Introduction to Health and Safety at Work

11.14.3 Hold-to-run 
control
This is a control which allows movement of the machin-
ery only as long as the control is held in a set position. 
The control must return automatically to the stop pos-
ition when released. Where the machinery runs at crawl 
speed, this speed should be kept as low as practicable.
Hold-to-run controls give even less protection to the 
operator than two-handed controls and have the same 
Figure 11.15
Typical sliding and hinged interlocking guards.

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Work equipment hazards and control
177
main drawback in that they give no protection to anyone 
other than the operator.
However, along with limited movement devices 
(systems which permit only a limited amount of machine 
movement on each occasion that the control is operated 
and are often called ‘inching devices’), they are extremely 
relevant to operations such as setting, where access may 
well be necessary and safeguarding by any other means 
is diffi cult to achieve.
11.15 
Application of safeguards to the 
range of machines
The application of the safeguards to the Certifi cate range 
of machines is as follows.
Offi ce – photocopier
Application of safeguards (Figure 11.18)
➤
the machines are provided with an all-enclosing case 
which prevents access to the internal moving, hot or 
electrical parts
Figure 11.16
Schematic diagram of a telescopic trip device fi tted to a redial drill.
Figure 11.17
Pedestal mounted free-standing two-hand 
control device.
Figure 11.18
Typical 
photocopier.

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Introduction to Health and Safety at Work
178
➤
the access doors are interlocked so that the machine 
is automatically switched off when gaining access to 
clear jams or maintain the machine. It is good prac-
tice to switch off when opening the machine
➤
internal electrics are insulated and protected to pre-
vent contact
➤
regular inspection and maintenance should be car-
ried out
➤
the machine should be on the PAT (portable elec-
trical testing) schedule
➤
good ventilation in the machine room should be 
maintained.