Auto lighting control

[john.bradgate]

Can anyone help please?
I am currently designing a lighting installation for a steel modular switchgear housing. The module is divided into three seperate rooms each with it's own light circuit. The module is classed as "Un-manned" and as such the client has requested using PIR Sensors in place of conventional light switches, in a bid to prevent lights being left on. Additionally he has asked for an override switch (clever man).
From researching on the net I dont think PIR's are the answer since maintenance engineers are liable to be stationary with in the module for long lengths of time and with the height of the installed equipment, complete coverage will be difficult to achieve. Personally I feel that the override switch is a non-starter, given the clients overall aim.
I am looking into using a "Delay off" switch on each circuit - to give maybe 8 hours light - and then automatically turn the lights off. However this is not a concept that I am familiar with and would welcome any advice anyone can offer.

 

[Griffin]

What I would do is go back to the client explain the benefits or drawbacks of each option.

Sounds like you may need a couple of PIRS (for coverage) and off timer per bay

Ultimately its up to the client just make sure they understand what is being installed.

Regards

G

 

[john.bradgate]

Thanks for the advice. Can you give me any advice / info with regard to integrating the delay-off timer into the lighting circuit, as I said previously, it is not something I have used in the past. From my limited understanding, the delay wont start until the switch circuit is de-energised - so would I need to replace the light switch with a "momentary" type pushbutton.
Best regards, John

 

[Griffin]

Hi,

Depends on the type of timer you fit.
For example if you had a switch/PIR the timer would start once the switch was opened. (timer would need a permenant supply).
You can buy timers that fit inside CU enclosures or you could build a small panel to cover all you lighting.

Have a look at the atatchment for more timer info from the RS website. (There are thousands to choose from)

http://docs-europe.electrocomponents.com/webdocs/0bd6/0900766b80bd619e.pdf

Hope this helps

G