700-15 Separate ATS for Emerg Lighting Circuits

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fredcallison

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NEC 700-15 "Loads on Emergency Branch Circuits" basically requires separate branch circuits for emergency lighting. Article 100 defines "branch circuit" as: "The circuit conductors between the final overcurrent device protecting the circuit and the outlet(s)." In my opinion this would allow a single ATS to feed a single panelboard with circuit 1 feeding lights and circuit 2 feeding a security panel.

We have been told we need a dedicated ATS for emergency egress lighting with a dedicated panel and another ATS with separate panel for the owner security control panel. Does anyone know where the requirement for a dedicated ATS is located?
 
Re: 700-15 Separate ATS for Emerg Lighting Circuits

Originally posted by fredcallison: NEC 700-15 "Loads on Emergency Branch Circuits" basically requires separate branch circuits for emergency lighting... Does anyone know where the requirement for a dedicated ATS is located?
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We don?t need to focus the discussion on the ATS. 700.15 says that you can?t power anything other than emergency lights from the ?emergency lighting circuits.? The feeder from the ATS to the panel is part of those circuits, as is the panel itself. To power the owner?s security loads from the emergency lighting panel is a violation of 700.15.

There is also 700.9(B). All of the wires and components from the (let us say) emergency diesel generator to the light bulbs must be independent of ?all other wiring and equipment,? with four exceptions. Connecting security loads to an emergency lighting panel is not one of the exceptions. I think that what you ?have been told? is correct.
 
Re: 700-15 Separate ATS for Emerg Lighting Circuits

If the concern is lighting only, then a possible out for you, is using flour. fixture mounted emergency ballasts. Then a possible interpretation is that the emergency circuit begins at the ballast, which is mounted in the fixture. You will have to bring an unswitched circuit to the fixture. The wiring within the fixture is then the emergency stuff, since the battery power originates at the ballast.
 
Re: 700-15 Separate ATS for Emerg Lighting Circuits

Charlie,

700.14 is titled "Loads on Emergency BRANCH CIRCUITS." Branch circuitry would not extend upstream from the final circuit breaker. Are the "Emergency Lighting Circuits" referred to in 700.15 limited to branch circuits by the title?


Fred
 
Re: 700-15 Separate ATS for Emerg Lighting Circuits

It might boil down to the AHJ's interpretation. I've given you my read on the paragraph. What do you think about the other citation - 700.9(B)?
 
Re: 700-15 Separate ATS for Emerg Lighting Circuits

Charlie,

700.9(B) allows wiring from the same source in the same raceway. Branch circuits 1 and 3 from the same panelboard would be considered from the same source.
 
Re: 700-15 Separate ATS for Emerg Lighting Circuits

It allows two emergency circuits from the same source to be in the same raceway. It does not allow one emergency load and one non-emergency load to be in the same raceway. Nor does it allow them to share a panelboard. Security systems are not emergency circuits. The whole point is to reduce the risk that a failure of the non-emergency load might cause a failure of the emergency load.
 
Re: 700-15 Separate ATS for Emerg Lighting Circuits

fredcallison

It is not just the transfer switch you will need to have two breakers on the genset also.

The breaker on the genset if it is feeding article 700 loads can not feed non article 700 loads.

Please note the part I made bold.

2002 NEC

II. Circuit Wiring
700.9 Wiring, Emergency System.

(B) Wiring. Wiring of two or more emergency circuits supplied from the same source shall be permitted in the same raceway, cable, box, or cabinet. Wiring from an emergency source or emergency source distribution overcurrent protection to emergency loads shall be kept entirely independent of all other wiring and equipment, unless otherwise permitted in (1) through (4):

(1) Wiring from the normal power source located in transfer equipment enclosures

(2) Wiring supplied from two sources in exit or emergency luminaires (lighting fixtures)

(3) Wiring from two sources in a common junction box, attached to exit or emergency luminaires (lighting fixtures)

(4) Wiring within a common junction box attached to unit equipment, containing only the branch circuit supplying the unit equipment and the emergency circuit supplied by the unit equipment
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This is strictly enforced in this area, we have installed Gensets with one, two and three breakers and transfer switches.

In the case of more than two breakers it is a design choice.

You said you are trying to power a security panel, most times you could provide enough battery power to run this for a week for less money than the transfer switch.
 
Re: 700-15 Separate ATS for Emerg Lighting Circuits

Fred
Does your system fall under the scope of 700.1?
 
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