18 Magnetic lifting devices1
18.1.1. The voltage of the electric supply to any magnetic lifting
device should not fluctuate by more than ± 10 per cent.
18.1.2. (1) A magnetic lifting device should be provided with
an alternative supply of power, i.e. batteries that come into operation
immediately in the event of failure of the main power; provided that
this subparagraph need not apply to a magnet that is being used to
load or unload scrap metal or to other cargo-handling operations of
such a nature that there is no person in the vicinity other than the
driver of the lifting appliance.
(2) A magnetic lifting device should be so constructed as to
withstand the entry of moisture.
18.2.1. A magnetic lifting device should be thoroughly examined
in accordance with the requirements of Appendix C.
18.3. Safe working load
18.3.1. (1) A magnetic lifting device should be marked with its
safe working load as determined by tests using weights of the same
characteristics as the load for which the device is intended to be used.
(2) When the load to be lifted is dissimilar to the test load, it
should be restricted to approximately 60 per cent of the safe working
18.4. Precautions when in use
18.4.1. (1) The power to the magnet should not be switched on
until after the magnet has been lowered on to the load to be lifted.
1See also sections 4.2, 17.7 and 20.6, which are applicable.