down 100% when the generator is running 66A into the coach.
I also see that the breaker says it is a Type MP-T Interrupting.
I wish I would have learned more about electricity than my college phyisics taught me 20 yrs ago. Learn as you go I guess.
I also see that the breaker says it is a Type MP-T Interrupting. What that means , I don't know yet. Maybe JBirder or somebody else can educate me.
Thanks for the replies so far.

RV Wizard · 07-19-2012, 02:38 AM

If the battery bank voltage drops too low the inverter will drop out any attempts to charging or inverting power as an overload. Starting the drive engine starts charging the house batteries and the inverter may start a little longer charger or inverter on time.

I would recommend you get the battery bank charged up fairly well and then energize power to the coach. Turn the house inverter off. If you only have power to the microwave and duplex receptacles when the inverter is on you need to check the circuit breakers on the inverter. If they are not tripped you have an internal problem with the transfer switch in the inverter. If you have a Zantrex you might want to see if the fuse on the inverter's control board is blown. What may be happening is that you have 120 vac feeding the inverter that would normally pass thru when you have shore or generator power and the charging section of the inverter is powered up and charging your batteries. If the voltage is not passed thru then the inverter thinks it need to invert power from the battery bank.
Good luck, stay safe and keep us posted.

wa8yxm · 07-19-2012, 06:51 AM

Nothing special about the 120 volt breakers in most RV's. Though I have seen some "Strange" breakers in parks, never seen an odd one in an RV.. Take the breaker you have now to Lowes or Home Depot or Joe's Hardware (Generic name) or Sam's Electrical supply.

However, You said: "Everything shuts down 100% even with a minimal load, but no breakers trip."

If the breaker is not tripping then it's not the problem.
"
IF the inverters are shutting down, Then either the new breaker was installed wrong (Odds of that happening approach ZERO) Or you have a 12 volt side of life issue, Dead (low) batteries, or dirty connections.

mdbaggs · 07-20-2012, 10:07 PM

Wa8xymn hit the nail on the head. Bad 12v battery bank on the house side. It only took the technician 5 hrs yesterday to find nothing, 2 hours today with my assistance to identify the problem replace the 4 6V batteries. Then it took another 4-5 hours to look for other causes that it still wasn't working to finally get a more seasoned tech to go through it only to find that the less experienced tech hadn't hooked up the batteries correctly. Then, presto, -$750 labor, -$400 batteries, problem fixed. I still sort of feel like I got shafted even though they only charged me for about 1/2 the time they put into it. Funny, I even told my DW, it was probably the batteries. Also, first thing I asked them this morning was did you check the batteries they claimed yes

Live and learn...... Sure can be expensive, but hey at least we will be on vacation really soon.
Thanks all.