Wire Identification

[AustinScoobee]

Hi Everyone, We have a house which when built , had plans for future expansion. They left in the walls a wire from the panel (not connected!) to the outside when the addition would go.We wanted to know what this wire could be used for, or is it big enough to feed a subpanel for the planned expansion?

The wire is marked : essex 4-4-4 type se ?HHW

I know an electrician would be able to help but I hate to bother them with what should be a simple question, and most contractors round here would much rather trench a new feed or tear up our walls to get a feed....So.. How many amps could it feed ?.

Amny help very much appreciated G

[gfretwell]

4 gauge is generally good for 85a copper or 65a aluminum but if this is really only 3 wire you can't use it for a sub panel. If this is really 3 insulated 5 ga conductors with a concentric wound bare ground (usually called SER) then it is OK for a sub.

[AustinScoobee]

On second look with my glasses on! its : "essex 4-4-4 type se XHHW CDRS 600volt" Then this marking repeats. What if not a sub panel was this for? Cheers, G

[Doug Miller]

Type SE = Service Entrance

SE cable is used to connect the power company's lines to the meter base, and the meter base to the service entrance panel (main panel). Four conductors are not necessary at that point, because the fourth wire originates at the main panel, not at the utility transformer. A feed from the main panel to a subpanel needs four conductors.

That said... you might *have* four conductors -- three insulated conductors with a wire mesh sheath wrapped around them.

[RBM]

If it just listed the three numbers, it would indicate only three conductors, so it probably wasn't for a sub panel, at least a 120/240 volt sub panel. It could have been for an air-conditioning condenser unit or heat pump

[Steve Barker LT]

Some kind of BODACIOUS heat pump there with 100a service.

[RBM]

What 100 amps, it's only good for 65

[AustinScoobee]

Hi everyone, Sorry to resurect an old thread, but I had to relate this. We had an electrician out. He told us this wire was likely for a planned addition and this would be for a feeder to the addition's sub panel. Confused, I said to him "but we have only 3 conductors, and no ground?" To this he replied:

"It is common practice to ground the sub panel AT the subpanel, there is no need to run a ground from the main breaker box. This also saves copper."

So ... Is this indeed common practice/code?

G

[Bud--]

Not grounding to the originating panel is only permitted for a separate building (like a garage). And probably won't be allowed for separate buildings in the 2008 NEC.

-- bud--

[AustinScoobee]

Thanks very much bud.. So, would we be able to use a separate ground from main to subpanel and still use the wire? It just wouldnt be routed the same way, as the

4-4-4 is. Thanks g

Bud-- wrote:

[Steve Barker LT]

Running a separate ground is ok, BUT it must follow the same path as the cable.

[Doug Miller]

Close, but no cigar: Code requires all conductors to run in the same cable, conduit, or raceway. If the cable is already in a conduit, fishing another wire through the same conduit meets this provision of the Code. Simply running another conductor parallel to an existing cable does not.

[Steve Barker LT]

Hmmmm. That's contrary to what I was told locally by my electrician. He told me I could run a 4/3 NM and staple a bare #6 right next to it . (this is all inside of course) Of course if there was a 4/3 w/ground, that'd be great.

[Bud--]

Have your electrician look at NEC 300.3-B

(An inspector could allow it.)

-- bud--

[Steve Barker LT]

ok, thanks for the ref.

[gfretwell]

This inspector would point you to 300.3(B)(1) and 250.130(C) When retrofitting a ground to ungrounded systems there is latitude in several articles you can take advantage of. If you can deal with the possibility of physical damage most thinking inspectors would rather see a grounding connection than not having one, even if the method is less than perfect. Just deal with the physical protection.

In new work we want to see the conductors grouped in one wiring method.