John asks this question, which concerns an EICR for air conditioning supplies that use SY braided cable with plastic glands. It has been answered by SELECT (Theme – Regulations and Legislation):
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Question: I’ve been asked to do an EICR on a commercial electrical installation. After having a quick look around I noticed the air conditioning (three-phase) supply was in SY braided cable and, as far as I understood, this needed to be earthed using the correct SY metal gland. However, a plastic gland had been used.
My question is for both existing and new installations using SY cable. On existing installations using SY cable that have a plastic gland fitted, is this OK? Only the metal sheath is not earthed.
What would the recommendations be for this - e.g. what Code? Install a metal gland? Or add an RCD?
On new installations, should metal glands be used, or RCDs when using SY cable? Which is best?
Finally, specialist air conditioning installers quite often carry out installations like this one. Do they have to comply with different regulations?
Answer: SY cables are used fairly frequently for this type of installation. Plastic glands can be used – however, it is advisable at least to ensure that the braiding is secured to earth on at least one end of the cable run if using a TN earthing system.
On existing installations, when preparing an EICR, providing that the equipment is provided with a suitable earth connection via a circuit protective conductor (CPC) in the cable, a Code 3 should suffice.
The manufacturer's information should also be considered.
Air condition engineers, when carrying out electrical installations, should also comply with BS 7671, as amended.
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