Small central UPS for converting circuit to emergency lighting

[Martin]

I am looking for a product to convert an existing lighting circuit in a communal stairwell to be emergency battery backed up. There are 6x 7W LED mains fittings, so say a max 50W load. I could just add emergency lighting fittings, but wiring and access is difficult.

It also needs to have a switched line input, so existing switches can still be used to turn lights on/off. All switch lines come back to central junction, before going to light fittings. I am struggling to find a suitable unit.

 

[snowhead]

So all you are trying to do it run the lights when the power goes off?

Fit a suitably sized UPS at the DB /CU to give the maximum time required.
From lighting MCB (plus N plus E) into UPS.
Connect outgoing of UPS to L, N, E of lighting circuit.
Existing switches remain.

Probably doesn't comply with E.M lights standards.

 

[westward10]

This is going to be essentially a central battery system. The cabling would need to have some kind of fire resistance and possible separation from other circuits. These lights are also switched meaning they may not function in the event of a power failure if switched off.

 

[snowhead]

Is this proposed E.M system a "Nice to have" or mandatory?

 

[StephenRowley]

Also what happens when a fire burn though the central battery back?

 

[davesparks]

The easiest thing would probably be to fit self contained maintained fittings with microwave sensors and convert the s/l to permanent live with key switch for testing.

Adding an invertor/central battery will require all cables to be fireproof, so it will probably need to be completely rewired.
[automerge]1575295412[/automerge]

Also what happens when a fire burn though the central battery back?

That's a bit of a daft question, the answer should be ridiculously obvious.

This is why there are rules about the type and location of central batteries for emergency lighting.

 

[Martin]

Thanks for the replies, but no product suggestions so far.

Cable is MI, so is fireproof.

Essentially what I'm looking for is a very small central battery system, but these all seem to be designed to power whole buildings.

I can't find anything between this below link (8W), and a large central battery system.

Innovative Emergency LED Lighting Kits

Compliant emergency lighting conversion kits and emergency lighting lamp kits for upgrading standard luminaries. Widens emergency lighting options on existing lights or designer lamps.

mountlighting.co.uk

I can't just use a standard UPS as it doesn't have a switched live input for functional switching of the lights. Also I'm sure wouldn't comply with EL standards anyway.

 

[westward10]

That is a whole lot of effort for a few lights. Do you have a copy of BS5266:1

 

[SparkyAndGeorge]

Is there a reason you cannot do what dave sparks has suggested previously?

 

[Martin]

Is there a reason you cannot do what dave sparks has suggested previously?

I may need to go this route, but finding suitable looking fittings isn't easy. The client would prefer to keep the existing fittings and doesn't want a bunch of EM bulkheads.

Also since the switches are wired separately from the light fittings, it seemed the easiest option to just add one battery box with inverter.