BS 7671 Amendment 4: Medical Locations (Section 710)

Group 0, 1, and 2 Classifications

Section 710 classifies medical locations into three groups based on the type of applied part and the risk to patients. Group 0 covers locations where no applied parts are used (e.g., waiting rooms). Group 1 includes locations where applied parts may be in contact with the patient externally (e.g., examination rooms). Group 2 is the highest classification, covering locations where applied parts are used for intracardiac procedures or where discontinuity of supply could cause danger to life (e.g., operating theatres, intensive care units).

Amendment 4 clarifies the classification boundaries and provides updated examples reflecting modern medical practice. The revision aligns with IEC 60364-7-710 and harmonises UK requirements with international best practice.

Supplementary Bonding

The revised Section 710 updates the supplementary bonding test schedule for Group 1 and Group 2 locations. In Group 2, the resistance between simultaneously accessible extraneous-conductive-parts and the equipotential bonding busbar must not exceed specified values. Amendment 4 revises the test methodology and clarifies which conductive parts must be included in the bonding network.

Supply Continuity & IT Systems

Group 2 locations require IT (isolating transformer) systems for circuits supplying life-support equipment. Amendment 4 revises the requirements for insulation monitoring devices (IMDs), changeover times for standby supplies, and the configuration of medical IT systems. The update addresses the increasing complexity of critical power distribution in modern hospitals.

IEC 60364-7-710 Alignment

A key objective of the Section 710 revision is closer alignment with IEC 60364-7-710. This benefits multinational healthcare projects and medical equipment manufacturers operating across jurisdictions. The harmonised requirements reduce conflicts between UK and international standards for medical electrical installations.