Emergency lighting

[monkeyhanger]

I need to replace around 20 non maintained bulkheads (like for like). The wiring in the building is around 20 years old, and there are 5 lighting circuits, and then a dedicated circuit for emergency lighting. The building is split into multiple areas that have different uses, the issue I have with replacing the fittings like-for-like (non maintained) is if the local lighting in one area of the building fails then the emergency lighting won't activate in that area- unless there is a power cut to the complete building (or phase that the emergency lighting circuit is fed from).

They don't want the original non maintained fittings replaced with maintained (electricity bill, cost of replacing tubes.. etc etc).

What do I need or what could I do (with relays?) at the consumer unit to cause the supply to the em lighting circuit to fail if any other lighting circuit fails? Would this comply or would it not be ideal, the building will be closed for another few months so perhaps it's best to suggest rewiring the emergency lighting from local circuits.

A 30mA RCD is used as a main switch for the full lot (1x three phase board). I'm not too happy about leaving that as it is either, and I'm having trouble getting MCBs for it (Terasaki, a brand I've never heard of)!

I'd appreciate anyones educated opinions

 

[pete555]

L.E.D Maintained only 4 watts cost to run pennies per year

 

[monkeyhanger]

At around £30 per LED fitting it would be about £360 more for the fittings than the like for like replacements, and probably not far off £100 a year in electric. Is there any suitable arrangement I can concoct at the DB to cut power to the emergency lighting circuit should any other lighting circuit fail.

- I'm just exploring all avenues and appreciate your input

 

[HandySparks]

Five normally open single or (or double) pole relays, one per lighting circuit. Each coil fed from one lighting circuit. Run the emergency lighting circuit through each of the relay contacts in series. Any one relay dropping out will turn the emergency lighting circuit off.

I'm not saying this will comply, just that it will work.

 

[Richard Burns]

Emergency lighting should be fed from the local lighting circuit in the area so what are the possibilities of refeeding sections of the circuit.
If the lights are only needed for a major emergency and if the loss of lighting in a non emergency is not dangerous then someone may have done a risk assessment that says they only need the system in place, sounds unlikely but could be possible.

 

[tazz]

At around £30 per LED fitting it would be about £360 more for the fittings than the like for like replacements, and probably not far off £100 a year in electric. Is there any suitable arrangement I can concoct at the DB to cut power to the emergency lighting circuit should any other lighting circuit fail.

- I'm just exploring all avenues and appreciate your input

Most bulkhead led emergency lights are nowthe same price or cheaper...£16 + vat
Using contactors, in a fail safe mode off local lighting circuits, would comply with BS 5266, as they would lite up areas which have failed.