evohome ATF600 wall mount cable

[prozak1982]

Has anyone extended the supplied low voltage cable without using a connector if so how? I need it at least double in length and have a single run/no join but finding the pcb connector on its own for one end of the cable has proved unsuccessful let alone finding a longer cable with that same connector already on it!

[DBMandrake]

Surely it's easier to just buy a longer piece of cable instead of joining it ?? It's just figure of 8 cable with screw terminals to go into at both ends...nothing fancy needed.

On my install the ATF600 is mounted on a wall without a back box where the thermostat used to be so no room for the transformer so I decided to mount the 5v transformer in the wiring centre in my boiler closet, and use the original two wire thermostat cable that runs through the plaster and under the floor for the 5v supply. Works fine even though the wire gauge and length is near the limits recommended by Honeywell. (For voltage drop etc)

[prozak1982]

How did you connect your original two wire thermostat cable to the 5v transformer without using a terminal strip/block to join onto its black and red low voltage cable?

[DBMandrake]

How did you connect your original two wire thermostat cable to the 5v transformer without using a terminal strip/block to join onto its black and red low voltage cable?

Ah, sorry you're right - I forgot there was a permanent pigtail coming out of the transformer.

Mine is mounted inside a spare corner of the wiring centre box well away from any high voltage connections and uses two spare terminal block terminals provided in the wiring centre to join to the cable that runs under the floor.

In your situation I'd either use a miniature terminal block, or if you want a join that is free of any terminal blocks and tidy use an end to end overlapped soldered joint with heatshrink for insulation - this will provide a strong and very tidy result.

[prozak1982]

Good shout thanks although I was just contemplating using the power supply (plug) that came with the ATF800 desktop stand but I’m left scratching my head even more so now as it’s 5v as opposed to 4v on the ATF600!

[DBMandrake]

I think the power supply provided with the ATF 600 is just poor - mine measures about 4.6 volts vs the 5.0 volts from the desk stand power adaptor, and when you couple that with voltage drop from a long run of cable it could potentially cause problems. (Although it doesn't seem to for my installation) The specs say it should be 5 volts.

If it's more convenient I can't see why you couldn't use the desk mount wall wort power supply instead - just solder a DC barrel connector (socket) on the end of your cable and plug it into the desk adaptor. I probably would have done that if there was a 3 pin socket in my boiler closet however as there wasn't it was easier to put the ATF 600 power supply inside the wiring centre as both the cable run to the wall mount and 240V AC were available within the enclosure and I had lots of spare terminals.

[prozak1982]

I snipped the end/connector off the power supply (plug) supplied with the ATF800 desktop stand and connected the + & - wire directly to the ATF600 wall mount but it error messaged (see below) I’m no electrician however I don’t mind giving it a go and that I thought would have worked wonders especially like you said being 5v so I’m once again scratching my head

[prozak1982]

FAULT

MAINS WIRING

Please check system or contact installer

[DorrisMancer]

It would be far preferable to sink a back-box to house the power supply and to use the old thermostat wiring to provide a mains supply from the wiring centre.

[DBMandrake]

FAULT

MAINS WIRING

Please check system or contact installer

Check the polarity is correct, also from memory there are three terminals on the mount but only two should be used so make sure you're using the correct ones. I can't see any reason why the 5v wall wort shouldn't work just as well if not better than the one supplied with the wall mount.