100A shop feed - correct wire to use

[UpstateNY]

I have an existing shop with a 100 amp panel. The 4 wire cable has been run underground from the shop sub-panel to my house basement and terminated in a suitable plastic box. I have no questions or concerns regarding this cable.

Within the basement, I must run a 60' cable to the existing 200 Amp panel and connect the cable to a 100 amp breaker within the panel.

What is the name/type of indoor-rated cable I must run. I assume it, too, must be a 4 wire cable to support the 2 hot, 1 neutral and 1 ground wires.

Thanks.

 

[Crazyjake8493]

SER cable is what you need indoors. Sized the same as your underground wire, which would be 1-1-1-3 if using aluminum for a full 100 amp feed.

 

[UpstateNY]

Jake,

Yes, aluminum was used in the underground wire and I'll use the same for the basement cable.

Thanks so much.

 

[ard]

SER cable is what you need indoors. Sized the same as your underground wire, which would be 1-1-1-3 if using aluminum for a full 100 amp feed.

Did he mention the cable run is 473 feet?

Point is we cannot accurately size cable without knowing the total distance and conductor sizing for 'the run he has no questions about'....

Prolly OK, but just saying

 

[UpstateNY]

Existing underground cable is 60'. I have no concern that the underground cable is sized correctly and is of the proper type.

 

[Marctrees]

Upstate -

You do understand that ard is talking about voltage drop, NOT ampacity.

Yes ?

And you are correct saying you need four conductors... AND make sure the sub panel neutral bar is NOT bonded to the can w the often supplied green machine screw.

Marc

 

[UpstateNY]

Marc,

Yes.

At 100 amps, there will be a 1.05 % voltage drop over the 120 ft total length (60 feet
existing direct burial, 60 ft new SER cable within the basement) with both "sections" utilizing #1/0 aluminum conductors.

Also, at this time I don't weld in my shop so at most I'll be running 10-30 amps continuous load, so I will be fine. But I'll still have plenty of capacity for a welder if needed in the future.

Thanks to all for your help and guidance.

 

[wyliesdiesels]

1/0 is oversized for 100a.

But since youre running 1/0, you need to proportionately increase the size of the EGC as well.

 

[UpstateNY]

Wylie,

Several online wire size tools indicate 1/0 is the right size ? If that is correct, then 1-1-1-3 SER cable is the way to go for the 60' of wire running inside the basement. Same size wires for the existing underground section.

 

[PCustoms]

Wylie,

Several online wire size tools indicate 1/0 is the right size ? If that is correct, then 1-1-1-3 SER cable is the way to go for the 60' of wire running inside the basement. Same size wires for the existing underground section.

1/0 is not 1, and is not the wire gauge in 1-1-1-3 SER. How about you just tell everyone what is underground?

 

[UpstateNY]

I'll find out the size of the underground wire and report back.

 

[wyliesdiesels]

Wylie,

Several online wire size tools indicate 1/0 is the right size ? If that is correct, then 1-1-1-3 SER cable is the way to go for the 60' of wire running inside the basement. Same size wires for the existing underground section.

post the links of these online wire size tools.

BTW i dont use tools to size wire.

I go straight to table 310.15(B)(16) which is the core of the NEC.