Help wiring a Horstmann Centaur C11

Kashkai

My APT analogue timer died a few weeks back, well the timer part did as it still works when manually switched on/off.

I bought a digital Horstmann C11 as my parents have one and its worked fine for years. However I'm having some trouble figuring out the wiring as my APT has an earth lead, a live, a neutral and a "grey wire" which I'm presuming is another live?.

The Horstmann wiring diagram is like this:
http://www.horstmann.co.uk/downloads/ElectronicDocuments/Central-Heating/C17-InstallationInstructions.pdf

Can someone tell me which wire goes where and confirm that I have to bridge two contacts and also what type of wire will suffice for the "bridging". I'm competent enough to do the job once I know what I have to do in the first place.

Bruthal

Your link does not work, but i think the new timer has a L in and N in then has terminals 1,2,3,4
Terminal 1 does nothing according to the C11 diagram im looking at
Terminal 2 is the common, 3 is the Norminally closed and 4 is norminally open

Your APT had a live, neutral, and grey? Sounds like the grey is the switched live, is this a wire out of the APT or the wire leaving it then out to heating or whatever its controlling is grey?


Anyway i will assume this grey is a switched live,

Judging by your description,, try this - on the new timer, connect the live and neutral into the L & N terminals, then link the L to 2, and whatever the grey was connected to on the APT, connect this to 4 on the new timer.

Bridge with a bit of 1.5 brown should do, depending on what was being switched by the timer and assuming its a 10 amp MCB controlling the timer circuit. If its an immersion use 2.5 brown for bridging.

If the new timer has no earth terminal then put the earth into a connector along with other earth to the appliance if there was one from the timer, and/or onto metal back box of timer if it is metal.

M cebee

ya-that's it

must be a boiler-that thing won't be rated for 3kw

Bruthal

True yea i think 3 amps is all they are, never looked except at the contact layout.

Kashkai

One more question re. wiring this timer:-

I have two wall stats that control the two zones in the house by way of two separate motorised valves but these are operated completely independently of the old APT timer, i.e. I can switch on the boiler to heat the water if the two stats are turned off, and if I want central heating I turn the stats on, both times manually. Does this make a difference to how the new timer is wired?

Bruthal

Prosperous Dave wrote: »

One more question re. wiring this timer:-

I have two wall stats that control the two zones in the house by way of two separate motorised valves but these are operated completely independently of the old APT timer, i.e. I can switch on the boiler to heat the water if the two stats are turned off, and if I want central heating I turn the stats on, both times manually. Does this make a difference to how the new timer is wired?

It should still work as it was if your just replacing the timer as the old one was fitted, but the way its done these days is the timer switches power to the stats, and from the stats to the motorised valves. When the timer switches on, that gives a feed to the stat, and if the stat is closed it powers the valve. The valves have switches in them, and its these switches that bring on the boiler.

In your case you have 2 zones, and you could fit a hot water cylinder motor valve controling the hot water through the heating coil with its own stat, and for all the above a 3 channel time clock would be used.
So when any stat closes to call for heating, it will energise its motor valve which closes the motor valve switch to start the boiler, once the time clock is also calling for heat too.

I dont have any of it myself, one of these days i will get around to fitting a couple of valves. Much better control of the heating then.

Kashkai

Was going to wire up my new digital timer today but then I noticed that the wiring in place is grey, brown and black with a separate earth. What is what with regard to the grey, brown and black wires, i.e. live, neutral etc and where do they go on the timer diagram above.

Thanks

Bruthal

Brown black and grey are normally the 3 phase colours for the past few years now, if wiring was done in the house using them colours then it really must of been a cowboy like you said before. So unless you can tell us exactly how the brown black and grey where connected to the old timer we wont be able to say how to connect the new timer.

I know you described in the first post but you will have to say exactly what was connected to what in original timer now.

Bruthal

Maybe they just used a 3 phase cable for the heating timer control. Brown is probably the feed to old timer and black is neutral, so grey would be the switched live out, so it would be as in post #2 if that was the setup to old timer described in this post

Kashkai

Just looked at the wiring on the APT timer and its as follows:

Black into Port 1

Brown into Port 2

Grey into Port 3.

I've googled APT but can't find a wiring diagram on the net so I don't know what 1, 2 or 3 is, i.e. live, neutral etc.

M cebee

Prosperous Dave wrote: »

Just looked at the wiring on the APT timer and its as follows:

Black into Port 1

Brown into Port 2

Grey into Port 3.

I've googled APT but can't find a wiring diagram on the net so I don't know what 1, 2 or 3 is, i.e. live, neutral etc.

there's normally a label on the APT

N 3
L in 2
L out1
if memory serves

time to call a sparkie by the sound of it:)

Bruthal

It does sound like black is neutral in, brown is live in, and grey is the switch wire from your description. But cant be certain. Very simple for a sparks to sort it if he/she was there looking at it.

You could connect the black to neutral in of new timer, brown to live in, and link the Live in to terminal 2, leave the grey out for now, and switch on, if timer works ok then the black is the neutral by the look of it. Just test the brown to see its live when test the timer, and once your satisfied the timer is working, switch circuit off and connect grey to terminal 4 and test.

If you connected grey into terminal 4 and it happend to be the neutral you would have a short if the timer contact closed.

M cebee

robbie7730 wrote: »

It does sound like black is neutral in, brown is live in, and grey is the switch wire from your description. But cant be certain. Very simple for a sparks to sort it if he/she was there looking at it.

he said grey was port:D3-so grey would be neutral

get a sparkie dave before you get fried:pac:

Bruthal

M cebee wrote: »

he said grey was port:D3-so grey would be neutral

get a sparkie dave before you get fried:pac:

Yea which was why i suggested leaving the grey out in case of that, brown looks like live in, so which of the other 2 is neutral, grey by the sound of it if you think terminal 3 was neutral in the APT timer, i would`t know that myself. 230v may show up on a tester between Live-N and between Live-sw, so it may not be simple for the non sparks people to sort which is neutral.

Bruthal

Take a photo of the original timer showing the terminals and put it up, i see an ATP immersion one and the 3 terminals show 2 small black wires leading from the first and third terminals, so the L and N in are obviously into these 2 terminals, and the sw out is the middle one.

http://www.gil-lec.co.uk/products/Controllers/Timers/Immersion+Heater+Timers/For+Immmersion+Heaters+24HR+16A+230V/4123465648

Just to right of main pic is a thumbnail showing the back of the APT timer.
Is your one anything like that dave?

M cebee

i've wired hundreds

3 is neutral

they have a label showing the connections anyhow


cowboy alright when he didn't tape the ends -although even that wouldn't comply

Bruthal

Well were they the same as the pic i linked to, if 3 is neutral then middle is sw and 1 is live in. The first and 3rd terminals in that pic have the motor (black) wires into them so they are L & N, and middle is SW, unless yet again im looking wrong.

M cebee

robbie7730 wrote: »

Well were they the same as the pic i linked to, if 3 is neutral then middle is sw and 1 is live in. The first and 3rd terminals in that pic have the motor (black) wires into them so they are L & N, and middle is SW, unless yet again im looking wrong.

damn:pac:

3 neutral
2 live in
1 live out

M cebee

prob the neon you're looking at

Bruthal

I know, it may seem stupid, but why dont you tell him the answer then,

And in the pic how can terminal 2 be the live in (assuming the centre terminal is 2), It looks to me that if the centre terminal has the feed then no supply will be going to the motor when the timer is in the off position.

L & N should surely be into the terminals feeding the timer motor. I have wired dozens of them timers also, but i would still need to look at the diagram if i ever connect another one as i have not seen one in a few years now.

Im just curious thats all. Did you look at the pic to see what i mean?

Bruthal

M cebee wrote: »

prob the neon you're looking at

Yes thats a fair point alright.

Ok dave so it looks like Brown to Live in on new timer, and link this to terminal 2
And grey to Neutral of new timer
And black to terminal 4

And test it out.

M cebee

jeez i wasn't even reading the question

-i described the wiring of apt( he needs to transfer the wiring over )

i dont believe in giving specific instructions on wiring to diy'ers-no offence intended to dave:)

as i would feel responsible for any injury etc. caused

Bruthal

I think he is an aircraft engineer as far as i remember, he might be ok.

Bruthal

Dont forget who to blame if it blows up:D

M cebee

he's asking the same question in the heating forum

so he may do it another way anyhow:pac:

Bruthal

M cebee wrote: »

he's asking the same question in the heating forum

so he may do it another way anyhow:pac:

At least we wont be blamed then:)

Kashkai

Robbie, that picture you posted up is the existing timer alright. I came across that link yesterday myself but there was no indication as to what terminal was what. I've rechecked the back of the APT timer and there is no labelling of any sort apart from the terminals being listed as "1", "2" and "3".

Sorry I missed out on the exchange of posts between you guys yesterday as my Dad is in hospital and I spent most of the day visiting him. Will give the suggested wiring a go now. Hopefully I'll be able to report back later . Thanks to you both for taking the time to figure this out for me.

Bruthal

Prosperous Dave wrote: »

Robbie, that picture you posted up is the existing timer alright. I came across that link yesterday myself but there was no indication as to what terminal was what. I've rechecked the back of the APT timer and there is no labelling of any sort apart from the terminals being listed as "1", "2" and "3".

Sorry I missed out on the exchange of posts between you guys yesterday as my Dad is in hospital and I spent most of the day visiting him. Will give the suggested wiring a go now. Hopefully I'll be able to report back later . Thanks to you both for taking the time to figure this out for me.

Yes id be confident mcebee is right about his memory of the apt connections, i connected loads of them down the years myself and they are a simple timer, but so is my mind these days:), but it should work according to post 21 but before you remove the apt, you could test the terminals with a phase tester with the power on, brown should be live, and when you manually turn on the timer with the front selector, the black should now become live also, and grey should show nothing, and black should go off with manual switch in off position. That will confirm it for certain.

Hopefully your father is not too bad.

Kashkai

robbie7730 wrote: »

Yes id be confident mcebee is right about his memory of the apt connections, i connected loads of them down the years myself and they are a simple timer, but so is my mind these days:), but it should work according to post 21 but before you remove the apt, you could test the terminals with a phase tester with the power on, brown should be live, and when you manually turn on the timer with the front selector, the black should now become live also, and grey should show nothing, and black should go off with manual switch in off position. That will confirm it for certain.

Hopefully your father is not too bad.

Robbie

I checked the terminals on the APT timer as you stated above and you were correct, i.e. brown was live with grey showing nothing and the black switching on/off depending on whether I flicked the switch or not.

I connected up the new timer as stated above and it works fine.

Many thanks to you and Mcebee

Bruthal

No bother. mcebee is the main man