Central Emergency Lighting System for Large Manufacturing Facility


Senior Member
Madison, WI, USA
Hello all, I run facilities electrical for a large die casting manufacturer. I recently found myself in the middle of a power outage and noticed that the antiquated emergency lighting system was woefully inadequate. Now I'm looking at designing an entirely new emergency lighting system. One major problem with the existing system is that over the years (the factory is over 100 years old!), maintenance schmucks just tied in standalone EM fixtures into any old 120 volt (and some 277) circuit they could get their greasy hands on. Now periodic testing is a nightmare involving ladders and sometimes a scissor lift!

My goal is to design a central emergency lighting system, which I know is going to be expensive as a #@($#$*(! But I have been tasked with finding a sweet-spot combination of convenience (from a maintenance and testing perspective), energy efficiency, effectiveness (adequate emergency lighting to facilitate an orderly shutdown of dangerous die cast machines and melt furnaces), and, of course, cost.

I've gotten some quotes for a central inverter system which costs upwards from $60,000 to supply the power I figured we'd need. I planned to install all new LED high bay fixtures to serve the emergency load to help reduce the kVA required, but it's still a lot to get the light I feel we need.

My question is, first, does anyone have experience designing emergency systems? I could really use a lot of help here. The information I've found online is limited and lighting companies just want to sell me stuff.

Right now I'm looking at installing a DC lighting system for the emergency lights, completely separate from the existing high bays. Does anyone know the requirements for battery banks and transfer equipment that must be used? Do they require a specific listing? Or can a battery bank be assembled from individual UL 920 batteries and stored in a proper battery room?

To my mind, it is insanely stupid (and wasteful) to rectify AC power to DC to be stored in batteries, then changed back into AC via an inverter (where losses occur), then rectified back to DC again by the terribly inefficient LED drivers. Does anyone else share my viewpoint on this? I found a company who can supply the DC highbay fixtures, but the battery banks and transfer equipment have me stumped. I know Dual-Lite used to make DC emergency systems back in the day (I mean waaay back!)

Thanks in advance for any guidance you can offer.

Buck Parrish

Senior Member
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Every thing is going to require ROUTINE maintenance. . I like your idea about running new circuits. But I would consider a generator... JMO
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Senior Member
How big is the space? How much emergency kVA do you need? I would just provide standalone emergency 4500watts,277V, built-in battery inverter for each emergency circuit. Energize every other fixture from different circuit. I think small inverter have bigger competition and prices are lower.

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