Earthing air conditioning equipment

[r.bartlett]

Had a call last week where the install crew had mis-wired the unit. The mains should go to the indoor but it had been wired to the outdoor.(long story no longer works for us......)

Now we rewired the supply using a new cable to the inside but that left the interconnect one cable short-IE no earth.

As I understand it the copper piping is considered sufficiently earthed (no one ever bonds the a/c pipes AFAIK)

We had considered linking a 6mm G/.Y up to the unit next to the outdoor but thought if that was ever removed the earth would go with it.

Ended up leaving the old SWA in place right back to the consumer unit and just using one core as a separate earth.

So my question is could we have left the outdoor as it was without this earth and argued that the copper piping provides suitable earthing?

Cheers

Richard

 

[Lectrician]

No. I very much doubt it is double insulated.

What cable is used as interconnect? Surely it has earth?

all the A/C units I have wired have the mains taken to the outside panel, and then an interlink cable between the two.

 

[r.bartlett]

No. I very much doubt it is double insulated.

Please explain that a bit further..from my perspective a 5/8 and a 3/8 copper tube provides a better earth connection than a bit of 1.5mm wire..

What cable is used as interconnect? Surely it has earth?

We use that envirotuff usually 3 + E however this unit needs 4+ E so E was used as one of the control hence the lack of an earth wire..

all the A/C units I have wired have the mains taken to the outside panel, and then an interlink cable between the two.

Sadly thats why some get caught out. Certain manufacturers still 'do' power to indoor on the odd system. It's bleedin obvious as they supply the indoor with a tail lead but this guy wasn't the brightest

 

[Lectrician]

Earth conductors must not be used for any other purpose, even if sleeved.

A pipe or structural steel may be used as 'a bonding conductor' but not as a circuit protective conductor.