emergency light

mpj111

Emergency light or exit light ( lights turned on in the event of power failure).
When we wire emergency lighings, does it need isolating switch. Can it be hard wired without wiring through a switch.

Speedy Petey

No switch is needed.

Who is "we" ??

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jbfan

We sometime wire them through a switch for testing reasons.

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Yes I am a Pirate, 200 years too late. "Jimmy Buffett"

J. V.

jb......Not a bad idea. It is sometimes very difficult to get to the test button if they are high up. You're just killing power to see if they come on, right?

hpp58

Emergency and exit lights should never be wired to switches.
This way they will not be turned off by mistake and left off.
Check your building codes. There are a few rules on them.

handyman78

Depending on the size of the area- Isn't it just as easy to wire them to an individual circuit breaker for testing purposes? In a building I rent when the fire inspector comes in I throw the breaker off, all the lights come on and he is happy.

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jbfan

Yep. One place I worked required them to be left off for an hour every 3 months to check batteries.
We use a key switch.

__________________
Yes I am a Pirate, 200 years too late. "Jimmy Buffett"

micromind

It's always a good idea to connect the emergency lights to the same circuit as the room lights, but ahead of the switch. That way if the breaker protecting the room lights trips, the emergency lights will come on. If they're on their own circuit, you'd need a total power failure to get them to come on.

I can't recommend putting them on a switch, in this age of energy conservation, someone will very likely turn the switch off, then not notice the emergency lights on, and pat themselves on the back for saving electricity, then wonder why the emergency lights failed during an actual power failure. The key switch is a pretty good idea though.

Laugh all you want, here's an actual situation; a few years ago I got a frantic call from one of the local casinos, the power was out, and the generator wasn't running. When I got there, the engine block was stone cold (it should have been toasty warm), and the voltmeter on the battery charger read about 5 volts (it should have been about 27 volts).

It seems as though, in their effort to save electricity, management ordered all non-essential circuit breakers to be turned off. Apparently, the generator block heater and battery charger were 'non-essential'.

I know that sounds incredibly stupid, but it happened, and if the emergency light circuitry is not made as idiot-proof as possible.......

Rob

frenchelectrican

Did those " Dolt " mangement ever bother test the generator at reguar shedule time ??

Most place I useally see they don't bother test it much or test the generator much shorter than it should be and I have few pretty instering event with this but I will save it for other time.


Now for the emeregcy light circuit normally I useally wired ahead of local switch but it depending on how big the building and type of useage it may change a bit.

Merci,Marc

micromind

I don't think I've ever seen a casino test a generator at all. "It wastes fuel", "it's hard on the generator", idiotic excuses like that.

Care to guess who gets blamed when the power goes off and the generator doesn't start???

Rob

Big Bob

You Nevada sparky's need to sell a quarterly test.

? for the casino... how much does it cost you an hour if the video poker and slots are down? 1/2 the number.. do the test ... you will make out like one armed bandits...

Nationwide, If more than five McDonald's french fry cookers are down for and hour ...the results are seen on the Dow Jones index.

micromind

About 5 or 6 years ago, one of the larger casinos around here had a 600 amp emergency power feeder burn up at about 5PM on a saturday. I don't remember what year it was, but it was the weekend before memorial day.

Two restaurants, about 1/3 of the slots, and the cash vault were dark. When I got there (about 6PM), it looked like the entire police department was there, plus a few cars from a neighboring city. Apparently, since the cash vault was dark, they thought they were under attack!

Me and one other guy got it back up at about 9AM the next morning. I heard (I heard, don't know for sure) that they figured the loss at $510,000. Just for one saturday night! Obviously, I got into the wrong business!! lol.

The cause; this was a 480 volt 3 phase 3 wire feeder that went in PVC from the main electrical room under the slab, then up 3 floors to a split-bus distribution panel. The top half was 480, the bottom half was 120/208 3 phase 4 wire, via a transformer. This was installed about 20 years before.

The wire we pulled out (6-500MCM + 1-3/0 ground) was ok, except for an area about 60' from the feed end. Here, the insulation was burnt off for about 5'. Obviously, very hot.

Once we got the new feeder installed, I began to investigate. With everything turned on, we had about 370 amps on a 600 amp circuit. Nothing wrong with that. Grounds were where they were supposed to be on both ends. Then I looked closely at the split-bus panel. Everything looked good except a 225 amp 120/208 3 phase 4 wire circuit that had the neutral landed on the top bus. This bus was, in reality, the 480 ground bus. The 120/208 neutral bus was on the bottom. That meant all the neutral current from this circuit (about 80 amps) went through the ground system, building steel, etc. in order to get to the bottom bus.

I don't know this to be absolutely true, but it fits. The 480 feeder was in PVC, but there was very likely a steel 90 degree elbow installed where it turns to go up to the 3rd floor. This is a common practice, big wire pulls much easier through steel 90's than PVC. Since there was current going down the ground wire (from the 225 amp 120/208 circuit), but not the same current in the hot wires, it caused inductive heating in the steel 90. Eventually, it got hot enough to melt the insulation on the wires.

Maintenance had installed this 250 amp circuit about 3 months before the big blow-up.

I try not to work in casinos anymore, stuff like this is all too common. It's amazing to me that more of them don't catch on fire. On a positive note, working in casinos has taught me just about how much abuse electrical equipment will stand before it blows up!

Rob

P.S. I don't mean to bad-mouth casinos, a lot of industrial buildings have the same problems.