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Re: Looking for the reason - Charger breaker tripped?

Reply #25 – December 16, 2013, 05:56:16 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.

Update:  After speaking with the Tech at Magnum and me explaining what has been happening with the breaker tripping, he feels that the (6/2G) wire from the Main Circuit Breaker Box and the Circuit #8 wire are in the incorrect position in the Switching Relay #2.  In the current wiring all coach power would go through Circuit #8.  He has suggested that I swap positions on the Swithcing Relay #2.  He futrther suggested I get my multimeter and by measuring the inputs I should be able to determin the actual wiring.  I believe he said that the inverter/converter will have the same reading both input and output whereas the input and output from the pedestal will be somewhat different.

So.......All of you electrical guys out there - Does this make sense to you?  And if it does, I should be able to exchange input positions on the Switching Relay #2 and eliminate this tripping issue.

By the way re:  Changing the breaker from a 20amp to 30 amp for Breaker #8.  - Is not a good idea unless the (12/2G) wire from breaker #8 is increased to accept the load.  Of course he said this before we started talking about which power leg goes into the Switching Relay #2 from the Main Circuit Breaker Box and inverter converter.

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Re: Looking for the reason - Charger breaker tripped?

Reply #26 – December 16, 2013, 06:22:03 pm

Scott,

Part of the answer will depend on actual location of the components.  If that 6-2 wire from main breaker box to second ATS could be used to provide power IN to the inverter/charger, likely using a 30 amp breaker, then the inverter/charger's internal ATS could be used and remove the secondary ATS.  The sub-panel could be wired from the inverter/charger 120 VAC output.

Bottom line, unless you will be running enough different appliances to exceed the inverter's capacity, I see no reason for a secondary ATS.  If you might exceed the inverter's capacity, I would run heavier wire from main breaker box to inverter IN and use a 30 amp breaker.  Then inverter OUT to ATS.  But, make sure that the "favored" position for the secondary ATS is shore power!

Brett

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Re: Looking for the reason - Charger breaker tripped?

Reply #27 – December 16, 2013, 06:37:33 pm

Brett - Wouldn't it be easier/better to flip the wire position going into the ATS?

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Re: Looking for the reason - Charger breaker tripped?

Reply #28 – December 16, 2013, 07:35:04 pm

If you mean wire shore power as priority, yes, you can do that.

But, not sure I understand the reason for an additional ATS (second one in addition to the one built into your inverter/charger).

You should still use heavier wire and breaker to supply the inverter/charger (to feed the charger section-- you don't want to be within 2 amps of capacity) and verify with Magnum that they have no problem having 120 VAC in, but not supplying sub-panel from inverter unless shore power is off.

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Re: Looking for the reason - Charger breaker tripped?

Reply #29 – December 16, 2013, 09:42:37 pm

Brett - Good point. 

So are you saying I could run 6/2G wire from the Main Breaker into inverter/converter power and take Inverter Output directly to Circuit Breaker Box #2.  OR  Leave wiring the way it is and just replace Breaker #8 with a 30amp and change Circuit #8 from 12/2G to 10/2G making sure that the 6/2G wire (Pedestal) be placed on the Primary?

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Re: Looking for the reason - Charger breaker tripped?

Reply #30 – December 16, 2013, 09:53:26 pm

Yes, either option would work.

But, having the extra ATS just adds one more item which can fail.  The only reason for the second ATS is that you want to be able to run things powered by the sub-panel that exceed the capacity of the inverter and its internal transfer switch.  If not, remove one piece of complexity.

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Re: Looking for the reason - Charger breaker tripped?

Reply #31 – December 16, 2013, 10:03:23 pm

Brett -

What you said is a mouth full.  Don't know if I'm comfortable bypassing the #2 ATS.  HMMMMMMMMMM.

I have sent and email to Magnum requesting input regarding bypassing Switching Relay #2.

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Re: Looking for the reason - Charger breaker tripped?

Reply #32 – December 17, 2013, 11:54:46 am

Hi Scott
When I talked to James Triana at FOT he said that as originally wired, the secondary transfer switch gives shore power priority. With 50 amp to the secondary transfer switch, then to the inverter sub panel, you have plenty of power for the three 20 amp circuits on the inverter sub panel. Provides for those of us who might be using microwave, toaster, coffee maker, electric grill, etc when on shore power.

If the secondary transfer switch fails, it could block shore power but pass power from the inverter. James opines this could be what happened. If so, the inverter would still pass shore power from circuit 8 (charger) to the transfer switch, then to the inverter sub panel. This would leave you with a 20 amp circuit from the main panel feeding the three 20 amp circuits in the inverter sub panel. Easy to see how the breaker would trip.

In our coach both breaker panels and both transfer switches are under the bed. The inverter is about 20 ft forward. Replacing the secondary transfer switch requires removing the primary transfer switch and the surge arrester/ems and the secondary transfer switch, then reinstalling all three. Pulling new wire to and from the inverter would give me up to 60 amp pass through (inverter pass through limit) but that's a lot of wire and I'm no electrician. I don't see any attractive options.

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Re: Looking for the reason - Charger breaker tripped?

Reply #33 – December 17, 2013, 12:52:18 pm

Got a response for Magnum thea AM.  Is as follows:

"You could do that but you will need to move the 6/2G wire from the main buss in the main panel to thirty amp breaker or wire the inverter for single in single out 60 amp and change the wire on the output of the inverter to 6/2G also. This is because the 6/2G there now is protected by a 50 amp breaker and all wire must be sized for that size overcurrent protection. FYI I would probably do this if it was my installation, one less failure point."

I will review the schematic and try to digest what he suggested.  Will probably follow Brett's and Magnum's suggestion once I figgure out HOW to do it. 

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