Wire Source to 60A service?

[USAMilRet]

I am looking for about 60 feet of wire to connect my MEP803A to my service panel.

I figure I need 3 wires of 4awg and 1 of 6 awg (ground) or 4/4 awg for a 60 amp capable tie in. I think it is less expensive to run solid copper single strand than THHN 4/4 braided. If I run either, I am going to conduit it so I think single solid copper is better than stranded for cost but stranded is better for current capacities.

So I am looking for a source that won't empty my wallet at $4 foot ($240 for 60' of 4/4 THHN).

Where does one get wire to hook up their gensets to their electric service panel for a reasonable cost? Times like this I wish I knew an electrician or someone that could get me wire at just above cost.

 

[DieselAddict]

Have you gone by your local big box home store to see what they have on the "by the foot" wall? I don't recall #4 being that costly.

Since this is underground make sure the wire is rated THWN. THHN isn't rated for underground applications. Most wire these days are rated for both but its good to check to be sure.

 

[USAMilRet]

Have you gone by your local big box home store to see what they have on the "by the foot" wall? I don't recall #4 being that costly.

Since this is underground make sure the wire is rated THWN. THHN isn't rated for underground applications. Most wire these days are rated for both but its good to check to be sure.

Not even in a conduit?

 

[USAMilRet]

I could do 4 strands 6 awg of THHN in a buried conduit if legal.

 

[DieselAddict]

THHN is not rated for wet locations. THWN is the correct wire for wet locations. Underground conduit is considered a wet location.

 

[gatorbob]

Agreed that if your local Home Depot or Lowes can sell you the THWN by the foot, that ends up being cheaper and it's likely Southwire which is easier to pull. I have used wireandcableyourway.com for cabling I can't buy locally but the brands they use are not always that great.

You'll find some cables dual rated as THHN/THWN-2 (W = wet locations). That should go in conduit and if I were going through the pain of digging a long ditch it would be schedule 80 conduit. I don't know that I would run 4/4 SER in a conduit unless I had to. SER is likely harder to pull unless your conduit size is much larger. Even with SER, make sure you have THWN-2 or XHHW-2 conductors inside. I'd go with 4 conductors of THWN-2.

I didn't know they made solid copper at 4 AWG. Might be harder to pull but I'll admit I'm not the most skilled at pulling the more complicated runs.

To save money, if you have a long run you could go Al and use a UL listed device to transition to copper, if that's even required. AL would save money and it's still used in lots of applications for ranges, dryers, etc... Some No-ox and you're fine. Your breaker is probably rated for both Al and Cu (but check). I have no idea if the MEP terminals are rated for Al. The key is to avoid connecting Al to anything that is not rated for Al or directly to copper where you end up with galvanic corrosion. There's plenty of disconnect boxes or splice kits to transition if needed.

[Edit: the SEU feeder from your utility meter is likely aluminum as well]

 

[Scrounger]

Some years ago, when I was in the electrical trade we would have to run cable underground in conduit. One crews job was only conduit installation. Then others would pull the cable and do the tie in. Not always, but quite often we would have to blow or vacuum the water out of a conduit before pulling the cable. All it takes is one bad joint to allow water in.


So, yes underground, even in conduit is considered a wet location. Ask yourself this. How much does it cost to do it right as to doing it subpar? Then ask what it will cost in the future to fix what may be damaged for going cheap now. The saying “pay now or pay later” comes to mind.

 

[pjwest03]

Around my area the electricians call it "trailer wire" the industry calls it Mobile Home Feeder Wire (MHF). It's aluminum service entrance cable with 4 conductors of 2-2-4-6. Generally its going to be the most economical.

 

[tobyS]

You would have less voltage drop and it would be cheaper with underground aluminum triplex. I just looked and a direct burial 2-2-2 was just over a $1 (some have with ground, some you need separate ground) for three wires (triplex). The only reason for going to larger wire is that it's used for branches and a common size for underground (100A). You can reduce the size by a few strands at the lug if it's too tight, you still have more cross section area than going to #6. Use plenty of anti-corrosion + tighten joints 4 times each.

Modern lugs at both ends are nearly all rated for copper and aluminum.

Edit....I see the joint at the gen set will be copper....that would have to be dealt with. I'd either change the lug out or use the pin adapter.

https://www.klauke.com/electrical/technical-reports/connecting-aluminium-and-copper/

 

[gatorbob]

You would have less voltage drop and it would be cheaper with underground aluminum triplex. I just looked and a direct burial 2-2-2 was just over a $1 (some have with ground, some you need separate ground) for three wires (triplex). The only reason for going to larger wire is that it's used for branches and a common size for underground (100A). You can reduce the size by a few strands at the lug if it's too tight, you still have more cross section area than going to #6. Use plenty of anti-corrosion + tighten joints 4 times each.

Modern lugs at both ends are nearly all rated for copper and aluminum.

Edit....I see the joint at the gen set will be copper....that would have to be dealt with. I'd either change the lug out or use the pin adapter.

https://www.klauke.com/electrical/technical-reports/connecting-aluminium-and-copper/

That's a great price. I think PVC conduit should go 18" and DB needs 24". If you're renting a trencher, it won't make a difference. I would put a run of caution tape at 6" and 18" depth and sand directly on top of the cable.

 

[tobyS]

Here are a couple sources of 2-2-2-4 al.

https://www.wireandcableyourway.com...MInai5lsD02wIVgh9pCh3glg-IEAAYASAAEgK7fPD_BwE

https://www.homedepot.com/b/Electrical-Wire-Service-Entrance-Wire/N-5yc1vZc578


Buy a bit extra....don't run yourself short.

We use this type wire for 480/3 phase instigators at 100 hp a couple thousand feet out.

 

[USAMilRet]

All great advice. I see that 6awg at some places is rated at 50A and others 55A. Want to stay away from aluminum wire. Ripped it out of my 220V house wiring and rewired with copper.

I looked at the many different types of wiring vs cost vs direct placement vs above ground. Of course the final wire size is going to be based on the total available output of the genset.

So it could be 6 awg (doubtful), 4 awg (probable). I have always found the big boxes more expensive than on line, even with the 10% discount.

 

[69birdman]

My search for 6ga wire at big box store turned up nil. I found a mom & pop electric supply store near me had 6ga thhn/thwn @ .57 per foot.

 

[USAMilRet]

Nice find.

I read up on the types and see that Type W is rated at 65 Amps for 8awg at a cost of $3/ft for 8/4. This will also allow the cable to travel with the genset for whatever reason...... Maybe the next owners won't want it......

Considering where the genset is being placed, an on the ground Type W is a good choice for me. It also keeps with the KISS principle.

 

[DieselAddict]

8 GA type W will be good for a very short run only. If you are running 50' to 100' you should use 6 GA.

 

[gatorbob]

I used the Type W as well. It's heavy duty for sure. My 6 AWG 4 conductor fits nicely in the MEP-803A wiring hole as well. I think I used some duct seal around it.

For me, being able to have a setup that is considered "portable" by the NEC definition saves me some potential regulatory hassle. That's why I went through the extra cost of buying an inlet and plug. That plus I like to unplug the generator from the house (ground and all) and plug it into a cheap electrical panel I use for my poor man's load bank. I ran a ground rod only for the use of this panel and bonded the neutral in the panel of course so no change is needed inside the generator. From there I have two 2 pole 30A receptacles for some garage heaters (11kw total) and a pair of single pole receptacles for some fans. Looking back, I got a pic of my clamp meter showing 67 or 68 amps with this setup. [Edit: I don't know how this was possible, in retrospect]

 

[69birdman]

Good point on the NEC, USAmilret you may want to check on that in your area. I kept mine mobile as well.

 

[gatorbob]

Fortunately my problem wasn't a building code / permitting problem but rather the utility company has rules about when they have to do their own approval for a customer to hook up a generator. I have no idea what kind of enforcement authority they may or may not have. But, their rules say if it's less than 15kW and "portable", they don't care to see a permit. They don't define "portable" but the NEC does and I figure that's a good organization to define things if I ever had any issues.

I think they want to have a list on file of people with standby generators with a proper transfer switch who clearly are not backfeeding incorrectly. I've seen lineman drive around after a hurricane a ask people to shut off generators while they work on part of the system. Their job is harder than mine and I have no problem pulling a plug so they can feel reassured things are safe.

 

[gatorbob]

. Duplicate

 

[tobyS]

For the guy that wants remote, we just bought 1500' of AL quad underground (2/0- 2/0- 2/0- 1) at 1.40/foot shipped....a super great deal.