4
Installation
44
07.2020
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4.9.10
Overload safety device
The wire rope hoist is supplied with an overload protection.
Description of system
The overload safety device is a device which automatically prevents the hoist moving
loads exceeding its safe working load during normal operation, taking into account the
dynamic effects. This is achieved by measuring the force transmitted with the aid of a
sensor and cutting the energy supply to the hoist drive and brake (stopping the hoist
motion) (indirect-acting overload protection). In hoist controls the overload protection
(safety-related function) is provided by various components (SRP/CS). The point of
departure is where the safety-related signals are generated and the endpoint is the output
of the power control elements. The electronic control device (SLE/SMC) acts as a safety
device.
The protective devices of the electrical equipment installed in the scope of supply must in
no case be removed, replaced by different devices or bridged.
Fig. 38
Load sensor Safety device Contactor or inverter
control
Fig. 39
Load measurement at rope anchorage
(reevings: 2PS, 4PS, 2PD, 4PD)
with electronic pressure sensor
The overload safety device is set to maximum working load +10%.
Fig. 40
Load measurement at gear
(reevings: 1PS, 1PD)
with electronic shear force sensor
The overload safety device is set to maximum working load +10% overload.
Fig. 41
NOTICE
On YKB/SKB and YKC/SKC wire rope hoists with 1PS and 1PD reevings, remove the
transport anchor screws marked in red after installation and before commissioning.
W0788