Note: My area of NEC expertise is in Industrial power/controls This is a "government job, obviously" I am not a DIY installer normally.
I am installing an 1800 watt true sine wave inverter in my existing motor home. I have sized the DC feeder and class T fuse (no problems). I am in the process of designing the branch circuit protection/sub-panel.
I have a question RE: NEC 551-40 (c) "Ground Fault Cicuit-Interrupter Protection" (From 1999 NEC, yes I just ordered a current copy)
It states which receptacles must be protected and the existing receptacles meet the requirements. My question arises from reading the installation instructions from the Vendor, i.e. do I need protection of all receptacles on each branch circuit? (I think not)
Excerpt from Vendor supplied installation manual.
2.4.3 Ground Fault Circuit Interrupters (GFCIs)
Installations in Recreational Vehicles (for North
American approvals) will require GFCI protection of
all branch circuits connected to the AC output of the
hardwire terminal equipped Sine Wave Inverters. In
addition, electrical codes require GFCI protection of
certain receptacles in residential installations. While the
true sine wave output of the Sine Wave Inverter is
equivalent to the waveform provided by utilities,
compliance with UL standards requires us to test and
recommend specific GFCIs.
Xantrex has tested the following GFCI-protected 15 A
receptacles and found that they functioned properly
when connected to the AC output of the inverter:
End of Excerpt
If I do need GFCI protection on all outlets on each branch circuit, could I provide it with a panel mounted GFCI Breaker (e.g. QO GFCI 15 amp)? Also, then how do I indicate that all outlets are covered? (Placard at each?)
I apologize in advance if this is covered in the new code book but I am under a "time-crunch" here. Trying to get ready for our summer trip starting in 2 weeks.
I am installing an 1800 watt true sine wave inverter in my existing motor home. I have sized the DC feeder and class T fuse (no problems). I am in the process of designing the branch circuit protection/sub-panel.
I have a question RE: NEC 551-40 (c) "Ground Fault Cicuit-Interrupter Protection" (From 1999 NEC, yes I just ordered a current copy)
It states which receptacles must be protected and the existing receptacles meet the requirements. My question arises from reading the installation instructions from the Vendor, i.e. do I need protection of all receptacles on each branch circuit? (I think not)
Excerpt from Vendor supplied installation manual.
2.4.3 Ground Fault Circuit Interrupters (GFCIs)
Installations in Recreational Vehicles (for North
American approvals) will require GFCI protection of
all branch circuits connected to the AC output of the
hardwire terminal equipped Sine Wave Inverters. In
addition, electrical codes require GFCI protection of
certain receptacles in residential installations. While the
true sine wave output of the Sine Wave Inverter is
equivalent to the waveform provided by utilities,
compliance with UL standards requires us to test and
recommend specific GFCIs.
Xantrex has tested the following GFCI-protected 15 A
receptacles and found that they functioned properly
when connected to the AC output of the inverter:
End of Excerpt
If I do need GFCI protection on all outlets on each branch circuit, could I provide it with a panel mounted GFCI Breaker (e.g. QO GFCI 15 amp)? Also, then how do I indicate that all outlets are covered? (Placard at each?)
I apologize in advance if this is covered in the new code book but I am under a "time-crunch" here. Trying to get ready for our summer trip starting in 2 weeks.
Last edited:
