Ecodan FTC Electrical Wiring

[funkerman]

Hi,

I'm new to this forum and heat pumps and I'm looking for a little bit of advice.

I'm currently in the middle of an Ecodan 8.5KW install, all plumbing and electrical work is complete and the pump is secured. The system is ready to be commissioned but before doing so I began checking over the electrical work, more exactly the wiring inside the Mitsubishi Flow Temperature Control box (FTC2). Inside the FTC2 box is the relay board as well as the main board. I have checked the voltage on the connector that feeds the FTC2 with 240v mains and I am getting a good reading. However if I check the flex which runs from the FTC to the Time Clock I'm not getting any voltage reading. Similarly if I take a reading form the cable to the programmer (PAR-W21AA) or the fuse on the main board I'm not getting any reading.

Obviously I'm now more than a little concerned, I hope that the pump needs to be operating in order to complete the system but I can't see it. Surely I should have voltage running to the time clock regardless of what other components are or aren't connected? I'm now extremely worried, tired and stressed, I really hope I haven't blown anything. I've checked the obvious such as fuses etc.

Any feedback would be appreciated.

Thanks.

Jon.

[Brian_UK]

Hi Jon, firstly I have no knowledge of your system but having had a quick read of an installation manual ---
http://ecodanlive.mitsubishielectric...pan_Manual.pdf
It may be that until the heat pump is powered that the necessary control signals have not been generated.

A lot of remote controllers/indicators are low voltage, fed from the unit, and/or have a serial feed integrated with it.

If you can give details of which terminal numbers you are checking voltages on then it might assist analysis.

Stupid question perhaps, but,,, your time clock isn't battery powered is it?

[frank]

Jon

The timeclock should be powered from terminal 1 of the 10way terminal block where the seperate mains incoming connection is.

The heating demand output from your timeclock (240v) should connect onto terminal 4 and then go to your space thermostat. From the thermostat it should connect to terminal 5 on the FTC terminal TB145. Terminal 2 on TB145 is your live feed to your 2 port heating zone valve.

The hot water output from your timeclock should connect to terminal 6 on the 10way block, and from here it should go to your cylinder stat. The output from your cylinder stat should energise the DHW 2 port valve.

The pump is energised via the auxillary contacts of the 2 port valves.

It is recommended by Mitsi that 2 pumps are employed - 1 on the heating flow and 1 on the return.

The interconnecting S1,S2 S3 cable should have a triple pole isolating switch installed.

[corradokid82]

HI,

I have just fitted one of these new FTC2 units and have exactly the same problem. Power to the bottom board on the terminals but it does not go any where from there. As the FTC2 is all pre-wired the lower board acts as the 10 way box. I have another one to start monday next door so on friday I swapped the bottom boards over but still no joy. If you put the live directly into the top board the system half comes to life but as that bottom board feeds all the other functions it proves again that this lower board is at fault.
It is not possible to wire out the lower board due to a slight alteration to the connectors on components.
I will be contacting mitsubishi on monday to request a site visit. If you have had any luck please let me know.

[corradokid82]

Hi, you are correct on the wiring explanation but this is for the normal FTC unit. Mitsi have just released a version 2 which is for a pre plumbed kingspan pack. There is an extra board in this one so all that is needed is a 240v feed and a 2 core signal cable. All the other wiring is pre made. Very good idea(if it worked)

[Oakgreen16v]

Hi - did you get anywhere with the site visit? I have fitted quite a few of these FTC2 systems without any problems, was it a Kingspan pre plumbed FTC2 system or a standalone one you fitted?

[funkerman]

Hi,

Thanks for all of the rpelies and apologies for the delay in replying.

The unit I have is the FTC version 2, which as correctly stated above has the wiring centre on the lower board.

I found the answer to the problem though, you must have the temperature cut off (?) which wires to the cylcinder thermostat wired. Without it the other components are not provided with any voltage. I am guessing that this is some kind of protective messure. In my instance I had the wrong terminal block wired up (my thermostate has two terminals). With it switched over the LED's start flashing and the time clock illuminates so it looks like no damage has been done.

The system is due to be commissioned tomorrow - I will let you know the outcome then.

Regards,

Jon.

[corradokid82]

Hi, it was like you just said, the overheat safety cut out had tripped. Looks like they are factory set and tested and not reset on certain occasions. Interestingly though both were set with the cut out temp too low. So when they heated up even with the ecodan only it re-tripped. They are adjustable which i didnt think you could have with an unvented system, so I adjusted it so it no longer tripped. Another thing to check is the immersion bosses, they are not always tight and pop the rubber when they warm up. I had an interesting chat with the engineer that came out to us today to help. He said we were also missing a manual specific to the FTC2 which he assumes is not being replaced by kingspan when they put the units together. I have had a look at one of his manuals and it contains alot of useful info so i will be onto mitsi for this.

[Oakgreen16v]

glad to hear the problems are now sorted, sounds like the high limit stat is the cause for both of you, when it is satisfied it cuts all power to components on the relay board in order to ensure the system shuts down.

[mickyspark]

Hi Funkerman
the FTC2 panel needs a dip switch changing in out door unit (SW1-3 check manuel though, going off memory) and its own power feed, your not getting power to top panel because you need a link via a high temp stat on the connector block bootom right on ftc2 panel, I think its marked up S1, S2, earth (not to be confused with s1 s2 s3 communicating cable which on the FTC2 needs its own supply and s1 not connecting, hope this helps
Regards
Mickyspark