This is 24V and need to cable up between closer and switched supply.
I have checked the supply does go off with a fire alarm!
What cable should I use? I'd rather use something other than mains cable to differentiate between mains and ELV.
I used telephone cable. I ran six pairs from the wiring centre to the front door, and just used one of those.
The current draw isn't great (on mine, anyway) and the duty cycle is low.
Many thanks for the idea.
Its only a short distance. I would have preferred to have exported an earth as well, given the cases are metal, and the transformer of unknown origin.
I was looking for shielded cable or screened twisted pair, then it dawned on me I can make one conductor earth as well as 0V return!
What current does the solenoid use though? Brian
Fire alarm cables are usually red, I don't know if the door closer wiring has to be too, but I don't think it would do any harm.
Screened, available in 2+E and 4+E. Sold per metre.
Owain
I think he is referring to an electromagnetic door holder rather than a catch so the duty cycle is more or less 100%. The power consumption is still low though - typically only 1 or 2 Watts so almost any cable would be suitable.
That's a good question. I could measure the resistance of one.
I assume it can only take a couple of watts.
Yes, it will be permanently on, even when the door is closed, and only off where there's a fire alarm.
Either way we are talking sub-Amp.
Given the solenoid is fail safe, and power disconnected on alarm, I don't feel the need to use fire resistance cable. However it would be smart to make it easily distinguishable from other cabling.
FWIW, a while back I helped my BIL (a builder) release and re-connect the cabling to a door entry system from a wall he was removing for a company. The 'fail - safe' door bolt along with the alarm keypad were run (some distance) to the reception though a multi core cable, the conductors not much bigger in wire gauge than Cat5 / telephone.
YMMV etc. ;-)
Cheers, T i m
24V at 1 to 2W so 40 to 80mA.
Peter Parry wrote in news: snipped-for-privacy@4ax.com:
Intrigued - how come so little?
Guess lots of turns!
A solenoid is not like a transformer, where I is purely limited by the solenoid coil resistance.
The solenoid doesn't hold the door open directly - it just holds a latch inside the closer which stops the closer operating.
The solenoids which attach to the wall and are no part of the door closer mechanism probably use more.
Owain
The figures given were for a solenoid attached to the wall.
This is a solenoid on a wall, separate to the closer.
HomeOwnersHub website is not affiliated with any of the manufacturers or service providers discussed here. All logos and trade names are the property of their respective owners.