Bluetti Admin.
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I got myself involved in doing the 120Vac electrical wiring for an RV conversion of a cargo van.
The owner of the van has already bought a AC200MAX before asking me to wire the unit.
He only wants the 120V electrical power in the van fed from the inverter. No provisions for shore 120V power. Strictly a stand alone inverter power system…
Lighting will be 12Vdc LED.
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He has four 100W 12Vdc solar panels mounted on the roof for charging the battery inside the inverter. He will also use the Van 12Vdc system to charge the battery as well. (If needed I believe he said.) (The owner and a friend of his will be doing the 12Vdc wiring.)
His electrical drawing shows five 120V duplex outlets.
3 convenience duplex outlets.
1 for a small refrigerator.
1 for a small electric cook top.
I will install 2 wire with ground NM sheath cable, (Romex trade name), with plastic boxes for the wiring. (Meets 2020 NEC Art 551)
(Best install and supporting practices of the NM cable will be followed to eliminate any chance of cable chafing due to vibration of the moving van when being driven.)
My plan is have two circuits one 15A and one 20A, all GFCI protected. Cook top has a dedicated 20A circuit.
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MY Problem…
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From what I have read on RV forums the AC200MAX can not be wired as a Grounded System. It is factory wired SDS (Separately Derived System) Ungrounded 120Vac system. The 120Vac is “Floating above ground”. The owner manual say nothing one way or the other about wiring the Ungrounded, floating 120VAC output to meet 2020 NEC code 250.20(B) it shall be a Grounded System.
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I would not open up the inverter and make the bond internally. I know that would void the warranty.
I have read on RV forums Configuring the AC200MAX as a ground system will cause damage to the inverter. ???
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My plan is to use the NEMA TT-30, 120V/30A receptacle outlet on the inverter to feed a small 2 space/4circuit, load center, electrical panel. (I will feed the panel with a 10/3 rubber cord wired to a TT-30 125V/30A male plug.)
Note: I have read the polarity is reversed on the TT-30 receptacle on many AC200MAX inverters. I will verify/correct the polarity IF the inverter outlet is reversed. I will correct the wiring polarity at the male TT-30 plug. The correct/corrected “W” on the TT-30 inverter outlet will be the conductor I bond to the new electrical panel metal enclosure and bond to the metal chassis of the cargo van.
“W”, white conductor of the 10/3 rubber cord will connect to the neutral bar in the electrical panel. The Green bonding screw installed to bond the Floating “W” conductor to the metal enclosure of the panel. This is not a sub panel. No provisions will be made for the use of Shore Power.
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This wiring configuration makes the 120Vac output of AC200MAX inverter a Grounded System.
Meets 2020 NEC.
Do you see a problem making the floating 120Vac output of the inverter to a Grounded System?
1- Hot ungrounded conductor.
1- Grounded, Neutral, conductor.
A true common equipment safety ground plane for any metal grounded surfaces inside or outside the Van.
No chance of a Live Skin electrical shock hazard.