Electricians

[twodogsfred]

Hi

Could someone tell me what the difference is between 'maintained' and 'non maintained' emergency light fittings..


Thanks

 

[seco services]

post in the electrics forum

 

[Spark123]

Maintained = on all the time or switchable on/off. Illuminates on power failure.
Non Maintained = normally off and illuminates only when power fails.

 

[Taylortwocities]

Non-maintained - The emergency light units only illuminate in the event of a mains failure.

Maintained - The emergency light units are illuminated at all times using the same lamps for both normal and emergency operation.

Sustained - The emergency light units are fitted with two lamps or two sets of lamps. One of which operates on mains 240V AC supply, the other which operates from the battery supply in the event of mains failure. It is basically a non-maintained system with the addition of mains lamps which should be illuminated whenever the premises are occupied.

 

[333rocky333]

maintained, lit 24 hour
Non maintained, lit only on power loss to fitting

Most signs above doors would be maintained.

 

[ban-all-sheds]

And most ones in people's houses would be sustained.

Sustained - The emergency light units are fitted with two lamps or two sets of lamps. One of which operates on mains 240V AC supply, the other which operates from the battery supply in the event of mains failure.

Sometimes there are just lamps, all of which operate on the supply, one of which comes on if the power fails, i.e. not a separate lamp which only comes on when the power goes.

It is basically a non-maintained system with the addition of mains lamps which should be illuminated whenever the premises are occupied.

That's an interesting one. Why is that?

Assuming we aren't talking about an exit sign, or escape route sign, i.e. just a light to drive away the darkness, why would it have to be on whenever the premises are occupied if there isn't always a need for artificial lighting?

 

[Taylortwocities]

My understanding is that these would be used in situations such an external escape stairs in sleeping accomodation where, at night, evacuation is required without necessarily a power failure of the local lighting circuit.

In normal mode the stairs are lit (sometimes controlled by PIRs).

 

[plugwash]

maintained, lit 24 hour

I was under the impression that maintained fittings had a switched live input so you could turn them on and off when the mains is ok.

 

[electronicsuk]

maintained, lit 24 hour

I was under the impression that maintained fittings had a switched live input so you could turn them on and off when the mains is ok.

Some, but not all.

 

[Spark123]

Yep, some of the eterna ones come with a link which makes the fitting maintained 24hr, removal of the link makes it non-maintained.
It is possible to fit a switch but only one switch directly from that fitting is possible without use of relays.

 

[333rocky333]

maintained, lit 24 hour

I was under the impression that maintained fittings had a switched live input so you could turn them on and off when the mains is ok.

A true maintained to me is on 24 hours and only has LNE connection.

Some have a seperate terminal for a switched live, but the original plan was that they should be switched on while the premises was occupied.

Certain places like them constantly on to make you aware of the exit prior to an event.
There could also be incidents where visibility is low and there is no power loss.

A sustained fitting was made for switching on/ off with the benifit of not wearing out the lamp required for emer use.

Fittings should be labelled as to what they are, but seems chaos now as maintained are being used as non maintained by leaving the link out.