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© Copyright 2013 Simpro Handling Equipment Ltd
Electrical:
Risk Event: The contacts on (one of) the motor contactor(s) could fuse or weld, so the
motor does not stop when the Raise button is released.
Control Method: Provision of an isolating switch either on the machine or nearby allows the power supply to be
turned off quickly, stopping the motor.
The system will go into Safe mode and cannot be reset until the fault has been remedied.
Pressing the E-Stop puts the machine into Safe mode and stops the motor running.
Risk Event: A wire could come off the coil of (one of) the motor contactor(s), or a
switching wire could come off, or a complete contact block could fall off the
‘Raise’ switch.
Control Method: In all these situations the contactor will not operate, and the cradle cannot be raised. The
machine cannot be used until the fault has been remedied.
Risk Event: A wire could come off (one of) the contactor auxiliary contact(s).
Control Method: The system cannot be reset and the machine cannot be used until the fault has been
remedied.
Risk Event: The contacts in the Raise switch could jam in the ‘On’ position
Control Method: Provision of an isolating switch either on the machine or nearby allows the power supply to be
turned off quickly, stopping the motor.
The machine cannot be used until the fault has been remedied.
Pressing the E-Stop isolates the signal to the contactor and stops the motor running.
Risk Event: The contacts in the Lower switch could weld together or jam in the ‘On’
position
Control Method: Provision of an isolating switch either on the machine or nearby allows the power supply to be
turned off quickly, which will close the lowering valve.
The fault must be remedied before the machine can be used again.
Pressing the E-Stop isolates power to the lowering solenoid.
Risk Event: A switching wire could come off, or a complete contact block could fall off a
‘Lower’ switch, or the plug could come off the solenoid, or the solenoid could
come off the valve.
Control Method: In all these situations the lowering valve will not operate, and the cradle cannot be lowered.
The machine cannot be used until the fault has been remedied.
Risk Event: Electrocution from the supply lead.
Control Method: The power supply lead should have an RCD fitted. Power leads should come down from above
where possible.
If not possible, leads should be as short as possible, and must be protected from damage by
vehicles, heavy and/or sharp objects falling on them, and persons tripping on them.
Leads should be regularly checked and tagged by a registered electrician, and replaced if there
are any signs of damage to the insulation.
Summary:
MegaDumpers are inherently very safe machines due to their design and method of operation.
Guarding prevents access to all moving parts during operation.
Safety devices may be monitored to Cat3 level or higher as required.