Sign disconnect question

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Stuartm77

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Took over an abandon project that has large LED sign that draws 108 amps total.

previous owner/electrician/installer or whoever pulled 8 20 amp circuits out to sign and they are wired to the 8 circuits needed that are dropped down from sign..
Sign is currently working but my work inside will be inspected and inspector will likely look at sign as well.

Sign is for 1 establishment and all 8 circuits are needed to operate the sign.

Looking for suggestions on disconnect means to meet code.

I know It needs a disconnect and a separate sub panel would be great but trying to utilize what is already installed if possible.
Thanks in advance
 
The only thing I can think of is running the 8 feeds through contactors and have a switch (disconnect) to dump the contactor coil but I doubt that is legal
 
I think 600.6 is saying you need one disconnecting means that simultaneously opens all ungrounded conductors to the sign.

Can you come up with an 8 pole switch to use for this?
 
Eddie702 said:
The only thing I can think of is running the 8 feeds through contactors and have a switch (disconnect) to dump the contactor coil but I doubt that is legal
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that essentially makes the control switch the disconnecting means, which is an acceptable control means but not an acceptable disconnecting means.
 
I don't think that the code says "one and only one" disconnect-

(from 600.6)
Each sign and outline lighting system, feeder conductor(s), or branch circuit(s) supplying a sign, outline lighting system, or skeleton tubing shall be controlled by an externally operable switch or circuit breaker.
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It does not say that a sign must be supplied by only a single branch circuit or feeder (pretty much says that multiple branch circuits are allowed), it also doesn't say that all circuits must be opened simultaneously (only all parts of a MWBC).

Seems to me that a row of 8 switches would fit the requirement.

To lessen the "handle count" you could put in a small panel with 4 2-pole breakers.
 
zbang said:
To lessen the "handle count" you could put in a small panel with 4 2-pole breakers.
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But then you'd need a single, larger feeder, or breakers with individual line terminals.

It might be easier to use two 4p contactors 'controlled by an externally operable switch'.
 
zbang said:
I don't think that the code says "one and only one" disconnect-

(from 600.6)


It does not say that a sign must be supplied by only a single branch circuit or feeder (pretty much says that multiple branch circuits are allowed), it also doesn't say that all circuits must be opened simultaneously (only all parts of a MWBC).

Seems to me that a row of 8 switches would fit the requirement.

To lessen the "handle count" you could put in a small panel with 4 2-pole breakers.
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IDK, some potential controversy in there. Title is in plural form, "by an externally operable switch" is in singular form, then has "that opens all ungrounded conductors" within the same sentence. The multiwire circuit thing is mentioned in a separate sentence and references 210.4(B), which I did not double check what that says but should be something that would apply even if not mentioned here, so is mostly a reminder there is a rule elsewhere for multiwire circuits.

I don't know if they intend to allow multiple disconnecting means or not.

If the sign is a separate structure you also have art 225 limitations of a single branch circuit or feeder (and a multiwire circuit is still considered one circuit).
 
Apply Charlie's Rule and read the bold text in my post again-
nothing says only one supply to the sign (so multiple are allowed by this article),
nothing says that there must be only one disconnect (there's an explicit plural),
nothing says that all supply conductors must be opened at once (only those in a/each MWBC).

There is still the 225 consideration, but that's separate from the 600.6 question, however 600.6 implicitly recognizes that a single sign may have multiple branch circuits supplying it ("or branch circuit(s)"). There are a fair number of plural "branch circuit(s)" in 600.

The issue might be from 600.6(A)(1) "The disconnect shall open all ungrounded conductors where it enters the enclosure of the sign or pole." OTOH, throw in exception 2- add an internal panelboard and the disconnect requirement seems to go away.
 
I like the contactor idea. Install a single pole switch externally that controls the coil of (2) 4 pole contactors. A sign this big will surely have room for a 10" x 10" x 4" "J" box inside the sign. Just use one of the circuits for your control circuit as your contactor/coil has very little load.
 
Rick 0920 said:
I like the contactor idea. Install a single pole switch externally that controls the coil of (2) 4 pole contactors. A sign this big will surely have room for a 10" x 10" x 4" "J" box inside the sign. Just use one of the circuits for your control circuit as your contactor/coil has very little load.
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an electromagnetic contactor is not a suitable disconnecting means for any other application, why should it be acceptable here.
 
xformer said:
wouldn't a snap switch to control the relay be adequate?
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All that disconnects is the coil in the control circuit, the branch circuits are still energized and should anything happen that could bridge that control switch or mechanically close the contactor you can have unexpected closing of those branch circuits.

If you installed this contactor within the sign - it would still need disconnecting means ahead of contactor for all ungrounded conductors as well as for the control voltage if not derived from any the power conductors.
 
kwired said:
All that disconnects is the coil in the control circuit, the branch circuits are still energized and should anything happen that could bridge that control switch or mechanically close the contactor you can have unexpected closing of those branch circuits.

If you installed this contactor within the sign - it would still need disconnecting means ahead of contactor for all ungrounded conductors as well as for the control voltage if not derived from any the power conductors.
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Can you provide a code reference where it states this please?
 
Time to build one. They make this in a eight pole 40 amp.
 

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zbang said:
Acording to the OP, there are eight individual branch circuits out there, no feeder.
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If it is a sign attached to another structure that might be acceptable, if the sign is a separate structure I think it still requires a single feeder or branch circuit to comply with 225.30. I don't think there is anything in art 600 that would override 225.30 for separate structures.
 
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