Introduction to Health and Safety at Work

Figure 12.7
Transformer, RCD and isolators.
Figure 12.8
Multiplugs, extension lead and special plugs 
and sockets.
Figure 12.9
Double insulation sign.

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Electrical hazards and control
197
12.6 
Inspection and maintenance 
strategies
12.6.1 Maintenance 
strategies
Regulation 4(2) of the Electricity at Work Regulations 
requires that ‘as may be necessary to prevent danger, all 
systems shall be maintained so as to prevent so far as is 
reasonably practicable, such danger’. Regular mainten-
ance is, therefore, required to ensure that a serious risk 
of injury or fi re does not result from installed electrical 
equipment. Maintenance standards should be set as high 
as possible so that a more reliable and safe electrical 
system will result. Inspection and maintenance periods 
should be determined by reference to the recommenda-
tions of the manufacturer, consideration of the operating 
conditions and the environment in which equipment is 
located. The importance of equipment within the plant, 
from the plant safety and operational viewpoint, will also 
have a bearing on inspection and maintenance periods. 
The mechanical safety of driven machinery is vital and 
the electrical maintenance and isolation of the electric-
ally powered drives is an essential part of that safety.
The particular areas of interest for inspection and 
maintenance are:
➤
the cleanliness of insulator and conductor surfaces
➤
the mechanical and electrical integrity of all joints 
and connections
➤
the integrity of mechanical mechanisms, such as 
switches and relays
➤
the calibration, condition and operation of all protec-
tion equipment, such as circuit breakers, RCDs and 
switches.
Safe operating procedures for the isolation of plant and 
machinery during both electrical and mechanical main-
tenance, must be prepared and followed. All electrical 
isolators must, wherever possible, be fi tted with mech-
anisms which can be locked in the ‘open/off’ position 
and there must be a procedure to allow fuse withdrawal 
wherever isolators are not fi tted.
Working on live equipment with voltages in excess of 
110 V must not be permitted except where fault fi nding or 
testing measurements cannot be done in any other way. 
Reasons, such as the inconvenience of halting produc-
tion, are not acceptable.