Egress/Emergency Lighting

[bcorbin]

I sure hope I don't open up any old wounds here.

I have a business occupancy, with a backup generator for life safety type loads.

At the points of exit discharge, I have an egress lighting fixture above each egress door. I have these fixtures on an emergency branch circuit. In the electrical room, I have split this circuit into two parallel paths; one path goes through a lighting control panel relay (clock control). The other half goes through a normally-closed relay, controlled by a normal power branch circuit.

In an emergency condition, the light will always come on, regardless of time, but I can imagine someone at the user level not programming the lighting control panel correctly. This might make the egress lighting malfunction under normal power conditions.

In other words...can a fixture function as emergency, egress, and still be controlled under normal power conditions, or does it have to be foolproof? Any life safety codes obviously broken?

Thanks.

 

[Mr. Bill]

How does the lighting relay panel know emergency lighting needs to come on?

Is the lighting relay panel UL 924 listed to function as an emergency lighting control system?

The emergency lighting should be tested as part of the final inspection process. Should learn if it's programmed right at that time.

 

[Mr. Bill]

The lighting relay panels I have seen listed as UL 924 usually had some fine print note saying that if this function is being used for emergency lighting then only emergency lighting can be used by that relay panel.

 

[steve66]

I sure hope I don't open up any old wounds here.

I have a business occupancy, with a backup generator for life safety type loads.

At the points of exit discharge, I have an egress lighting fixture above each egress door. I have these fixtures on an emergency branch circuit. In the electrical room, I have split this circuit into two parallel paths; one path goes through a lighting control panel relay (clock control). The other half goes through a normally-closed relay, controlled by a normal power branch circuit.

In an emergency condition, the light will always come on, regardless of time, but I can imagine someone at the user level not programming the lighting control panel correctly. This might make the egress lighting malfunction under normal power conditions.

In other words...can a fixture function as emergency, egress, and still be controlled under normal power conditions, or does it have to be foolproof? Any life safety codes obviously broken?

Thanks.

IMO, if the power goes out, the fixture should come on no matter what the time clock says.

Other than that, I think you are free to use a time clock to turn off the fixture after hours.

Steve

 

[bcorbin]

How does the lighting relay panel know emergency lighting needs to come on?

That's just it...the lighting control panel doesn't need to know. That's the reason for the parallel circuit through the NC relay. If normal power fails, the emergency path feeds the fixture, regardless of whether the control panel "thinks" the fixture should be on or off.

However, you do raise a good point about UL 924. I will see if the lighting control panels

 

[steve66]

That's just it...the lighting control panel doesn't need to know. That's the reason for the parallel circuit through the NC relay. If normal power fails, the emergency path feeds the fixture, regardless of whether the control panel "thinks" the fixture should be on or off.

However, you do raise a good point about UL 924. I will see if the lighting control panels

I'm not sure what UL 924 is offhand, but IMO, its your relay that needs to be listed for use on emergency lighting circuits.

Steve