another wire question......

[geonc]

searched but came up empty..... been lurking a while and finally can post.

I am running 100' of Stephens 2-2-4 AL URD to my garage..this is direct burial wire and I do plan on burying the last 20'.....

Main panel is outside on opposite end of house and my plan is to run a
1 1/2" LB from panel ....90deg pipe to under crawl space then run across floor joists---securing with staples--- 60' then drop into 18" trench for the last 20' to 3" 90 deg PVC sleeve I put in before pouring slab then another piece of 1 1/2" Carlon to garage sub panel.

Is it nesc to pipe the entire run in the crawl space????
No UV will hit this wire obviously and it is common to see other wires--AC, cook top, water heater feeds run like this.....

thanks for your help!

 

[pattenp]

I've got bad news for you. If you are running this as a branch feeder from your main panel then you need to use 4 conductors, such as 2-2-2-4. Also URD is not rated to run inside a structure, it can only be used outside. To enter the structure you'd need to transition to a different cable such as SER. Also any cable that does not have an overall outer sheath needs to be in conduit when inside. Mobile Home Feeder can be run inside in conduit and also direct buried.

It helps to know if you are in the US.

Edit: Southwire Stephens URD or Triplex is just USE-2 rated and does not have fire resistant insulation is why it can't be installed inside of a structure. And the reason for four conductors is you need to have an equipment ground. Triplex is two phase conductors and a neutral.



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[geonc]

Thanks for reply!
Plan is ..from what I have read is to sink 2 ground rods 6' or so apart then run 6ga from garage panel to ground rods...not correct?

Guess I need to fill rest of info...I live in North Carolina.

confused on transition??? 6' of wire that runs above grade from slab sleeve will be in 1 1/2" Carlon pipe to 125 amp panel mounted inside garage with 100 amp breaker feeding from house main....neutral "NOT" bonded to panel in garage panel...

not sure what I am misunderstanding but appreciate your patience

 

[geonc]

ahhh...caught your edit after my reply..apologys.

OK..no worries..just buy more 1 1/2" Carlon...it is a straight run.

 

[pattenp]

The equipment ground wire from the main panel to the garage sub-panel is different from the electrode ground rod wire. You need the two ground rods at the garage connected to the sub-panel plus the equipment ground running from the main panel to the garage sub-panel. The feeder wire from the main panel can be SER from the panel all the way under the house and changed to a direct bury cable such as MHF to go to the garage. The SER doesn't need to be in conduit inside the house but MHF does. Using URD is a pain because you can't pull it to the inside of the building and have to splice on cable that is rated for inside use.

 

[pattenp]

ahhh...caught your edit after my reply..apologys.

OK..no worries..just buy more 1 1/2" Carlon...it is a straight run.

Just too make sure you understand. The URD is not to be used inside or under your house even if in conduit. It's not fire retardant rated.

 

[wyliesdiesels]

The #6 cu wire that u run to ground rods is called the GEC and that's mainly for lightning suppression. The 4th wire pattenp is talking about is the EGC(equipment grounding conductor) and is required for the clearing of possible faults on the feeder circuit.

The cable you have needs to stay outdoors because of it's rating. Sure, u could do whatever you want, but if it ever gets inspected or u try to sell the house, you could get called out on it and would have to change it! URD is primarily and typically used by POCOs to distribute power to a house main service panel from say an underground or pad mounted transformer. Also, #2 al is good upto 90a, so make sure you use a breaker rated no more than 90a.

 

[pattenp]

Thanks for reply!
Plan is ..from what I have read is to sink 2 ground rods 6' or so apart then run 6ga from garage panel to ground rods...not correct?

Guess I need to fill rest of info...I live in North Carolina.

confused on transition??? 6' of wire that runs above grade from slab sleeve will be in 1 1/2" Carlon pipe to 125 amp panel mounted inside garage with 100 amp breaker feeding from house main....neutral "NOT" bonded to panel in garage panel...

not sure what I am misunderstanding but appreciate your patience

wyliesdiesels already caught this, I was too engrossed in the URD. But, yes only max of 90A on the #2 al. If this was a main service feed then 100A is okay. Don't ask why, just one of those NEC things.

 

[geonc]

AHHHH...thought I got a deal on the wire...now I know why!
Damn.....

 

[pattenp]

AHHHH...thought I got a deal on the wire...now I know why!
Damn.....

If you got it from Lowes or HD you can take it back. Did someone suggest this wire to you? Electrical supply houses aren't very good about taking back cut wire.


Edit: Look for Mobile Home Feeder in 2-2-2-4. I know Lowes carries it. Make sure the rating on the cable is USE-2/RHH/RHW-2.


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[geonc]

If you got it from Lowes or HD you can take it back. Did someone suggest this wire to you? Electrical supply houses aren't very good about taking back cut wire.


Edit: Look for Mobile Home Feeder in 2-2-2-4. I know Lowes carries it. Make sure the rating on the cable is USE-2/RHH/RHW-2.*

Supply house sadly.....well $150 lesson there......yea counter guy suggested...prolly had it laying around and needed to unload it.....

thanks again for your help and patience

 

[pattenp]

Supply house sadly.....well $150 lesson there......yea counter guy suggested...prolly had it laying around and needed to unload it.....

thanks again for your help and patience

If you told him what you needed it for then he sold you the wrong wire. He should take it back. That wasn't your fault.

The last time I checked at Lowes and HD the 2-2-2-4 MHF was $1.47 a foot.

 

[ishiboo]

Also... NOT bonding the neutral to ground AND not having the fourth conductor eliminates completely the protection offered by the ground conductor... just so you know. It was legal to run 3-wire service before, but you would have had to bond the neutral and ground in the sub-panel.

Being individual wires and not a listed cable, can he not just add a single #2 wire to the bundle and use what he has?

 

[pattenp]

Also... NOT bonding the neutral to ground AND not having the fourth conductor eliminates completely the protection offered by the ground conductor... just so you know. It was legal to run 3-wire service before, but you would have had to bond the neutral and ground in the sub-panel.

Being individual wires and not a listed cable, can he not just add a single #2 wire to the bundle and use what he has?

That is an option. But it doesn't solve the problem of not being able to run the URD inside the house.


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