Direct on Line Motors versus Low Voltage Control
For most rigging there are two types of motors used for rigging lifting. Direct On Line and Low Voltage Control. Low voltage control is where either the mains power is applied to the motor all of the time or switched when the GO button is pressed and direction controlled by using a low voltage supplied by the motor and controlled by relays in the controller or by a hand held pendant or “Pickle”. These motors generally have limit switches on board to set the maximum/minimum of the motors lift and use two motor cables one red Ceeform for power and one yellow Ceeform for control. Direct on Line or DOL switch the power to the motor from the controller changing the phase supply to alter the direction and use one red Ceeform Cable, there is normally no top or bottom limit switches but chain stops can be used to achieve a similar effect. Direct on Line rely more on operator skill and experience but are able to be used in situations where low voltage can’t be including extended chain length and reversed phase situations. Juice Rigging use DOL Chainhoists for most situations as our riggers are trained and have the experience and we use them in unusual situations where Low Voltage could not be used. There are benefits to both types.
Wet Chain Versus Dry Chain
The difference in these two modes is where the chain is kept oiled or not. In a dry chain situation the chain is allowed to run dry. This means that oil does not get onto fabrics or scenery, hands, clothing etc. However the down side is that there is vastly increased wear on the chain, chain guides and chain pulley and so motor rental charges have to higher to accommodate this increased cost. In a Wet Chain situation the chains are kept lightly oiled, decreasing wear on all components, minimising chain jams and enabling use outdoors with minimal corrosion. Juice Rigging has a wet chain policy.