EMERGENCY LIGHTING

[hoodie786]

hi can some one please tell me the difference between maintained and non maintained emergency lighting, thanks

 

[ricicle]

Non-maintained = lamp only lit on mains failure.
Maintained = lamp can be switched on when mains on and will light on mains failure.

 

[PrenticeBoyofDerry]

Maintained:
The same lamp is used by both the mains and the emergency backup and will/can operate continuously. The lamp is supplied by an alternative source when power fails.

Non-Maintained:
The lamp only operates when there is a mains failure, as it is then connected to the battery supply.

 

[securespark]

There is also sustained. They have lamps lit by both sources, mains and back-up.

 

[Taylortwocities]

There is also sustained. They have lamps lit by both sources, mains and back-up.

Usually two separate lamps, I believe?

 

[Spark123]

Yep, at least one normal and an emergency
There's also distributed systems with slave luminaires

 

[securespark]

There is also sustained. They have lamps lit by both sources, mains and back-up.

Usually two separate lamps, I believe?

Yes, sorry. I omitted the word "separate".

 

[Risteard]

There is also sustained. They have lamps lit by both sources, mains and back-up.

"Sustained" is no longer defined by BS 5266.

 

[ban-all-sheds]

So what's a luminaire with 2 lamps, normally mains powered, and on loss of power one lamp comes on, powered by the battery?

 

[canduit]

They are called, perhaps wrongly, maintained.

 

[333rocky333]

same as a four tube module in a shop, only one of the tubes works from the battery, yet the fitting is still called Maintained

The problem with a maintained fitting is that due to poor maintenance the single 8w lamp has usually failed from normal use and in event of power failure there is no light due to the failed lamp,

A true two tube sustained fitting only ever had one lamp lit from the mains, the purpose of which was so the back up lamp would not deteriate from unneccesary use
They were effectively a standard mains light and a non maintained light combined in a single unit.

 

[333rocky333]

deleted

 

[RF Lighting]

I recently fitted some similar fittings. They were HQI downlights in an office, but they also had a 20W capsule lamp in the same fitting to provide emergency light.