contactor for underfloor heating

[bennjy]

Hi
I've installed the electrics for an underfloor heating system. The system has 6 manifolds each with a small pump. There is then a primary pump that pushes hot water through the system from an aerobic digester next door. I have fitted 6 contactor each using a switch wire from the thermostat to energise terminal 1 of the contactor, I have then linked from terminal one to a of the coil. I've taken a neutral to all contactor in parrelal in terminal 2 then from 2 to a2 of each contactor. I've then connected in parrelal the primary pump to terminals 3 and 4. This works fine with one stat, when it calls for heat aswell as energising the secondary manifold pump it also energises the contactor and energises the primary pump. The problem is, is that when another stat calls for heat if the other stat goes off the contactor still stays energised until all stats are off. I don't think it's latching contactor I'm sure there non latching could be wrong tho. I'm sure it's a wiring fault so any help would be great .

 

[Darkwood]

Can you show us a sketch wiring diagram please as it will be a lot simpler to see what you have done than to try imagine it from a long post of info'.

 

[bennjy]

Yeah I'll draw then take photo

 

[bennjy]

How do you add a photo

 

[Leesparkykent]

You will probably need relays. A sketch of what you have done will be good to see though. This diagram may help if you have a similar setup.

 

[Darkwood]

How do you add a photo

When you start a post the option bar over your post has a symbol with a pic of a tree, click it then click choose file, find your pic and double click it to bring it in the box than click upload pic .. you may have to wait a few minutes for it to load.

 

[bennjy]

https://www.google.co.uk/search?ie=...pic%2F5616-how-to-wire-a-contactor%2F;319;203

That's pretty much it. The light is a pump tho. Has 6 wired in parrelal. No switch just a link from 1 to a1.
I did a sketch but not sure how to upload pic

 

[bennjy]

Asking for a url

 

[bennjy]

There so contactors. Seems like a back feed so would a relay over that issue?

 

[bennjy]

Sp contactors

 

[Darkwood]

Asking for a url

Just above that click the option 'from computer' then click choose file.

 

[dansk]

OP - Can you tell me how many thermostats you have 6? - this is easy to wire - A1 to neutral, A2 switch live from the thermostat, put a permanent live into the contactor, load side of the contactor to boiler enable. The little pumps need to be connected to A2. The primary pump to boiler enable.

 

[bennjy]

Hi yes there are 6 stats. I've miss understood the diagram then I'd say. You say a2 switched live then a2 neutral? Would it be possible to do a little scetch sorry to be a pain

 

[dansk]

What brand contactor have you used?

 

[bennjy]

Imo. Cr40c heating contactor 230v 2 pole.
Usually use hager for doing lighting but these were all I could get at the time.

 

[Leesparkykent]

I misunderstood in my post #5 I skim read the bit about 6 contactors, I thought you only had 1. Draw it out, it's not a difficult one.

 

[dansk]

OK - repeat this at each manifold.

From a local switch fused spur bring Live & Neutral into a JB (small adaptable box), connect live into "2" connect the primery pump/boiler enable to "1"

Connect A1 to Neutral.

The switch live from the thermostat connect to A2 and also connect the live for the local pump to A2.

Make sure all the electrical feeds to the manifolds are fed from the same heating circuit.

 

[bennjy]

Thanks for that. The way I've done it is to energise the coil with the switched feed then terminal 2 to primary pump but I guess that is enabling the contactors to stay latched once switched until all feeds are broken. I've mounted the time clock on a adaptable box so all cabling and contactors are in there. I've used 5 core tho so it's easy enough to do there

 

[Leesparkykent]

Thanks for that. The way I've done it is to energise the coil with the switched feed then terminal 2 to primary pump but I guess that is enabling the contactors to stay latched once switched until all feeds are broken. I've mounted the time clock on a adaptable box so all cabling and contactors are in there. I've used 5 core tho so it's easy enough to do there

Are there any valves?

 

[bennjy]

No valves