replacing vacuum time lag switches with electronic ones

[sparkybird]

Hi everyone

Wondered if someone with more knowledge than me might be able to help!

Have a long standing problem with existing vacuum time lag switches getting damaged by kids in a block of flats so that they either stick 'on' or the push button falls out completely. I wondered if electronic ones might be a bit less prone.. (hoping).

The lights they control are 7 x 38W 2D emergency maintained. The existing switches are two wire (no neutral) and it would be difficult and costly to change this. All switch lines are wired back to a contactor:

http://www.rbstaronline.co.uk/acatalog/info_HAGES220.html

As I understand it I could use these switches:

http://www.tlc-direct.co.uk/Products/DNTLSW10.html

Togther with a capacitor for PF correction as the loads are under 40W each

http://www.tlc-direct.co.uk/Technical/DataSheets/Danlers/DNCAPLOAD.pdf

Is that one capacitor per light? (Sorry if this is a dumb question). I've not fitted one of these before. Do I need to worry about the battery?

Do you think the electronic timer route is wise???

Wish I'd paid a bit more attention to this bit at college....

Thanks in advance

SB

 

[Spark123]

Not sure on this - if you have more than one master type switch connected in parallel I take it you need a 40w load for each?
A contactor coil is a very small load, the capacitive loads (not for powerfactor correction), probably just has enough impedance for enough current to flow to power the switch, i.e. a dummy 40w load.
As the lights are switched via the contactor the switches will never see the loading from the lights.
There are slave switches available but these may need the wiring changed to accomodate.

 

[flameport]

You could use those switches, however they are expensive and can be damaged just as easily as the vacuum ones.

Another option is to fit a timer module next to (or instead of) the contactor and use standard retractive switches which are less likely to be damaged (but much cheaper to replace even if they were).
http://www.fastlec.co.uk/timeguard-elpa8-staircase-switch-p-5912.html

 

[sparkybird]

Spark 123 - thanks for reply

Flameport - MARRY ME!!

Fantastic suggestion - thank you.

Just to check -
1. replace existing switches with these
http://www.tlc-direct.co.uk/Products/MKK4878P.html

2 Replace contactor with the timer one you linked to. Does it matter that the timer is only single pole?

I noticed that the max switching for this is 2300W of incandescent, 1300VA fluorescent or 100W of L.E. lighting. So as I have 266W of lighting, I should be OK.

Thanks again for help

SB

 

[flameport]

yes, those are the switches, and you can remove the contactor as lighting load well under the timer rating.

Won't matter about single pole, the contactor should only be controlling the switched live to the light fittings (otherwise the emergency batteries wouldn't charge unless the light was on).

The timer connections are just L&N permanent supply, switched live in (from the switches) and switched live out (to the light fittings)
Diagram here: http://www.fastlec.co.uk/images/product_pdfs/timeguard/elpa8.pdf
yours is probably option 4.

 

[sparkybird]

Thank you so much for you assistance - a really good and cost effective solution

Sorry I got a bit carried away in my praise for you!

SB

 

[bernardgreen]

Take care Flameport.

This young lady may only be after your skill and knowledge and tool box ( maybe )

Flameport and Sparkybird Ltd Could be a good marriage....

 

[sparkybird]

Damn, I've been rumbled...

Better get a quick divorce from Mr Sparkybird!

SB

 

[333rocky333]

If you have a contactor in place I would keep it and use the delay timer just to work the coil, any fault on the light circuit will then not damage the unit, and the lower load may make it last longer.

Also is that timer electronic, some are mechanical and noisy.
Merlin gerin do a delay off electronic timer as well.

 

[sparkybird]

Thanks rocky, that sounds like a good idea as the contactor is already in place. The switching all happens in a cupboard under the stairs in the entrance hall, so noise it not an issue!

Thanks again everyone for replies

SB