Maintained Emergency Lighting

[mte29]

Hi, can someone clarify how to wire maintained emergency lights please. Setup is a bar which needs 12 maintained emergency lights which also includes two permanently illuminated exit signs.

Thanks

 

[ColJack]

maintained IS permanently on..
non-maintained is they ony come on in the event of a mains failure.

you just wire a live, neutral and earth to them, unless they are switchable, in which case you also want a switched live..

the live to them should go through a keyswitch so that they can be tested.. regularly

 

[Spark123]

Depends on what make and model - maintained usually means they need have a switch live, a permanent live, neutral and earth.
It is possible to do away with the switch live and just link the perm live to the switch live so it is illuminated permenantly.
Some of the exit boxes I have seen recently need to be wired slightly different - they are sold configured as permanently on and to make them switch you remove a link and replace it with a switch. Only issue there is you need one switch per unit and can't (unless you're feeling inventive with relays) have a common switch live.
Don't forget the lights should have a test switch which kills the supply (live and switch live) to them.

 

[ericmark]

Same as any normal ceiling rose.
Line non switched
Line switched
Neutral
If required Earth
The two permanently illuminated exit signs will have link between Line non switched and Line switched and be supplied from line non switched.

Do ensure both switched and non switched supplies come from same fuse/MCB I have come across one installation where someone had separated the emergency and standard supply so if trip went the lights would not come on.

Sometimes the emergency and non emergency fittings do have separate supplies so a key switch can be used to test the emergency lights while leaving the non emergency powered as normal. Even in some places the emergency lights have been split into two banks so one at a time can be tested and other bank would still work if there was a power failure during the test.

 

[mte29]

Thanks for your quick and helpful replies. The setup will be that they are switchable lights. Firstly can anyone recommend which key/test switch to use?

My main point of confusion is do the EM's have to be linked to the normal lighting circuit or do they have there own circuit breaker and circuit?

Thanks

 

[ColJack]

Only issue there is you need one switch per unit and can't (unless you're feeling inventive with relays) have a common switch live.

on what are you basing this claim?
you just wire them like any other commoned lights..
as long as they are on the same circuit then it's no different to having 2 walls lights off one switch..

 

[ColJack]

Thanks for your quick and helpful replies. The setup will be that they are switchable lights. Firstly can anyone recommend which key/test switch to use?

any will do, they will likely be grid switches..

My main point of confusion is do the EM's have to be linked to the normal lighting circuit or do they have there own circuit breaker and circuit?

yes.. either or..
they can have their own circuit or be included with the normal lighting circuit.

 

[Spark123]

Only issue there is you need one switch per unit and can't (unless you're feeling inventive with relays) have a common switch live.

on what are you basing this claim?
you just wire them like any other commoned lights..
as long as they are on the same circuit then it's no different to having 2 walls lights off one switch..

No you don't, they cannot be wired directly with a common switch live.
The fact I installed some has a slight bearing on my claim......

 

[mte29]

Thanks Coljack. Having the EM's on there own circuit will be easier, but if i do this and the power supply to the main lights fails the EM's will not come on.
Is it relying on somebody switching them on? Or do the EL's have to lighted at all times for this setup?

 

[dextrous]

Thanks Coljack. Having the EM's on there own circuit will be easier, but if i do this and the power supply to the main lights fails the EM's will not come on.
Is it relying on somebody switching them on? Or do the EL's have to lighted at all times for this setup?

deleted comment - misread

 

[Spark123]

Thanks Coljack. Having the EM's on there own circuit will be easier, but if i do this and the power supply to the main lights fails the EM's will not come on.
Is it relying on somebody switching them on? Or do the EL's have to lighted at all times for this setup?

Maintained with switch lives relies on them being switched on unless they are on the same circuit as the local lighting. Maintained with a permanent link in will be on all the time.
I am thinking you are mixing up maintained and self-contained??

 

[ColJack]

Thanks Coljack. Having the EM's on there own circuit will be easier, but if i do this and the power supply to the main lights fails the EM's will not come on.
Is it relying on somebody switching them on? Or do the EL's have to lighted at all times for this setup?

given that you are going for maintained ones and that they will be switched on with the main lighting then if the main lighting fails you'll still have the emergencies on anyway..
if they aren't decorative ones like the main lighting, then you probably don't want them on all the time anyway..
in which case you DO need to wire them to the main lights so they come on if those fail..

I've installed many myself also.. in offices..
they are just wired in with the rest of the lights and swithched in banks along with the regular lights.

the "maintained" bit is just like a regular light..

if your comment was specific about exit lights, then they shouldn't be switched off anywy should they?

 

[Spark123]

I don't see the point in leaving them running in a place when it is unoccupied.

 

[dextrous]

I don't see the point in leaving them running in a place when it is unoccupied.

Can't you set them up with PIR's?

 

[Spark123]

Not really - they have to be visible to all people in certain premises when it is occupied.