air source heat pump wiring

[Dazz0i]

Hey guys.

Anyone had any previous experience with a mitsubishi ecodan?

Basically, we have all the details off the plumber, and have also called their pre-sales tech' line and still not got any solid answers.

The unit it self has a running current of 10.3A, and specs for a 25A earth leakage breaker (RCBO i assume from that?) It apparently has a 5A start up current.

Basically, the main question being anyone know if they're a type C or D? No one seems to be able to give us a definate answer, and obviously the different requirements to get a decent EFLI level is a different cable, breaker dependant....

Any help//info greatly appreciated!

 

[Taylortwocities]

Sure, which Ecodan model is it? Edit: sounds like the 8.5KW unit.

The manual specifies the feed for each model.
I recently installed a 14KW Ecodan which needed a 40A feed. This was run off a B40 MCB with no problems.

You'll also need an immersion feed - this will go through their fancy immersion controller. The FTC runs the immersion on a timed basis to make sure the tank gets up to a high temperature - to kill off Legonaire's Disease bacterea etc.

I found that Mitsubishi are only really happy dealing with their authorised installers

Have fun, some of the wiring is a challenge. The last one I did had solar panels and a underfloor heating controls for 12 zones.

 

[Dazz0i]

Yea they do 3 models in the ecodan range, this is the middle size one.

This setup is underfloor heated on RF controls and a 3kw tank. But no roof pannels.

Real blunder now is that the cable route now between pump and tank has been plastered due to the plumber changing his spec so late into the job. So looking like external routing on walls.

The plumber is an installer for them i believe.... so he can keep his name to that. Manages to get all the government grants back etc.

So, guess we'll spec a cable for a C type (plumbers original instruction) and go from there. SWA, so don't wanna be having to dig it back up.

Looks like it'll have to be a 32amp MCB as 25 is a really odd requirement.

 

[Taylortwocities]

Looks like it'll have to be a 32amp MCB as 25 is a really odd requirement.

Sure, some (not many) CU manufacturers make a 25A mcb but the CPD is there to protect the cable so 32A is OK provided you have at least 4mm² cables feeding the Ecodan.

 

[Dazz0i]

Well, because the plumber is convinced it should be on a C type (he's the one involved in certification of the pump, so not too fussed about arguing.) and the cable cost isn't our concern, it'll be a plenty big enough to get the EFLI low enough.

cheers guys much appreciated. Info provided that mitsu' failed to provide themselves.

 

[Taylortwocities]

I still do not know why you think that a C type is required.

 

[Dazz0i]

I don't, your word is good enough for me. But, the plumber seems to believe it's a C (cause ones he used to fit required a D and doesn't believe that it could be a B), and i just can't be bothered with the arguements and contra-charges if he want's the cable to be different.


Like i say, not being the one costing the cable, so if he wants to pay the extra for a bigger cable, that's his business.

 

[Taylortwocities]

But he's a PLUMBER, not an electrician. Ah well. as you say, why not - if it meets the EFLI requirements.

I hope you'll be advising him on the size of pipework that he needs to install.