Timer for Door Entry System

[johndo78]

We live in a traditional flat with an old style door entry system (buzzer box at the door and phone handsets in the flats).

The timer (that allows the service buzzer to work for the post man) on the entry system has stopped working and it needs replaced. It looks as if it is just like the sort of timer that you get on old hot water systems (clock dial that rotates and you push plastic pins in to fix the on/off times). Any idea where I can get a replacement timer??

I've tried B&Q and the only ones I could find were for 3 pin plug sockets for lamps or other appliances that need timers or electronic ones for central heating systems (which are quite expensive £50+). Found a few options at Screwfix which are lighting timers (digital with 7 day set up and various on/off options) - would this sort of thing be suitable (they only seem to cost £15-20)?

Cheers,

John

 

[hairyben]

local electrical wholesaler should sell you a 24hr mechanical (immersion heater) timeswitch for about a score.

 

[JohnD]

I prefer the mechanical timers to the electronic ones, as it is so obvious how to reset them after a power cut or for Summer time.

Yes, an Immersion timer, or a Boiler timer would do (bolier timers are usually 3Amp max, which should be plenty. Immersion timers are usually 16Amp max)

 

[breezer]

look again in both screwfix and B & Q you want imersion heater timer as these USUALLY have clean contacts (not connected to anything) so would be ideal for what you want

 

[hairyben]

oh yeah, good point breezer, often known as "volt free switching"

 

[johndo78]

Would something like this do the job??

http://www.screwfix.com/prods/89388/Electrical/Timers/Mechanical-Immersion-Timer-24-Hour

 

[johndo78]

Would something like this do the job??

http://www.screwfix.com/prods/89388/Electrical/Timers/Mechanical-Immersion-Timer-24-Hour

Ok, bought one of these yesterday and it seems to be fit for the job. However, the wiring set up is slightly different to the one that I'm replacing.

In terms of wires, I have live and neutral mains input wires which go to the live and neutral input terminals on the timer (checked with a multimeter and the power is getting to the timer fine).

Also, there are two wires from the service button on the door entry system (like the wires that come out a phone point - very thin and multicoloured). I noticed on the old timer that neither of these wires was connected to the neutral output terminal - one was on the live output and the other on some sort of switched terminal on the live side. On the new timer I only have 2 outputs (one live and one neutral).

So, should I simply be connecting the thin service button wires to the live and neutral output terminals or should I be using some other arrangement of connections?

Cheers,

John

 

[hairyben]

Would something like this do the job??

http://www.screwfix.com/prods/89388/Electrical/Timers/Mechanical-Immersion-Timer-24-Hour

Ok, bought one of these yesterday and it seems to be fit for the job. However, the wiring set up is slightly different to the one that I'm replacing.

In terms of wires, I have live and neutral mains input wires which go to the live and neutral input terminals on the timer (checked with a multimeter and the power is getting to the timer fine).

Also, there are two wires from the service button on the door entry system (like the wires that come out a phone point - very thin and multicoloured). I noticed on the old timer that neither of these wires was connected to the neutral output terminal - one was on the live output and the other on some sort of switched terminal on the live side. On the new timer I only have 2 outputs (one live and one neutral).

So, should I simply be connecting the thin service button wires to the live and neutral output terminals or should I be using some other arrangement of connections?

Cheers,

John

NO!!!

you need volt free switching, or you can connect a relay to the timer you have. the timer will output 230v, your systems probably operating at 12v, = flash bang and smoke.

 

[Spark123]

It doesn't sound to me like it is volt free switching so no - you must not connect that to your door entry system which are normally extra low voltage.
Can you upload a photo of the old time switch? I'm thinking it will use L&N from the mains to run a small synch motor which drives the clock. The volt free switching is done on a small microswitch. I'll have a look in my garage shortly as I am pretty sure I might have one.

 

[Lectrician]

The grasslin timers are volt free, when you remove the copper link. They are often used for intercoms, and are available at most wholesalers - Wilts stock them.

Take a google for grasslin.

 

[Lectrician]

Googling finds me this:

http://www.alertelectrical.com/Gras...16a-24-hour-Immersion-Timeswitch-GRASTI24.asp

Ideal

 

[johndo78]

Thanks guys.

Just managed to get a better look at the old timer in decent light and it is exactly as described by Spark 123. There is a small microswitch marked on the wiring diagram.

I'll get myself one of the Grasslin time switches as found below.

Thanks again for the assistance.

 

[johndo78]

Got the Grasslin time switch last week, fitted it in no time at the weekend and everything now works like a dream. Thanks to everyone for your assistance.

 

[breezer]

go back and buy another one, keep it for when what you have gives up