Air Condition Unit

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seajayess

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Does anybody bond the pipes from air conditioning units. Supplying a 16 Amp conection for an air conditioning unit, and the air conditioning engineer recons it doesn't require a bond, it uses the CPC to bond . The 7671 recons it does, have pulled in a 10mm bond just to be on the safe side thanks CJS

 
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If the pipes are liable to introduce an earth potential, then bond them.

If the outside unit is bolted to a wall or up on a roof its unlikly to introduce an earth potential. If its hidden in the garden behind a bush, or the pipes are buried running to a remote unit then it is likely. Do you realise the 'stone' slabs the units are bolted to when sitting on the ground are actually fibreglass.

 

sparkyrj

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As the pipes between the indoor and outdoor units are connected to the units with no breaks in the copper and the units are earthed via the supply cables there should be no need for bonding.I have worke on quite a lot of aircon supplies in offices over the years and have never seen these pipes bonded.

 

ElectekAir

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Just done my 17th and i brought up this ' air con is in the regs and yes you do need to bond them'

 
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As the pipes between the indoor and outdoor units are connected to the units with no breaks in the copper and the units are earthed via the supply cables there should be no need for bonding.I have worke on quite a lot of aircon supplies in offices over the years and have never seen these pipes bonded.
Just because you haven't seen it done, doesn't mean its correct not to. They are just as important as the water and gas to bond if they are likly to introduce an earth potential.

From your statement above you have missed the main point about bonding. Its because the pipes are earthed via the air con supply cable and are unbroken that you should bond them. Can the supply cable earth (2.5 ?) carry the full fault current of the whole building ?

 

sparkyrj

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usually in the large offices that i work in the aircon systems have outdoor units that are either bolted to walls or standing on plastic feet, and the pipework is run in risers and false ceilings, and covered with insulation that is slid over the pipe (surrounding it completely)as it is put together and brazed, and would not be affected by fault currents from the buildings other supplies and are mostly out of normal reach. It would not be practical to bond these back to the met each time as some are on the roof, some the ground, and in different sides of the buildings, as they are generally afterthoughts and not installed when the buildings were new.They are not the same as incoming services such as gas and water that are run in the ground.

 

seajayess

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Thanks for the replies as I said have bonded them as it says to in the regs, just wondered if anybody else did CJS

 
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usually in the large offices that i work in the aircon systems have outdoor units that are either bolted to walls or standing on plastic feet, and the pipework is run in risers and false ceilings, and covered with insulation that is slid over the pipe (surrounding it completely)as it is put together and brazed, and would not be affected by fault currents from the buildings other supplies and are mostly out of normal reach.Then that is ok not to bond as i interpret the regs

It would not be practical to bond these back to the met each time as some are on the roof, some the ground, and in different sides of the buildings, as they are generally afterthoughts and not installed when the buildings were new.They are not the same as incoming services such as gas and water that are run in the ground.
Being unpractical or would cost to much, have nothing to do with the regs.

 

steptoe

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cant you just put it in the bathroom and protect it with a 30mA RCD?

no bonding required!!!

agree with Slips tho, money or practicality dont matter if safety is concerned!

 
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