Bonding in Hot Presses

The main items queried appears to be that SEAI have been awarding Penalty Points to Heating Contractors for the absence of a 10sq bonding cable in the hot press, even where the entire installation is carried out in Qualplex, or other non-conducting points.

 

There is no Rule in ET101 which calls for this bonding requirement and it is therefore unacceptable that contractors should be penalised for carrying out their installations in accordance with the ETCI National Wiring Rules.

 

On page 126 of ET207, The Guide to the National Wiring Rules as published the Electro Technical Council of Ireland (ETCI), it is clearly stated that:

 

 

In this context the Cylinder in the Hot Press falls into the same category and need not be bonded as any short stubs of copper to which the plastic pipes are connected are deemed to be all part of the tank from an electrical conductivity point of view.

 

Additionally, on page 126, ET207 states that direct connection of a bonded system to the main earth terminal has not been a requirement since the year 2000.

 

In fact it is now regarded as undesirable to attach a bonding or earth conductor to an isolated metal object, such as the cylinder in this case, in that by doing so you are introducing a path by which an electrical charge could become present on metal, which, in the absence of the earth conductor, would have no possible means of generating or becoming charged with voltage.

 

If an electric immersion heater is fitted to the cylinder it must of course be earthed, as is the case with every electrical appliance, but the earth in the circuit supplying the immersion heater is deemed to be sufficient for compliance with ETCI Wiring Rules.

 

Where the installations which are the subject of these complaints from SEAI are carried out in its entirety in Qualplex, or other non-conducting pipes, the need for bonding or earthing in the hot-press does not arise and should in fact be avoided for the reasons set out earlier.