Wiring for AC unit

[indus]

Hi

I want two AC units in my house, so called 'easy install units' ie condenser on the outside and wall mounted unit inside.

In terms of the power supply is it correct I need three core 20a supply straight from the consumer unit?

Does it need to be armored?

On a slightly different note; the quotes I've had to install seem pretty high ie between £1k and £1,5k labour charge per unit. The house is in bits at the moment so running cables/pipes is very easy.

Is there any reason why a competent sparky couldn't run the wires and a plumber run the copper pipes?

From what I can gather apart from he wiring as discussed above all that is needed is a four core cable back to the internal unit and two copper pipes.

Many thanks

 

[swampy2]

You can buy self install split units, sparky would wire up for supply & you could install them . The refrigerant is an issue for anyone outside that field, self install units has the refrigerant fully contained within detachable flexible pipes/couplings.

 

[ekmdgrf]

It needs whatever power the manufacturer says it needs. Hand the glossy broacher to your spark and say: "please could I have a quote to run power to this."

I'm not sure what the plumber would say, give them a call and see. As previously stated, you may have a problem gassing the unit. I wouldn't know how easy that is but it never ceases to amaze me what BOC are willing to sell me.

 

[indus]

It needs whatever power the manufacturer says it needs. Hand the glossy broacher to your spark and say: "please could I have a quote to run power to this."

I'm not sure what the plumber would say, give them a call and see. As previously stated, you may have a problem gassing the unit. I wouldn't know how easy that is but it never ceases to amaze me what BOC are willing to sell me.

As an easy install split unit with short runs I would have assumed it was of the 'ready gassed' variety?

 

[ekmdgrf]

If it's sold as a DIY install unit, then yes, almost certainly. Might be wise to double-check, rather than assume though. Could be a rather painful oversight

 

[SimonH2]

Gassing a system isn't something I'd entrust to a plumber unless he'd demonstrated that he was far more than what most of us would understand from the term. Very, very few would have either the gear or the knowledge of how to use it.
Unless the system comes with all pipework pre-connected - so assuming flexible pipework with quick-connect plug in connections - then coming pre-gassed (as most small-medium commercial ones do anyway) doesn't mean you can dispense with the services of a refrigeration engineer to commission the system.

You need a high vacuum pump, together with a gauge set, and know how to use it. The vacuum is used to test for leaks, but more importantly, it removes air and water from the system and pipework. Only at this point can you open the taps and release the refrigerant that will have been pre-installed in the condenser.
There is a cheat - it involves pressurising the system with refrigerant and then letting it out. As the pressure is let out it'll take most of the air and most of the water vapour with it - repeating will progressively reduce the amount of both. But letting out refrigerant is illegal - you're supposed to pump (there's that pump again) it into a recovery cylinder and pay to dispose of it.

As to lectrics, as already stated - you need what the unit needs !
Some need a supply to both units. Some only need a supply to one unit and the other is fed from that - and the supply could go to the indoor our outdoor unit (more usually the outdoor unit as that is the power hungry one). The type of cable used depends on how and where it's to be installed, and don't forget the right means of isolation.

 

[mdbalson]

Refrigeration pipework is different pipe to normal plumbing pipe, it has a thicker pipewall due to higher pressures being used in the system.

You have to have done a F-Gas course to handle Refrigerants, which most plumbers will not have.

The pipework has to be pressure tested with OFN to check there are no leaks in the pipework, the pipework then has to be evacuated with a vac pump to remove all air and water from the system.
Then the refrigerant can released from the condenser into the system, also it may require additional refrigerant is added to the system if the piperun is longer then what the condenser is base charged is for.

It requires specialist tools to install and commission an Air Conditioning System.

 

[Steve]

Don't forget the refrigeration pipework isn't soldered, it's brazed (I think).

 

[indus]

Many thanks.

I have now found a full time ac installer who will charge a more reasonable fee for fitting and so will be getting him to do the job.

Thanks to all for the advice

 

[ricicle]

Don't forget the refrigeration pipework isn't soldered, it's brazed (I think).

Correct

 

[winston1]

Hi

I want two AC units in my house, so called 'easy install units' ie condenser on the outside and wall mounted unit inside.

Why? With our so called summers you would never use them.

 

[RF Lighting]

I've got one. Whilst it only got used for about 4 weeks this year, it was absoloutely worth every penny.

 

[Steve]

I got one of the first versions of the b&q air force easy install air conditioners about 6 years ago. build quality not great and it discharged itself of gas over just 2 years. This is why fridge pipework is usually brazed. Having a mechanical connection means it will need servicing within 3 years. like the air con in your car.

By comparison the air conditioners we have in my shop were fitted about 6 years ago and have never been re gassed. And they operate at least 6 hours a day to heat and cool the shop.

Also you will probably struggle to get a reputable engineer to service the easy fit units because they Cannot offer any kind of warranty on their work.

 

[SimonH2]

Why? With our so called summers you would never use them.

You'd be surprised.

Some years ago, I had the option of buying (cheap) a full air-con system for my Discovery - the guy selling it had taken it off as he was trying to reduce weight to use his for trialing. One person in particular couldn't get past the "what's the point with our weather" dismissal - but I didn't care, it worked nicely for me.
Then a couple of years later this person bought a new car - and it came with AC. He never stopped saying how wonderful it was, even in moderate weather. And he also couldn't remember having said how useless AC is in a car in our weather

This is why fridge pipework is usually brazed. Having a mechanical connection means it will need servicing within 3 years. like the air con in your car.

The car is a bit different as it has a rotating shaft seal on the compressor. They also have a condenser fitted in about the most vulnerable position possible !

There's no reason mechanical joints can't be leak free is made properly. Even with all the brazed pipework, the final connections to the units are usually flared mechanical joints.

 

[bernardgreen]

Don't forget the refrigeration pipework isn't soldered, it's brazed (I think).

And it isn't the same as common copper water either.