adding circuits to my 200 amp service

[ssscamaro]

Hi,
I am in process of adding a 100 amp sub panel to my attached garage. I have the wires pulled to my 100 amp lug panel from my 200 amp service panel but not connected at the 200amp service. I am clear on connections at the 100 amp sub for the most part.
I was going to get electrician to connect my pulled wires to panels but as i progressed and read more and more decided to tackle cautiosly myself. I still may get my electricain to come over before using to look at but want to do majority myself and get good understanding of what needs to be done if i have someone else complete
1)First question is the "bonding screw" in my 100 amp sub/lug panel. i assume that is needed as my 200 amp main panel has neutral/ground attached together(bonded?).
2)In my 200 amp main (siemens) there are still 8 breaker spaces but all but 4 neutrals are filled. Is there a "add on" neatral bar i can purchase?It looks like panel has provisons for this or do i need one longer strip? How does this connect? What is its real name? Reason i need more is i have 1 circuit for garage (2/2/2/4) 100 amp, and 3 circuits for lights and outlets in basement i ran 2 years ago and never hooked up to panel. Was waiting to get electrician for that too. so i need 4 neutrals and 4 grounds on the strip
3)regarding neutral connection, existing has neutrals and grounds to same strip. The neutral and ground each occupy a space. I would guess thats the right way, but can they be doubled up? Neutral and ground in same space?
4)also for the #2 neutral for the 100 amp sub, is there some kind of adapter to go from the small size terminals to the #2 size? There is a existing 100 amp sub for generator switching panel that has something similar.It looks like it takes 2 small spaces on terminal strip and adapts to one for the larger wire size. Whats that called?
5) whats the "paste" called that should be used on the aluminum 2/2/2/4 connections? I see the original electricain used this on the incoming service. Does it get used on all connections involving the aluminum wire?
Thanks!
Ryan

 

[mrb]

to answer a couple of your questions:

in the sub panel, you need seperate neutral and ground bus bars. DO NOT install the bonding screw. The only place neutral and ground can be tied together is at the service. Use the neutral as neutral, and install a ground bar if the can didnt already come with one in it.


You cannot put more than one neutral under a screw. You can however put more than one ground under a screw as long as the bus bar is listed for it. If you are out of room for neutrals in your main, install an additional ground bar in the can and move some grounds over to that to free up some holes in your neutral bar.

 

[walrus]

The paste is called Noalox. I'd reccomend an electrician.

Neutrals and grounds should not be on the same buss in the sub. The neutral should not be bonded in the sub but the grounds should.

Some panels are rated for 2 wires under a lug, it depends on the panel, should be on the panel instructions on the cover?, Maybe you can look it up online?

 

[ssscamaro]

just read about the neutral /ground in the sub. in another post. as stated here that is how im set up seperate ground bar in the sub. I now understand that the second bonding in the sub would create paralel paths which is not desired, so no bonding screw in sub.
Also read that the grounds can be doubled up in the main service but not the neutrals.
Can the neutral terminal strip be added onto with some type of connector or jumper?

Ryan

ok just reread your post on moving grounds to seprate ground bar in main. That would just be ground bar screwed to panel ?

 

[mrb]

ok just reread your post on moving grounds to seprate ground bar in main. That would just be ground bar screwed to panel ?

yeah, look in your main, you should have a few places with a pair of formed holes a couple inches apart to install an additional ground bar. I know my SQD panels have like 4 places for a ground bar.

some mfgrs have neutral bus kits, but theyre big. easier and cheaper to just add a grround bar and move your neutrals to it and free up holes in the neutral bar.

 

[mrb]

I just reread this. Do you have 2/2/2/4 aluminum for the subpanel? If so, thats only good for 75amps or something. Check the NEC for the proper size for 100amps.

 

[Charles (in GA)]

I just reread this. Do you have 2/2/2/4 aluminum for the subpanel? If so, thats only good for 75amps or something. Check the NEC for the proper size for 100amps.

From a post I made in another thread recently where we were discussing 2-2-4 and 2-2-2-4 aluminum direct burial wire.

NEC 310.16 does indeed specify that it (2-2-2-4) is for direct burial or conduit, and #2 AL, 90°C, USE-2 (which is what 2-2-2-4 twisted AL intended for direct burial is rated as) is good for 100 amps at 90C and 90 amps at 75C.


You really cannot make full use of the 90°C rating as there are few 90°C rated connections (breakers and other devices) and you are required to use the lowest common denominator, temperature wise, when determining circuit protection amp ratings. The 90°C wire ratings do however shine when you need to derate wire due to high ambient operating temps, or number of conductors in a conduit.

End result is that 2-2-2-4 and 2-2-4 AL cable is generally only good for 90 amps, depending on the cable type.

Charles

 

[LoneGunman]

"You really cannot make full use of the 90°C rating as there are few 90°C rated connections (breakers and other devices)"

Yup, and it has bitten quit a few of the book knowledge only crowd in the ****. They see the 90 degree table and think they are good to go, until the inspector asks to see the documentation that states the breakers and lugs are also rated for 90 degrees.

 

[Aceman]

1)First question is the "bonding screw" in my 100 amp sub/lug panel. i assume that is needed as my 200 amp main panel has neutral/ground attached together(bonded?).

Do not use the bonding screw. Neutrals must float.

2)In my 200 amp main (siemens) there are still 8 breaker spaces but all but 4 neutrals are filled. Is there a "add on" neatral bar i can purchase?It looks like panel has provisons for this or do i need one longer strip? How does this connect? What is its real name? Reason i need more is i have 1 circuit for garage (2/2/2/4) 100 amp, and 3 circuits for lights and outlets in basement i ran 2 years ago and never hooked up to panel. Was waiting to get electrician for that too. so i need 4 neutrals and 4 grounds on the strip

You're looking for a grd bar. They come in various lengths. 5 space, 10 space, etc. Spaces being holes. They come with machine screws in the package, you simply need to drill/tap two 8-32 holes to mount it. Move as many of the ground wires to this bar until you have enough space for your neutrals on the factory neutral bar. All of the grd bars I've seen allow for 2 ground wires per hole also. Neutral wires each get their own hole.

3)regarding neutral connection, existing has neutrals and grounds to same strip. The neutral and ground each occupy a space. I would guess thats the right way, but can they be doubled up? Neutral and ground in same space?

See above.

4)also for the #2 neutral for the 100 amp sub, is there some kind of adapter to go from the small size terminals to the #2 size? There is a existing 100 amp sub for generator switching panel that has something similar.It looks like it takes 2 small spaces on terminal strip and adapts to one for the larger wire size. Whats that called?

Siemens calls it a collar strap, I believe the part # is either ECCS1 or CS1.

5) whats the "paste" called that should be used on the aluminum 2/2/2/4 connections? I see the original electricain used this on the incoming service. Does it get used on all connections involving the aluminum wire?

Noalox, De-ox, Penetrox are some common names. I personally use it when terminating aluminum wires.

FYI, if this attached garage is being fed with #2 al SER, under the 08 code, it is now limited to the 60 degree ampacity column-75 amps. Which means you can round up to an 80 amp breaker if your calculated load is less than 75 amps otherwise you round down to a 70amp breaker.

 

[Torque1st]

"You really cannot make full use of the 90°C rating as there are few 90°C rated connections (breakers and other devices)"

Yup, and it has bitten quit a few of the book knowledge only crowd in the ****. They see the 90 degree table and think they are good to go, until the inspector asks to see the documentation that states the breakers and lugs are also rated for 90 degrees.

Code reference please.