Service panel wire pull to sub-panel

[lhc_cj7]

I want to put a 100 amp sub panel in the garage for a welder and compressor along with future options. I had plans of doing the job myself but decided to see what the cost would be for a licensed sparky. They wanted $1250 which consisted of all material, 75 feet of 4 copper wire thru the attic in conduit to the garage and hook up the sub along with installing the 2 outlets. Not sure if that’s market value?

After that I stopped by city hall to chat with the building inspector. Things I found out:
Conduit in the attic is a must
the NEC load calculation is not needed, all new homes in town are 200 amp service and adding the 100 panel is within there limits.
I can hook up everthing up myself
Permit cost is $105
He doesn't advise using aluminum but is within the city code.
2 copies of the sub panel location and outlets being installed
Wire, breakers must be rated for 75c.

So I wobbled back to doing it myself until pulling the service panel cover to find this.

There is no room left in that knock out for additional wires. So what do I do? Will four strands of 4 gage wire fit thru one of the remaining knock outs? Will code allow using 2 knock outs and then combining them into the conduit?

I have more questions about the small stuff involved with this job but will wait for now.

 

[Charles (in GA)]

Conduit in the attic is a must

Must be a local requirement.

He doesn't advise using aluminum but is within the city code.

Aluminum, properly done is quite safe and will last as long as copper.

Wire, breakers must be rated for 75c.

Not really an issue, virtually any new wire and breakers you buy will be 75°C or better anyhow.

So I wobbled back to doing it myself until pulling the service panel cover to find this.

There is no room left in that knock out for additional wires. So what do I do? Will four strands of 4 gage wire fit thru one of the remaining knock outs? Will code allow using 2 knock outs and then combining them into the conduit?

Code will not allow you to split the wires in a circuit between two knockouts.

Charles

 

[mrb]

all the wires have you go through the same hole, you cannot put 2 through one hole and 2 through another. There is good reason behind this.

#4 is only good for 90amps. You dont need 4 #4s, thats a waste of money. Use 3x #4 and a #8 for the ground.

You talk about running wires through holes into the panel, what exactly do you plan to do? If the inspector wants it in conduit in the attic, just run it in conduit all the way.

You can use a hole saw or punch to make the hole you need in the panel, then use a washer (not regular washer, they make ones for this purpose) on either side of the hole, and a bonding locknut on your conduit (or flex) fitting.

If you make a hole in the top of the panel, be VERY careful to not nick one of the wires going into the 200a breaker, since those have no overcurrent protection it will make a big boom and a big, costly mess if you hit one with your drill.

Your electricians price seems reasonable. You can do it yourself, but make sure you do it right. Your materials cost will probably run around $600 by the time youre done.

 

[porschedude996TT]

Move the other cables to the smaller knock-outs and use the large one for the new cable.

 

[nadogail]

If you elect to do this yourself be on notice: PULLING WIRE IS NOT A ONE MAN JOB. As a minimum you need 2, a puller and a feeder. Use lots of wire lube is one person will be doing all the pulling by hand.

 

[kvom]

PULLING WIRE IS NOT A ONE MAN JOB

x2 For my garage the wires had to pass only one LB and one 90 degree elbow, and it took two young, strong guys to get it done.

 

[lhc_cj7]

Move the other cables to the smaller knock-outs and use the large one for the new cable.

Hmmmmmmm!!!!!!!

 

[lhc_cj7]

all the wires have you go through the same hole, you cannot put 2 through one hole and 2 through another. There is good reason behind this.

Your electricians price seems reasonable. You can do it yourself, but make sure you do it right. Your materials cost will probably run around $600 by the time youre done.

Good sanity check, thanks

 

[lhc_cj7]

If you elect to do this yourself be on notice: PULLING WIRE IS NOT A ONE MAN JOB. As a minimum you need 2, a puller and a feeder. Use lots of wire lube is one person will be doing all the pulling by hand.

What about pulling the wires down into the service panel first. Then lay the remaining wire across the attic, then feed the wire thru the conduit one piece at a time? I can see this taking more time but I'm not in a hurry.

 

[nadogail]

Wires are pulled in all at the same time. As easy as it might be to pull the first of several conductors into a conduit, the next ones get exponetually harder.

You might start with the "A" end of your wiring bundle from a pull box at the center of a run, then pull the "B" end from the same box to the other end of the run.

Conduit runs should be planned for easy pulling. THe first step is to determine what conductors will be used in the circuit. After, you know what is going into the conduit, you pick the size of the conduit to use. For only a little more cost you can have a larger size tube that is easier to pull through. Bends in the conduit add to the effort required. The absolute max is four 90 degree bends or equivalent (two 45's are equal t0 a 90) between wire feeding points.

This method will require a pull box in the center of the run, and lots of wire pulling lube. Wire pulling lube is a wax like product with a waterlike solvent.

A common mistake by the "DYI" crowd is taping the conductors together along the length of the pull. I avoid this so that I can adjust the indvidual conductors as they are pulled.

The ends of the conductors are knit, taped, or woven together and attached to the puller. I use a "fish tape". Sometimes rope is used. If you are going to pull into an energized panel (not recommended) a non conducting pull tape has obvious advantages.

 

[Torque1st]

For that price let the sparky do it but check on that ground wire size.

 

[walrus]

What about pulling the wires down into the service panel first. Then lay the remaining wire across the attic, then feed the wire thru the conduit one piece at a time? I can see this taking more time but I'm not in a hurry.

NEC wants the wires pulled into a completed conduit system but what you suggest is done all the time

 

[carguykeith]

One thing I found helpfull was buying an aditional 3ft extra conductor length than needed and cutting the conductors down so that they were stagered (starts with just 1 wire and works up to all 4). The advantage here is that at each turn you are only initiating a bend in 1 wire at a time.

Oh yeah and no joke on the hard work, I had a 15' pull with one 90 and it was a sweat fest by myself. Two people would be REQUIRED for any long pull like that...

 

[nadogail]

Congradulations on getting the wire pulled in.

Gail Brownlow
Anchorage High School, 1958

 

[lhc_cj7]

Based on the help here, some of my questions to others and I'm just south of 50, I have come to the conclusion.....I'm not doing this.

I'm going to hire an electrician. Several more came over yesterday so I'll wait for there quotes.

I'll keep you posted. Thanks for the help.

 

[RoadBeater]

I agree with laying out the wire and slip the conduit over it then glue it together. The big wire is not easily pulled thru. I did this on 150' run to my barn, then set it all in the trench.

 

[700jfm]

That's how I did it twice. One time in the attic, pulled that out and put it in the ground.

 

[RoyB]

as the other guy said, number 8 is adequate for 100 amps for the ground. our code here lets you use 100 amps in a 1" conduit if its a subfeed like you are doing. 1200 bucks to add a subfeed in conduit through the attic is not a bad price imo. we charge 1200 for a panel upgrade and its about the same amount of work. I would avoid using alum wires because you will have to use larger wires than copper, thus needing larger pipe and its not as easy to pull because it has a different coating on it.

i would let the sparky do it for that price though. panel, wire, and breakers will cost 300-400 bucks by themselves easy.