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Emergency Light Test Switch.

Zoomup
Is it o.k. to use a non switched fused connection unit as an emergency light test switch? If not why not?


Z.
  • 0
    Zoomup:

    The emergency light testing can be combined with the 6 monthly R.C.D testing. I have never known a M.C.B. wear out due to regular switching off and on again. I know a church hall that uses only its Crabtree brown M.C.B.s as functional switches to switch its fluorescent lights on and off as there are no light switches. They have done this two or three times a week for over 50 years and the original M.C.B.s still function well.


    Z.




    Well I hope that has been picked up on an EICR as a recommended improvement!


  • 0
    jbrameld:
    Zoomup:

    The emergency light testing can be combined with the 6 monthly R.C.D testing. I have never known a M.C.B. wear out due to regular switching off and on again. I know a church hall that uses only its Crabtree brown M.C.B.s as functional switches to switch its fluorescent lights on and off as there are no light switches. They have done this two or three times a week for over 50 years and the original M.C.B.s still function well.


    Z.




    Well I hope that has been picked up on an EICR as a recommended improvement!




    These are they. Crabtree C50 type.

    50/05 - Crabtree C50 5A MCB type C 4.5kA Single Pole Miniature Circuit Breaker (brown) (sparksdirect.co.uk)


    Z.


  • 0
    I have never known a M.C.B. wear out due to regular switching off and on again. I know a church hall that uses only its Crabtree brown M.C.B.s as functional switches to switch its fluorescent lights on and off as there are no light switches. They have done this two or three times a week for over 50 years and the original M.C.B.s still function well.

    What's that phrase financial people like to use - something like 'past performance is no guarantee of future returns' - likewise just because the old fashioned built-like-a-battleship MCBs were good in some respect is no guarantee that today's 'value engineered to a micron of the product standard's minimum requirement' devices will be the same.


    I've come across several failed (relatively modern) MCBs - and while I've not been able to tell what the cause of the failure was, I can't help thinking the extra mechanical wear and more arcing could help.


       - Andy.
  • 0
    I'm surprised to hear of those MCBs used for flu lamp switching I was told on no account use MCBs to switch that type of load because the inductive voltage kick can cause flash overs I guess older gear is built better as said above. I know that trip switches can become less reliable with frequent use. We had one at my old work which was tripped by an overload maybe 10 times a week and it soon got oversensitive thats a bit extreme I know but it may start to be an issue if they are used for lighting testing
  • 0
    A question I never had an answer to, I fitted a self testing emergency light in a utility room over a consumer unit for the managing director of the company that manufacturers that make them, I asked him if a self testing emergency light needs a test switch, he laughed and said he didn’t know and he would ask their technical team.


    I fitted a test switch to the self testing emergency light, but never heard if it was needed or not. I did however have quite an involved discussion about remote monitoring of emergency lighting with the MD, the self testing lights aren’t suitable for hotel bedrooms and the like as they can turn themselves on at inappropriate times, however systems can be set up to monitor the emergency lighting remotely from the manufacturers HQ and the client gets an email to tell them when there’s an issue that needs resolving.
  • 0
    A story I have told several times on this forum.


    The retired rep from one of the wholesalers got me to go and do some work in a theatre where he does the stage lighting.


    I phoned him and said there was a problem, because I had turned a lighting circuit off and I was in darkness, because the emergency lighting had not come on.


    He said “Oh no! Not again!” I enquired what the previous issue was and he said the licensing officer had been to do an inspection and whilst standing in the bar he gave the instruction to turn the general lighting off at the MCBs in the distribution board to test the emergency lights, the bar manager said they had EM test switches behind the bar and used those, but the licensing officer was adamant that he wanted the lights to be isolated at the distribution board. When the emergency lighting did not come on because they were supplied from a different circuit to the general lighting he issued an enforcement notice.


    Generally licensing officers don’t trust electricians to get things right and may not use a test switch opting to kill all the power to the lights instead at the distribution board.
  • 0
    I have just fitted a few self testing emergency lights which are not remotely monitored and have a question. They give a warning flash of their indicator LEDs prior to a test but after they have done  their full three hour test which could be at any time during the day or night how do you safely occupy the room if you don't know if the battery has recharged or not?
  • 0
    AJJewsbury:
    I have never known a M.C.B. wear out due to regular switching off and on again. I know a church hall that uses only its Crabtree brown M.C.B.s as functional switches to switch its fluorescent lights on and off as there are no light switches. They have done this two or three times a week for over 50 years and the original M.C.B.s still function well.

    What's that phrase financial people like to use - something like 'past performance is no guarantee of future returns' - likewise just because the old fashioned built-like-a-battleship MCBs were good in some respect is no guarantee that today's 'value engineered to a micron of the product standard's minimum requirement' devices will be the same.


    I've come across several failed (relatively modern) MCBs - and while I've not been able to tell what the cause of the failure was, I can't help thinking the extra mechanical wear and more arcing could help.


       - Andy.


    The mechanical operational life is expected to be.......?


    Look

    https://cdn.yesss.co.uk/documents/59211.pdf


    Z.


  • 0
    Normally the self test is not a full 3 hour run down, rather the NiMH runs it down for about 30 mins, and verifies that the cell voltage drop is 'on track' not to fail in the declared time. The larger lead acid units are tested by verifying internal impedance from a very short high current discharge - a higher than expected voltage droop indicates loss of useful plate area, and reduced capacity, While both methods are a bit approxmate, usually it is pretty good, within about 10% of a proper capacity test.

    It is more important in such cases to re-fit the right sort of replacement battery, as a change of chemistry, or the use of a gel lead acid instead of liquid filled a glass fibre mat can confuse the self test, either into warning when it should not, or worse, not warning when it should.


    Mike
  • 0
    mapj1:

    Normally the self test is not a full 3 hour run down, rather the NiMH runs it down for about 30 mins, and verifies that the cell voltage drop is 'on track' not to fail in the declared time. The larger lead acid units are tested by verifying internal impedance from a very short high current discharge - a higher than expected voltage droop indicates loss of useful plate area, and reduced capacity, While both methods are a bit approxmate, usually it is pretty good, within about 10% of a proper capacity test.

    It is more important in such cases to re-fit the right sort of replacement battery, as a change of chemistry, or the use of a gel lead acid instead of liquid filled a glass fibre mat can confuse the self test, either into warning when it should not, or worse, not warning when it should.


    Mike


    Far too clever for a simple soul like me. :( 


    I have just read the instructions and the emergency lights only do the full test, that say it will take three hours, at a random time in the 24 hours after commissioning. After that it does its short checks weekly and requires a button on the light to be pressed to instigate a full test at a random time in the following 24 hours. 


    The Emergency Exit signs are the same make and have a similar commission and short test process but also say they will do the full test every 12 months. They do not have a button to press to perform the full test at another time. 


    The emergency light test switch, key operated :) ,  will have to be used to test both types as some of the emergency lights are mounted over four metres from the floor. 


    Am I alone in thinking that while trying to make things simpler they become more complicated?


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