Portable Generator Max Ampacity and Cord Size

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marmathsen

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Location
Seattle, Washington ...ish
Occupation
Electrical Contractor
I'm looking at setting up yet another portable generator inlet for a single family residence. I'm hoping to get corrected on the following if anyone feels I'm off base.

My experience in the past has just been to setup an L14-30R inlet and the customer supplies their own generator and cord. I advise them on the bonding requirements.

The generator this current customer is looking at has a locking 30A locking receptacle but it also has a 14-50R (non-locking). It maxes out at 9500W (12000 peak). It seems odd that the 50A is straight blade but I can't find anything in the manual that implies the 50A should be treated differently from the locking 30A and wouldn't also work to supply power to a home (anyone disagree?). So I'm inclined to setup a Reliance PB50 which has a NEMA CS63-65 50A locking receptacle.

They asked that I make a 50' cord set (I don't typically do this). Based on 400.5, I'm inclined to use 4AWG SOOW because of the fact that it will be in direct sunlight in the afternoon, 50' is a modestly length for an extension cord and 445.13 requires generator conductors to be rated at 115% (although I don't think this technically applies because it's protected by a 50A breaker on the generator). I'm assuming the requirements of 445.13 supersede the continuous load requirements of 220 and that I don't need to size it at 125%...right? Although I suspect I might be told that this portable cord set is outside of the purview of the NEC.

Here's the generator manual if anyone is interested https://cdn.shopify.com/s/files/1/0052/1276/6281/files/XP12000EH_manual.pdf

Thanks in advance for any input.
 
I would almost bet they can buy the cord cheaper than they can pay you to make it.
And it's a factory made and sealed cord.
But finding it with straight blade on one end and locking on the other may prove hard to find.
No. You're right the 115% does not apply.
 
I strongly recommend a whole-panel interlock instead of a small few-circuits panel.

Those cords are common, and you can buy one for less than you can buy the parts.
 
LarryFine said:
I strongly recommend a whole-panel interlock instead of a small few-circuits panel.

Those cords are common, and you can buy one for less than you can buy the parts.
Click to expand...
And the interlock kit is way less labor and money.
Also I looked at the schematic and I didn't see a neutral to ground bond.
 
A pre-terminated cord can be had at any RV store, Camping Theives (World), or other RV repair facilities. You can even get one that has the straight blade on one end, and put your own twist lock on the other.
 
I went through the same scenario a while back. You can certainly buy the cords to almost any length a lot cheaper than you can make one. You can get them with 50A cord caps as well.
I found mine on Amazon. Just search generator cords.
 
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