A/C installation "outdoor to indoor" cable query

[Zdb]

Agreed, however I see it being used all the time on A/C installs for the interconnection between the outdoor/indoor unit.

I'm guessing the cable needs mechanical protection because it passes through a wall and they don't want to use an RCD for obvious reasons. Also you can't really use SWA as going by what I saw yesterday there's nowhere to terminate a gland.

Both the indoor and outdoor units had a cable grip so nowhere to put compression / SWA glands.

 

[Zdb]

Also from what I saw they don't even attempt to earth the braiding they just cut it off.


Anyone come across this when looking at A/C installs?

 

[Strima]

Do they need mechanical protection? Most A/C units I've seen are close to the wall so very little risk of impact damage.

Also the braid should be earthed at the supply end.

I'd be leaning towards using H07 cable for this type of application.

 

[Pete999]

Do they need mechanical protection? Most A/C units I've seen are close to the wall so very little risk of impact damage.

Also the braid should be earthed at the supply end.

I'd be leaning towards using H07 cable for this type of application.

I think what people need to realise is HVAC Mechs are a trade in their own right, and rightly so, whilst they are aware of the dangers of refrigeration gases, and the correct handling of a dangerous item, they tend to stick to their trade, and go with the flow regarding the electrical side of their industry.
Until the manufacturers of split A/C systems, align themselves withe vagaries of BS 7671 we will always get these anomalies, as to what is the correct type of wiring needed to interlink the inner and outer parts of the system, remember most of the "Split systems" come with the interlink cabling included in the package, so with some experience in this area I would suggest that the IET and A/C manufacturers get together and iron out the correct way to install these systems, until they do we will always have this problem, blime a long post there Pete, take another sip.

 

[Ian1981]

Only use of earthing the braid is for it to act as screening as far as I’m concerned as it’s no good for taking fault current and is unsuitable to be used as a cpc in its own right.
It offers very little mechanical protection to the cable.

 

[multimick]

Only use of earthing the braid is for it to act as screening as far as I’m concerned as it’s no good for taking fault current and is unsuitable to be used as a cpc in its own right.
It offers very little mechanical protection to the cable.

seen a couple of hot tubs recently which specified sy cable from commando plug to hot tub

 

[Leesparkykent]

Never seen AC units where the indoor cassette is powered from the condenser. Usually just a control cable for signalling with the cassette on a fused spur and condenser on its own supply.

 

[Pete999]

Never seen AC units where the indoor cassette is powered from the condenser. Usually just a control cable for signalling with the cassette on a fused spur and condenser on its own supply.

Just another way of doing it Lee, problem being AC/HV blokes don't always look at it that way, try and keep it all under one roof, so to speak, but yes seen it that way many times.

 

[Leesparkykent]

Just another way of doing it Lee, problem being AC/HV blokes don't always look at it that way, try and keep it all under one roof, so to speak, but yes seen it that way many times.

Yes mate we have recently started taking on the mechanical side of things so it's all under one roof.

 

[Pete999]

Yes mate we have recently started taking on the mechanical side of things so it's all under one roof.

Got your Gas safe handling qualification then?

 

[Leesparkykent]

Got your Gas safe handling qualification then?

No I'm doing my gas safe ATM but we Have gas safe plumber and F-gas aircon guy cards in.

 

[Zdb]

I did my F-gas but steer clear of A/C work tbh. Best to stick to your own trade.

So out of interest what type of cable do people recommend for this interconnection? Would need to be a multicore flex suitable for outdoor use.

 

[Zdb]

NYY-J / H07RN-F?

 

[Zdb]

So what is the best type of able to use for the interconnection?

I keep seeing AC engineers using SY outside and I'd like to offer them a better alternative.

 

[Zdb]

Keep seeing the same old SY cable that looks pretty prerished

 

[Amp David]

All they do is act as a comunication wire telling the condenser to kick in i thought. Howcan it become overloaded?

 

[Pete999]

All they do is act as a comunication wire telling the condenser to kick in i thought. Howcan it become overloaded?

And a supply to the Evaporator Fan.

 

[mydigitalhome]

Interesting, so a SY is a deviation of the regs as main supply cable for fixed wiring which should have been identified on the electrical certificate too. Covered in the cinema today.

 

[Pete999]

Interesting, so a SY is a deviation of the regs as main supply cable for fixed wiring which should have been identified on the electrical certificate too. Covered in the cinema today.

"A departure" to be exact

 

[Zdb]

We shouldn't be putting any departures down really. No more SY cables for AC interconnection then?