Transfer switch installation

[bigmaca]

Hey guys,
ie
Need your help. I've started a new job installing residential 8kw Generac Generators. I've never done generator installations before last week. I live in Mass. My question is about the actual transfer switch. Specifically the neutrals only. Those guys that install transfer switches understand that the neutrals are labeled 1-12 on a 12 circuit panel. Can I remove the neutrals from the transfer switch and just tie in the main neutral from the transfer switch to the main neutral bar in the main panel? So I would eliminate the 12 neutrals from the transfer switch and tie the main neutral only. The only reason I am asking is because it would keep the main panel extremely clean. I do want to follow the code.

Thanks guys!

Mike

 

[GoldDigger]

Hey guys,
ie
Need your help. I've started a new job installing residential 8kw Generac Generators. I've never done generator installations before last week. I live in Mass. My question is about the actual transfer switch. Specifically the neutrals only. Those guys that install transfer switches understand that the neutrals are labeled 1-12 on a 12 circuit panel. Can I remove the neutrals from the transfer switch and just tie in the main neutral from the transfer switch to the main neutral bar in the main panel? So I would eliminate the 12 neutrals from the transfer switch and tie the main neutral only. The only reason I am asking is because it would keep the main panel extremely clean. I do want to follow the code.

Thanks guys!

Mike

It sounds from your description as if you are talking about the circuit-by-circuit manual transfer switch kit in which you pull wires from the breaker of each generator fed load from the main panel, run through the one of the circuit transfer switches and the run the TS output back into the main panel where it is connected to the load wire.

If you pull only one combined neutral instead of individual neutrals, you would have to use a suitably larger sized neutral and you would make it impossible to use either GFCI or AFCI breakers for those circuits in the main panel.
I cannot say for sure that it would not be allowed by the NEC, but I certainly would not do it!

Do the transfer panel switches also switch the neutrals or is there just a set of isolated terminals in the box to allow you to keep the neutrals and the hot wires running together the whole way?

The only such TS I have looked at had the option of connecting the generator neutral directly to the main panel and not running the individual load neutrals into the TS at all. But that was back in the days when the generator itself did not have a neutral to EGC bond built in.

 

[bigmaca]

One neutral is over sized. And the other 12 neutrals from the transfer switch panel to the main panel are 12 THHN. In the event of an arc fault or GFCI the guy that I worked with left a couple of the neutrals from the TS to the main panel intact. Although he pulled the other 10 neutrals to me it was more important to see if this even allowed. Because the next day I worked with another guys that kept all 12 neutrals and the oversized neutral. Again to me it's about learning what's the proper code as to my OCD with keeping a clean main panel with a bunch off neutrals tied together. I appreciate your help!!

 

[GoldDigger]

One neutral is over sized. And the other 12 neutrals from the transfer switch panel to the main panel are 12 THHN. In the event of an arc fault or GFCI the guy that I worked with left a couple of the neutrals from the TS to the main panel intact. Although he pulled the other 10 neutrals to me it was more important to see if this even allowed. Because the next day I worked with another guys that kept all 12 neutrals and the oversized neutral. Again to me it's about learning what's the proper code as to my OCD with keeping a clean main panel with a bunch off neutrals tied together. I appreciate your help!!

The most important single thing we need to know about your setup is whether the TS switches the neutral conductors or not.
If you can provide a link to the installation manual or else the exact model number of the TS panel we could give a lot better advice!

 

[texie]

One neutral is over sized. And the other 12 neutrals from the transfer switch panel to the main panel are 12 THHN. In the event of an arc fault or GFCI the guy that I worked with left a couple of the neutrals from the TS to the main panel intact. Although he pulled the other 10 neutrals to me it was more important to see if this even allowed. Because the next day I worked with another guys that kept all 12 neutrals and the oversized neutral. Again to me it's about learning what's the proper code as to my OCD with keeping a clean main panel with a bunch off neutrals tied together. I appreciate your help!!

You can't use a common neutral, even if oversized. See 200.4. There are a few exceptions but none that would apply here.

 

[GoldDigger]

You can't use a common neutral, even if oversized. See 200.4. There are a few exceptions but none that would apply here.

But for all we know, the circuit neutrals may not even have to come into the TS enclosure at all.
So in that sense, the OP could get what he wants without using a common neutral.

 

[Shanky]

The larger neutral is sized for the sub-feed breaker,(in the main panel) that is feeding the TS and it's included breakers. The provided neutrals (1-12) would connect and be paired to each 120v circuit neutral that is being moved to TS , basically TS is becoming a sub-panel, do to containing multiple breakers. Yes, the main panel can get hairy with wire nuts and tracing neutrals in 'jam packed' panels, along with dealing with shared neutral situations, takes some thought.

 

[GoldDigger]

So far the OP's post could either describe
1. a manual transfer switch in which only the circuit hot and neutral are brought in and the corresponding breakers in the main are no longer used. Or
2. A circuit by circuit manual trannsfer switch in which the breaker output and the load wire are brought to individual switches in the TS enclosure. When fed from POCO the protection is via the original breaker while when on the generator the circuit is protected by a mini breaker in the TS panel.

Which do we have here?

Tapatalk!

 

[Shanky]

I assumed he was referring to Generacs, Pre-pack EZ Switch, which depending on size of gen will include 8 to 16 breakers as a combo auto transfer switch/panel.

 

[goldstar]

The OP should really be posting this but this is the unit I believe he's talking about :

http://www.electricgeneratorsdirect.com/Generac-Guardian-6237-Standby-Generator/p10669.html

This is the spec sheet on the xfer switch.

http://www.electricgeneratorsdirect.com/manuals/rtg_inst_man.pdf

If this is, in fact, what is being used it's a sub-panel/xfer switch combo and the design is such that the neutrals have to originate in the same panel the branch circuits are fed from. The neutrals in this panel float and the neutrals in the main panel are bonded to the EGC.
Because there is no way of knowing if the selected circuits are MWBC's the panel has to conform to a generic design. if you look at 210.4

210.4 Multiwire Branch Circuits.
(A) General. Branch circuits recognized by this article shall
be permitted as multiwire circuits. A multiwire circuit shall be
permitted to be considered as multiple circuits. All conductors
of a multiwire branch circuit shall originate from the same
panelboard or similar distribution equipment.

So, from an electrical operation point of view your idea would work. However, I believe you would be in violation of this section. Just my opinion.

 

[ceb58]

The most important single thing we need to know about your setup is whether the TS switches the neutral conductors or not.
If you can provide a link to the installation manual or else the exact model number of the TS panel we could give a lot better advice!

This guy is talking about the 12-16 circuit ATS that come with the smaller generators. No switched neutral.
But IMHO it would be a violation not to carry all the neutrals.

300.3 Conductors.

(B) Conductors of the Same Circuit.
All conductors of
the same circuit and, where used, the grounded conductor
and all equipment grounding conductors and bonding conductors
shall be contained within the same raceway, auxiliary
gutter, cable tray, cablebus assembly, trench, cable, or
cord, unless otherwise permitted in accordance with
300.3(B)(1) through (B)(4).