ATC 800+ Wiring

[Chunk1234]

Having a few problems with wiring an ATC800+.

I've followed the Forttex diagram here and ended up with a setup as shown in the picutre at the bottom of this post. The problem I've got is that no power seems to be getting to either the heating or cooling relay. The unit functions correctly, even switching between heating and cooling as it should - it's just that whatever I've plugged into the heating and cooling relays just never seem to recieve power. Any suggestions?

In detail:

1. Cooling live goes to terminal 1

• Terminal 2 is connected to terminal 4 using live wire

• Heating live goes to terminal 3

• Terminal 4 is connected to terminal 7 using live wire

• Terminal 5 and 6 is used for probe

• Terminal 7 is connected to mains live

• Neutral from cooling, heating and mains go to terminal 8

• Earth from mains, cooling and heating go to a terminal block (note picture shows them going to different terminals but they are now wired to go to a single terminal)

[borischarlton]

Morning,

I had exactly the same problem, you need to google ATC800=+ wiring instructions. You need to have a live supply to both the heating and cooling and that is why you have no power. There are really good instructions on an aquarium forum,I just don't have the time to search now.

Rob

[Chunk1234]

Hi, thanks for the response. I've done quite a bit of googling in order to get this far. I read that you need to provide live to both the heating and cooling realys, but my understanding was that you do this by looping from terminal 7 to 4 and then from 4 to 2. I've done this, but still no power. Am I not understanding the instructions correctly?

[richc]

Wiring sounds about right, have you got a voltmeter or something so you can check the connections across the relays are working?

[boingy]

Have you connected the neutrals to the heating/cooling devices?

And you must make sure all the earths are tied together. Not connecting the earths will not prevent it from working but will mean it is less safe.

[Chunk1234]

Sadly, I don't have a voltmeter or any means by which I can test each connection.

All of the earths are connected together. The picture is an old one before I realised my mistake - they now all go into a single terminal.

Heating and cooling relays both connect to a trailing plug socket. The neutrals are connected to the sockets and then all into terminal 8 on the temperature control unit.

At least Im not the only one stumped by this not working.

[richc]

Two ideas...

Can you scrounge together a 9v battery and a torch bulb? If so make a simple circuit with these across one of the relays (after disconnecting the current wiring to the relay) and test whether it is making a connection.

Or, wire a short across one of the relays, this should make that output constantly live, this will check the rest of your wiring.

[Chunk1234]

How would you go about making a short? Bit out of my depth here. Does this all suggest that somehting could be wrong with the unit itself?

[borischarlton]

Where are you Chunk??

[Chunk1234]

Im in London. Would it be an option to use an electircal testing screwdriver to diagnose the fault by trial and error? Touch it to each point along the live cables to see where the fault lies?

[richc]

How would you go about making a short? Bit out of my depth here. Does this all suggest that somehting could be wrong with the unit itself?

I'd just add a loop of wire across the two terminals, eg. 1-2. This would act as if the switch inside the box was closed.

Your wiring looks very similar to the identical box I wired up a couple of weeks ago so I am suspicious of the box itself.

The idea of getting a voltage check screwdriver is not a bad one, they are cheap and would let you know what was connected.

[Kev888]

+1 for the voltage check screwdriver - they're properly insulated down to the tip and its harder to blow stuff (including yourself) up by accident than fiddling around with batteries and bulbs on a mains appliance.

It can confirm if you have live to pins 2 & 4, and if you have live to pins 1 and 3 'when' the appropriate relay acts but not before - that will tell you conclusively if the relays are switching properly or not. If they are, you can also test the lives on your sockets to make sure it is filtering through to there correctly

If that is working but you get no response in whatever you've plugged in then I'd suspect (as boingy says) a problem with the neutral, or maybe a general problem with the socket wiring. And of course check the appliance you're plugging in on a normal socket to make sure its not a dudd.

But PLEASE take care and don't do any of this if you're 'at all' unsure about safety - there's something wrong and until you know what don't assume that (for instance) a neutral or earth wire won't accidentally be live.

Cheers
Kev

[Chunk1234]

Thanks for all the help. I've tested each plug socket (cooling and heating) and both live terminals seem to be recieving power no matter what the light on the temp controller shows. If I've carried out the wiring correctly (which it looks like I have) ... I dont understand why this would be the case. :S

[Kev888]

Hi, I think I may be misunderstanding - that seems to be the other way around to what it was doing in the first post when whatever you plugged in 'never' got power?

It sounds like something is very wrong anyway - I can't see any problem with your wiring description so it seems most likely that either the ATC is faulty or theres something wrong with the peripheral wiring. It may be worth disconnecting the 'out' leads from pins 1 & 3 when you test with the voltage test screwdriver, to try the unit in isolation from other possible causes (I'd suggest making the loose ends safe in a connector block just to avoid mishaps)..

(But as before only tinker if you're confident to do so).

Cheers
Kev

[JontyR]

Chunk,

it's not the time delay is it? When I got a TC10 I wasn't aware that there's a time delay setting to prevent the cooling circuit coming on too quickly (to save frying fridge compressers I think). Anyway, I thought mine was faulty when I was testing it until I changed the time delay setting to a shorter time lapse.

Might be worth a try.....