I am about to buy 75' of 10/4 stranded cable (Carol cable) to hook up two generators (to two different homes). Ain't screwing with two generators hooked to the same house - yet.

I will use 25' of cable to connect a 7,000 watt unit to my home, and the remaining 50' to connect a 9500 watter to the other home.

The manual on my 7,000W unit claims (note I wrote 'claims') that it will produce 57A at 120vac or 28.3A at 240vac. I will be using an L14-30P plug to pick up juice from my gen, and that connector has two 30A breakers on it.

I don't know what the amp ratings on the 9500W unit are, but they should be reasonably higher.

I just read an interesting post - "What is the amp rating for a 75' run of 10-3 romex wire?", and the conclusion was that the 10/3 (solid conductor) Romex was good for 30A max, period.

So, my questions are:
1. Will the 10/4 stranded cable support a higher amp load than the 10/3 Romex? One (me, for ex) might be inclined to think that the answer is 'Yes', mainly due to the multiple strands of wire per connector, and due to the 'skin effect'.

2. What is the max ampacity of 10/4 (or 10/3) stranded cable?

3. I think I will be OK with this cable for the 7,000W unit, but what about the 9500W unit? Maybe just a bit more voltage drop due to the longer length?

4. If both hot legs of this connection were each carrying 25A of 120vac load (no 240vac loading), wouldn't an Amp clamp read 50A on the neutral connector?

5. There will be a frame ground wire also, which will be bonded electrically with the neutral in the house panel, but in looking at the schematic for the gen I did not see any connection between gen frame ground and any neutral point in the A/C pathways.

The gen is supposed to have a frame ground wire added to either an earth ground rod or a metal water (not gas) pipe, etc.

If the neutral connection were to become open, then in spite of the frame ground connection, it would seem that no 120vac load would function at all. However, a 240vac load should work normally.

Is this correct?

Please advise asap.

Many thanks

Fred
N4HMR

Fred,
A few questions for you...
Do you own both of the properties?
Are you a licensed electrician?
Are you applying for permits?
Do you have an electrical code book? (are you in the USA?)

H. F. -

1. I own only the house using the 7,000W unit (gen capability 30A at 240vac). I could easily use a 6' length of cable if the gen were placed directly below the power panel (outside), or a 20' run if the gen was placed inside a shop building right behind the panel. Just a small hassle getting the gen into and out of the shop.

The other user is not an electrician, but says an 'electrician' told him 10/3 would be adequate for his purposes - 50' of cable coming off a gen with estimated 240vac 40A breakers. However, I am beginning to seriously question that at this point. Note: He would be handling the install, not me.


2. No, I am not licensed, but have worked with an electrician for some 6-8 months in the past - general house wiring. I do have an electrical/electronic background through my work, though, so know enough to ask a bunch of questions..

3. Nope. See #1.

4. Unfortunately, 'No' on the code book.

Fred

With respect to your original question: there are many kinds of cord although most common will have an insulation rating of 300 volts and ampacity equal to or less than #10 solid copper... tell me the specific cord and I'll tell you the specific ampacity.

If you're not sure about this you should hire professional help...

I just got this info from the guy that has it - P136-29 MSHA 10/4 SOOW 90 Degree 600V .
He told me it was Carol cable.

But when I called General Cable (they make the Carol brand), the Gen Cable Rep said the P136-29 number was registered to Belden as one of their MSHA (Mine Safety and Health Administration) numbers.

Crap, am I going to have to dig a hole to use this Dang cable?? Yuk yuk!

NEC Article 400(A)(1)... 25 amperes max
This cable cannot be direct buried...