Overview of emergency light fittings and using a key operated switch to disconnect power for test purposes. Patreon: / jwflame Contact info, sending stuff in etc.: xo4.uk/?YTT
I have also seen key switches used for other "maintenance personnel only" switches, such as forcing on or off lighting that is otherwise automatic when testing or replacing bulbs, or as regular light switches in areas accessible to the general public. It helps that in my country, key switches fit the same boxes as regular switches, allowing trivial change between types.
Maintained is less common than Non-Maintained or even combined here in the US. Combined is used where no additional fittings are desired, in that case a test button does protrude into either the lamp cavity or out of the base depending on the fitting. A US type fluorescent combined unit contains two separate ballasts (one standard and one emergency) with one or more lamps. Neutral and earth are combined from both ballasts. The line from the emergency ballast is equal to the Line terminal on UK combined, the standard ballast line is equal to the switched line. In this system it is important to note that the emergency ballast simply passes through power from the standard ballast to the emergency lamp or lamps under normal conditions. Under emergency conditions the emergency ballast starts up and switches the lamp or lamps from the (presumably interrupted) standard ballast connection over to the emergency ballast. When mains power is restored to the emergency ballast it will switch the lamp back to the leads (either energized or not energized) standard ballast.
emergency light fixtures are now pretty much the final place you can find nicad batteries, apparently because they can be constantly charged at very low currents, no sophisticated charging circuit, and the manufacturers are very resistant to upgrading the technology. even cheap power tools have moved on.
whats interesting is iv'e worked in maintenance for years and i never really knew HOW these lights worked on the inside, usually when it goes bad you just pull the old battery/ballast out and replace the lights with wire for wire so its nice to have a bit of a breakdown for what i end up repairing. our company only uses one brand and type of lights so we are just told pull out and put in a new one so thers not really any question of what to wire and hook up.
Great vid John. Glad you made that point at the end about switch emergency supplied only, just last night we tested a building that cuts all lighting on the key!
Somebody probably thought they were being really clever and thought the test switch was to test what the building would look like with just the emergency lights on. Never doubt the initiative of an idiot.
What I tend to do John is operate the key switch at the beginning of my EIR testing or other maintenance and check the light output after 3 hours, and just replace any fittings that have weak batteries as it is normally cheaper and quicker than just replacing batteries alone.
In Germany do you must change the battery every 2 years or if they not works more - do this what first happend. So the law for all emercency lights and alarm boxes how works with batteries too. Of course at your private house do you can do what you want. In Thailand they not have a law same this - wonderful to see in commercial buildings where power breaks at monsum or thunderstorm. Some parts then very dark ... looks then same the Hospital in game Silent Hill.
Big fan, most house wiring switches only switch on leg of the the mains. It´s a bit redundant to switch the negative leg as well. If you need to install emergency lighting after construction and want to use an existing installation this should be kept in mind.
Normally UK domestic lighting installations are easy to convert to emergency lighting as there is usually permanent and switched live connections at the light fitting. The only problem is wiring a test/key switch (a toggle switch added to the fitting is an easy solution if possible).
Phenomenal video John, much appreciate your efforts. Thank you! Is it possible for you to do a video on how to test the lights when wired in a communal area and are connected to day key switch/ time clock please.? Many thanks!❤
+John Ward You can't use the term Bennies! During the Falklands war, the UK troops referred to the local inhabitants as Bennies. They were told by senior officers that they were to cease this terminology as it was insulting, so they did... They started calling them Stills... When asked why, the reply was "Because they's still F*cking Bennies" :)
You forgot to mention the term Benny was termed from the simple soul character in the TV show Crossroads. Therefore, in JW's defence, he was merely referencing this character to people that wire emergency lighting incorrectly. Though subjective, it is hardly a derogatory term. In fact, Bennie isn't even listed on Wiktionary's list of English derogatory terms!
I was assuming that JW's audience is in a demographic that is familiar with Benny From Crossroads! I was making a light-hearted jibe at the radical PC brigade... Perhaps I was a little too subtle! ;)
Hi John thanks for posting this vid, its cleared up my suspicion about a shop I attended the other day in regards to a TV gantry issue . This gantry has 8 x 50" TVs . All working with Server which streams video signal through it. The issue was when staff leave the building at night , they use this switch , which is that key type as shown in your video, and turns the lights off on the shop floor, plus its cutting the power of those TVs. Which to me surely they should be on a separate switch, and the lights shouldn't be turned off via that switch?. When they come back in the morning and turn the switch back on. The lights take five minutes or so to kick in and these TVs are not showing a picture. The TVs all have a PC which is linked via network to the server which streams images back to the screens via HDMI. I've now requested an electrician to check this out as I believe this is wrongly wired. Surely that switch should not be serving a power circuit cutting power off to TVs? Kind regards Mike.
The switch probably operates a contactor, which itself can control multiple separate circuits. However it's not a good idea to just cut power to TVs and an PC, so some alterations would be advisable.
I dont work on that side of engineering but I do on networks and PC, I have some electrical knowledge as I studied when it was the 17th edition , I did the old City and Guilds 2330 level 2 and level 3, because I wasnt working with an electrician at the end of that period to finish off and do the NVQ part , I went on and done HND in electrical. , I went back to do the second year of it , but dropped out because my mother wasnt keeping well and I was finding it too much to study. Thanks for that John I did think , this wasnt correct but wanted a second opinion. Many thanks and a Happy New Year to you.
All your videos are top quality, thank you. Quick question, what’s the effect of swopping the phase wire and battery charge wire around? Effectively A and L1?
If I fitted maintained lights (always off ) and client asked for them to be constantly on could I simply put in the the link from permanent live into L1 ?
On the last part where you have an extra switch running to the SL. Could you still use the loop from the L to the SL to bypass the lightswitch instead of needing to remove that second switch?
I have seen an abysmally installed emergency exit sign in one building, it was the blade kind of exit sign, and it was facing the wrong way, so it just looked like a green rectangle, without the exit sign legend. But worse, it was a non-maintained sign, and the power was arranged so that when the normal lighting in the area was switched on, the sign was charging, and when the lights were turned off, the power to the sign was disconnected, and of course should turn on. As it was above a final exit, it should be permanently illuminated. The same building also had at least one exit sign with the legend upside down, but at least that was the proper maintained arrangement. How anyone could possibly be that stupid is a mystery to me.
Excellent video John, thank you. I have 7 emergency lights which have various combinations of 'not working'. I think I am at the point of just buying new LED versions rather than trying to source batteries for my ancient fluorescent ones. Do they have a BS or EU rating I need to be looking out for? I'm in Scotland, but I think the standards are the same as England (all based on EU)
Do you know where I could order some wire in order to extend the mains wires to the terminal of a fitting? I.E for those situations where the mains wires don't reach the light and need to be extended using other wires?
The little one can reach the light switch from their cot. Rather than move the cot or the light switch, can I replace the standard switch for a key operated switch? The current switch has 2 connections only with a single wire in each, but these key operated switches seem to have 4 connections. Do I just wire up to L1 and L2 to make it operate on/off via the key switch?
Hi John, thank for the most easy to understand videos on you tube. I have a quick question for you, maybe you can help: Most of the emergency light fittings when you put them on test mode (you operate the key switch) have the small LED turned off - however not all of them unless you trip the breaker as well. How is this working? I'm a bit confused
If the key switch doesn't control them they have been wired incorrectly. Those which stay on have been connected directly to the circuit without any switch.
Dear Mr. Jw 1st of all, I'd like to thank you for you posted videos, they are so useful and I learned a lot of them. Now I've a question that difficult to me. But I'm sure it's so easy for you. Q: what's the standards for electrical cable used for DC current? And referring to which B.S.
I have never seen a test key like the one you used, was it CED or something? I have a site that uses the old MEM key switches, they are wafer thin switch keys, thinner than MK keys and I can't get a new key for them. I Googled the switch type which is MEM Spectra F8027EL. The slot is incredibly narrow, I reckon I'll have to put a newer type of MEM test key on a bench grinder to lose some fat so it will fit in the slot. I bought a couple from ebay and they are both exactly the same and too thick. Most annoying. 😖
Thanks a lot Mr. John ward. My Question is: Emergency Lighting belong Lighting System or Fire alarm system? i.e. Shall we connect it to lighting system or F.A.S. or (may be) to a seperate feeder from mains power. Thank you very much in advance. waiting for reply.
@@jwflame Sabah Hassan 8 minutes ago Execuse me Mr. John, but the emergency lighting, exit lighting , exit sign , ...etc, are actuated & work also in case of fire occurrence.
John, should the permanent live feed to emergency luminaires be from a separate MCB in a CU? or can they be fed from the same one as the lights in the area the emergency luminaires cover? If fed from a separate 'Emergency Lighting' MCB, then they won't illuminate if the MCB for the normal lights trips, thereby leaving the protected area in darkness.
Are you allowed to use a standard light fitting as an emergency light powered by an external UPS provided the cabling from the UPS to the lamp is fireproof?
Thank you for sharing Sir. What would you advise on wiring Em lights on existing lighting circuit? It occurs to me that it would be the case of aBorrowed Neutral isnt? Is it allowed/ any ways around it? Thank you
In UK do you must installing emercency lights in houses? Or only owners in rented houses/apartments? Do you know if you have fire inside, the smoke is possible very thick, so the emercency lights should at down at the floors. If failed the power often it is better to repair the maistake power line ...
They're generally only used in commercial premises or communal areas (stairwells etc) of apartment blocks etc. There's no requirement to have them in domestic premises, but I like to install them. I have one in the kitchen, and if there are stairs, also there, they're the 2 areas where being plunged into darkness could be very dangerous. A domestic garage used as a workshop would be a good place to install one too-
Most homes do not have emergency lighting installed. But most flats have them in the stairwells. I live in a semi-detached house, and installed a non-maintained luminaire on my bedroom ceiling just for the sake of it though. I picked one up from Yess electrical for less than £20. I am also thinking of using a switchable maintained one for the porch light too though. Seems like a good low energy general use lamp, plus the exit is lit in a power failure. Very handy things in my opinion.
+TheChipmunk2008 Yes in Germany commercial bildings must have emercency lights too. Private buildings not. Here in Thailand private buildings from richer people have a battery box with two lights installed in the rooms, but the most poor people have not. For stairs is that a good idea these days we have leds they are small invisible if them are off.
@@TheChipmunk2008 after the exit route and any stairs next favourite place to put one is illuminating the consumer unit - you might then see why you've been plunged into darkness. :)
I'm suprised to see that non automatic test switches are still alowed there in the UK, they have been banned here in Au for years as drongos' can leave the switches off after testing rendering the entire system useless, so, 90 Min test timers are the legal requirement here. I like the term combined, we call those fittings "sustained", combined sounds better.
The auto test switches can be obtained here but are rarely fitted. The standard for emergency lighting just requires that there is some means of disconnecting the supply to simulate mains failure.
Good morning JW, it started out that way here too until someone forgot to reset the switch for an emergency lighting circuit in the staircase of a building they were testing, unfortunately that resulted in several people being injured during an actual blackout and a law suit thereafter. No one noticed the circuit had been left off because the maintenance switch leaves the general lighting operative and unless you go around looking for charge indicators on non maintained or sustained fittings, well.... So the regulations were changed after that. Keep up the great work, rgds M.
Many places here still use the circuit breaker as a switch to test the e/l. Not ideal, but at least it shows if the circuit is left off. To me, the ideal would be an e/l test switch killing the power to the lighting circuit completely It's obvious if it's left off... and accurately simulates a failure
why are some circuits wired in 3 core and earth John if all you have to do is link across to make it a maintained fitting .normal twin and earth would suffice .or have I missed something
If you have a combined fitting, that acts as a normal light (as in on/off when necessary), but is also an emeg, you'd have a perm live to the battery from a key switch, and then a switched live to the normal side of the fitting
My building has a 3rd type of lighting: The emergency lighting only operates when the light switch is in the ON position. So if the power fails when the light switch is off nothing happens (so they only work during the evening). What is this type called?
Incorrectly installed - the idea is that they always illuminate when power fails, people stumbling around in total darkness looking for a light switch is not desirable.
So if you had a key switch and a normal switch right next to each other, would you just link the live out from key switch to common terminal in normal switch?
Yes. You'd link the switchline / load from the key switch to the common of your normal switch. The key switch is then essentially just switching on and off the feed to the normal switch.
@@nathanhedgeley8016 so if you didn't want the normal lights off the key switch just come out of incoming supply side of key switch to common of switch instead ?
@@sbmorris2k6 Yeah that's right. So then the key switch will only turn off and on the emergencies and your normal switch will only turn on and off the switchline to your normal lights. That means when you turn the key switch into test mode your normal lights will stay on and only your emergencies will be isolated.
PIRs have L, SL and N, those connect to the same terminals in the light fitting. L&N are the permanent power supply, SL is used to switch the light on and off.
Hi john. Found the emergency light video really interesting. Would you be able to do a video on how the battery in emergency light are connected and how they are charged. Also with non maintained light what keeps the light off until power is disconnected. Thanks Jon in Swindon U.K.
I don't understand why the terms 'maintained' and 'non-maintained' are used. I can't see how one is maintained and the other isn't at least in the sense of how I understand something being 'maintained' (kept in good working order) ?
Yeah I get that, but it seems a poor choice of word. It implies to those not familiar with how the word is used in relation to emergency light that the 'non-maintained' lights are well........not maintained! Surely a more technically descriptive word of the difference between the two types would be better.
I think it makes sense. If you think of maintained in the fact that because the light is permanently on it will need to be maintained as in changing the lamp. Therefore non maintained does not require maintenance as it the lamp shouldn't fail as its only on when the power is off. I find that way is easy to remember it mate.
Maintained is the correct word. The usage is different from the one you suggest, i.e. "keep (something) at the same level or rate:" rather than "keep (something) in good condition". Like 'maintaining a constant flow', for example
