I need technical specs to prove that I am allowed to have tandem breakers in a QO6-12L100S Series G3 Square D service panel. Also need specs for the maximum number of circuits I can put in this panel.

I asked about this panel before here:

https://www.askmehelpdesk.com/electr...wed-51950.html

TK said that the panel can support tandems and I have no doubt he is correct. However, the electrical inspector came out and he wants me to provide the technical specs to prove that tandem breakers are allowed. The inspector also wants proof that this service panel can support 6 circuits plus a 100-amp main.

If someone could point me to where I can find the technical specs I would appreciate it.

I've got the electrician installing retaining kits for the main breakers. Thanks, TK, for bringing that up.

My electrician mentioned that a grounding bar was needed for this service panel. Is this true? Upstream of the service panels will be a Cutler Hammer 6 Gang Meter Pack.

Here are the specs found at www. Squared.com:

Square D Online Catalog : Product Detail : QO612L100S

Yes an equipment ground bar is now needed for each panel, if I remember correctly, all the main disconnects will be located in the meter pack, so these panels must have the neutrals insulated from the equipment grounds.

I came back to add this after re-reading your post, why a 100 amp main in this panel? The main breakers are out in the meter pack?

Is there a way to have one main disconnect in the meter pack that covers the entire building - instead of having 6 breakers in the meter pack?

Then each service panel could have it's own main. The reason I ask is because it will cost an additional $720 to get a 200 amp breaker and 5 100-amp breakers for the meter pack and all the main breakers in the service panel are already there.

If this is not an option, I'll have the electrician remove the mains in the service panels and install breakers in the meter pack.

Sure you can have one main before all the meters and have a breaker in each panel, ONLY if the lines from each meter to each panel does not run to long inside usually no more than 10 feet of cable is allowed.

Is there a main disconnect in the meter pack? Or is a separate box installed before the meter pack? I am envisioning a setup like the one pictured.

I got this picture out of Illustrated NEC 2005, and in the caution box next to the picture it states, "On long runs it may be necessary to increase the feeder conductors' size to compensate for voltage drop 215.2(A)(3). I couldn't find anything stating the feeder conductor could only be 10' long. I'm estimating the run on this building will be somewhere between 15'-30' from meter pack to service panel.

Do you have the code that says the run can only be 10' from the meter pack to the service panel? And is there any exception to it I can take advantage of without relocating the service panels?

Thanks for all the help, very informative as always.

Forgot the picture.

There is no written 10 foot rule, NEC wants the main disconnect for each unit immediately as the feeder enters the building. You better check with local code and utility before you run unprotected feeders 15-30 feet.

Voltage drop is not an issue here.

Quote:

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Originally Posted by Ohio_Remodeler

I need technical specs to prove that I am allowed to have tandem breakers in a QO6-12L100S Series G3 Square D service panel. Also need specs for the maximum number of circuits I can put in this panel.

I asked about this panel before here:

https://www.askmehelpdesk.com/electr...wed-51950.html

TK said that the panel can support tandems and I have no doubt he is correct. However, the electrical inspector came out and he wants me to provide the technical specs to prove that tandem breakers are allowed. The inspector also wants proof that this service panel can support 6 circuits plus a 100-amp main.

If someone could point me to where I can find the technical specs I would appreciate it.

I've got the electrician installing retaining kits for the main breakers. Thanks, TK, for bringing that up.

My electrician mentioned that a grounding bar was needed for this service panel. Is this true? Upstream of the service panels will be a Cutler Hammer 6 Gang Meter Pack.

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A 6 Meter Pak still requires a 4 wire cabling to each "sub", that is why you need an EGC. (equipment ground conductor terminal bar bonded to the each enclosure.)

Quote:

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Originally Posted by Ohio_Remodeler

Forgot the picture.

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Also note that a master disconnect is only needed if the AHJ requires it. Six handles (tennant disconnects) are allowed on one structure as NEC compliant.[230.2]
Also note, the meter center needs one ground electrode conductor to at least two earthing ground electrodes.
The sub panels only require bonding to each respective unit separate water pipes if existing.
Nm

Quote:

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Originally Posted by Ohio_Remodeler

I need technical specs to prove that I am allowed to have tandem breakers in a QO6-12L100S Series G3 Square D service panel. Also need specs for the maximum number of circuits I can put in this panel.

However, the electrical inspector came out and he wants me to provide the technical specs to prove that tandem breakers are allowed. The inspector also wants proof that this service panel can support 6 circuits plus a 100-amp main.


My electrician mentioned that a grounding bar was needed for this service panel. Is this true? Upstream of the service panels will be a Cutler Hammer 6 Gang Meter Pack.

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Each subpanel (with ground bar) can be an MLO if the Panel and breaker temp ratings qualifies for use of 'Twin or Tandem' breakers. Note the 6 Pak meter center tenant 100's qualify MLO sub-panels. Google Square D.com nm