6.8.2 Connecting the Power Supply
The connection of the power supply should always be carried out by an appropriately qualified electrician or person competent to carry out such work.
The power supply must be taken via fuses, or other protective devices, rated in accordance with the hoist manufacturer’s instructions and must include a means of isolating the hoist from the power source.
In the case of an enclosed conductor supply, ensure that the collectors align correctly with the conductors. If spring loaded collectors are fitted, they should be compressed by the conductors to approximately half of their full movement.
In the case of a cable supply, care must be taken to ensure sufficient cable is used so as to allow the hoist to travel to its furthest point from the power source without the cable coming under tension. It is good practice for the earth wire to be longer than the live wires so if there is excessive tension on the cable, which pulls a live wire from its terminal, the earth wire will still be attached.
Before connection of the power supply, insulation resistance, polarity and earth continuity tests should be carried out and care taken not to damage any low voltage circuits or electronic devices.
After connection of the power supply, check the direction of the motions, that is when the ‘down’ button is depressed - hook hoist lowers, when the ‘up’ button is depressed - hook hoist rises. This is especially important in the case of plug in connections, as the phasing at the socket is not guaranteed. If the direction of motion is incorrect, disconnect the mains supply and either reverse two phases at the hoist entry terminals or change over two phases at the fuse box. Under no circumstances should any other changes be made. Some hoists may be fitted with phase protection equipment which prevents the hoist operating if the phases are incorrectly connected.
Hoists that incorporate power travel trolleys should be checked in a similar way to ensure that the travel motion is in the selected direction. In the case of hoists controlled by non-conductive controls, it is advisable to mark the hoist clearly with symbols to show the travel control direction, e.g. East - West. The control unit should be marked in an identical way. This is necessary as the operative may be positioned on either side of the unit when operating the travel motion.