Ask the experts/Technical
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We continue with our series of answers to some of the more frequently asked questions put to our Technical Helpline.
QUESTION
ANSWER
Are there any specific requirements given in BS 7671 that need to be considered when carrying out work in a dental practice?
Yes, dental practices are to be considered as medical locations, as defined in Section 710 – Medical Locations. While complying with the general requirements of BS 7671, it is likely that parts of Section 710 will amend or add to some of those general requirements. Prior to any decisions taken on the particular regulations that may apply, the contractor will need to agree with the client the nature of the work that will be carried out: such work will indicate both the classification and the group. Annex A710 provides guidance on group numbers and classification for safety services of medical locations (Regulation 710.3 refers).
QUESTION
ANSWER
After carrying out either an addition or alteration to an existing installation, is it necessary to affix a periodic inspection and testing notice?
It may be appropriate for a notice advising the user of the recommended date of the next inspection and testing of the circuits that have been subjected to additions or alterations to be fixed at or near the origin of the installation, as required by Regulation 514.12.1; for example, where no current notice exists. However, there is a risk of confusion for the user, where more than one periodic inspection and testing notice is affixed. Where there is an existing notice and such confusion could arise, the contractor should err on the side of safety and not affix a second notice.
QUESTION
ANSWER
Is it permitted to extend an existing main protective bonding conductor?
Yes. However, the connection must be a ‘permanent connection’, such as a connection made by soldering or a compression tool. This is to minimise the risk of the connection becoming detached with a consequent loss of continuity. This effectively precludes making the connection by an earthing and bonding clamp to BS 951 (Regulation 528.3.3 refers). Connections Summer 2016
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