More Renewable Shenanigans at Nowty Towers

[Tinbum]

I'm really impressed with the one I have installed but we have had a run of miserable days PV wise so had to turn it off for the moment.

[AGT]

Hi Nowty,

I’m slowly talking SWMBO into the A/C route, can I ask on the Panasonic unit do you wire the mains to the external AC isolator and then a mains/comms cable with the pipework back to the internal unit.
Cheers!

[nowty]

Hi Nowty,

I’m slowly talking SWMBO into the A/C route, can I ask on the Panasonic unit do you wire the mains to the external AC isolator and then a mains/comms cable with the pipework back to the internal unit.
Cheers!

My unit has an alleged Panasonic compressor, but it is certainly NOT a Panasonic unit. On mine, the mains supply HAS to be supplied to the indoor unit first, then there is a mains interconnector to supply the power through the cable / pipe bundle to the outdoor unit.

There is an internal relay isolator in the indoor unit so if you try and connect the mains power to the outdoor unit and expect the power to flow up the interconnector cable to the indoor unit it won't.

But read the manual because other models may be different.

[Oldgreybeard]

My unit has an alleged Panasonic compressor, but it is certainly NOT a Panasonic unit. On mine, the mains supply HAS to be supplied to the indoor unit first, then there is a mains interconnector to supply the power through the cable / pipe bundle to the outdoor unit.

There is a relay isolator in the indoor unit so if you try and connect the mains power to the outdoor unit and expect the power to flow up the interconnector cable to the indoor unit it won't.

But read the manual because other models may be different.

Exactly the same for ours. The indoor unit has a normal three core mains cable, then there's a four core power and control cable from there out to the outdoor unit.

[Fintray]

Hi Nowty,

I’m slowly talking SWMBO into the A/C route, can I ask on the Panasonic unit do you wire the mains to the external AC isolator and then a mains/comms cable with the pipework back to the internal unit.
Cheers!

My unit has an alleged Panasonic compressor, but it is certainly NOT a Panasonic unit. On mine, the mains supply HAS to be supplied to the indoor unit first, then there is a mains interconnector to supply the power through the cable / pipe bundle to the outdoor unit.

There is a relay isolator in the indoor unit so if you try and connect the mains power to the outdoor unit and expect the power to flow up the interconnector cable to the indoor unit it won't.

But read the manual because other models may be different.

I think I bought the same unit as Nowty (except it is white) but mine has the mains to the outdoor unit.

[Stinsy]

Hi Nowty,

I’m slowly talking SWMBO into the A/C route, can I ask on the Panasonic unit do you wire the mains to the external AC isolator and then a mains/comms cable with the pipework back to the internal unit.
Cheers!

The European way is to have the mains wired to the indoor unit (followed by a mains/signal 4-core to the outdoor), the American way is to have the mains wired to the outdoor unit (followed by a mains/signal 4-core to the indoor). My unit came pre-wired ready for European-style installation but you can wire it the other way around if you like.

You have to provide means of isolation for anyone servicing the outdoor unit. In a commercial/industrial setting this will be a rotary isolator next to the outdoor unit. However in a domestic dwelling it is also reasonable to isolate at the CU or next to the indoor unit. There is no need to send power back and forth, even if you supply power to the indoor unit first and put a rotary isolator next to the outdoor unit you’re isolating LN and Signal to the outdoor unit.

[Oldgreybeard]

I just fitted a 13A fused DP switch next to the indoor unit, spurred off the ring (happened to be a double gang socket right below where I fitted the indoor unit). Makes it easy to isolate the power to work on it, could even pull the fuse out as an extra safety measure. These things need a fused supply anyway, so this seemed the easiest way to do it.

[nowty]

The European way is to have the mains wired to the indoor unit (followed by a mains/signal 4-core to the outdoor), the American way is to have the mains wired to the outdoor unit (followed by a mains/signal 4-core to the indoor). My unit came pre-wired ready for European-style installation but you can wire it the other way around if you like.

Careful with that as that's what I tried with my second install as the power was nearer the outdoor unit, but the indoor unit would not power up as there is an isolation relay inside the indoor unit. I had to extend pre wired mains lead from the indoor unit down to an area close to the outdoor unit where the power was. So the power ran up the extended mains cable up to the indoor unit, then the power flowed through the 4 core cable back down to the outdoor unit.

EDIT - I guess you could parallel up the mains cables in the indoor unit, but that would defeat the purpose of the isolation relay inside the indoor unit.

[Stinsy]

I just fitted a 13A fused DP switch next to the indoor unit, spurred off the ring (happened to be a double gang socket right below where I fitted the indoor unit). Makes it easy to isolate the power to work on it, could even pull the fuse out as an extra safety measure. These things need a fused supply anyway, so this seemed the easiest way to do it.

And that is perfectly acceptable in a domestic setting. Imagine a shop/office/factory, the guy working on the outside unit needs to be able to isolate it within eyesight so that he can be confident no one will re-energise it without his knowledge.

If someone wants to fit a rotary isolator next to the external unit at their house, they can. But it isn't "required".

[Oldgreybeard]

I just fitted a 13A fused DP switch next to the indoor unit, spurred off the ring (happened to be a double gang socket right below where I fitted the indoor unit). Makes it easy to isolate the power to work on it, could even pull the fuse out as an extra safety measure. These things need a fused supply anyway, so this seemed the easiest way to do it.

And that is perfectly acceptable in a domestic setting. Imagine a shop/office/factory, the guy working on the outside unit needs to be able to isolate it within eyesight so that he can be confident no one will re-energise it without his knowledge.

If someone wants to fit a rotary isolator next to the external unit at their house, they can. But it isn't "required".

I've locked off supplies many times over the years. Almost all of those lock offs will have been with a bog standard lockable clamp, with a small padlock fitted to it and a warning tag with my name on it. I can count on one hand the number of times I've locked off a rotary isolator, TBH. I've also locked off standard 13A switch fuses a few times, just pull the fuse and stick a cable tie and warning flag through the empty fuse holder. My bag of goodies includes half a dozen standard lock-off clamps that will fit any circuit breaker or RCD etc with a manual operation lever. I would be very surprised if any electrician didn't also have lock-off clamps and understand how to use them for safe isolation, TBH. There has never, ever, been any requirement in the regs for an isolator to be within eyesight at the point of work.