Bumping a motor means pressing start and stop almost together so the shaft turns only a few degrees, enough to see which way it spins. It is standard after new terminations or any change to the supply, because a pump, compressor or conveyor driven backwards can be damaged. If the direction is wrong, any two of the three phases are swapped at the motor or the starter.
Bump the cooling tower fan before you let it run, we just moved the feed onto the new cable.
Also heard as
- bump test
- jog
Related terms
Slip
Shortfall between the speed of an induction motor's rotating field and the actual speed of its rotor.
Inrush current
Large transient current drawn when a transformer, motor or capacitive load is first switched on.
Ring out
To check continuity and identity of every core of a cable end to end before termination or after a fault.
Same word, different worlds
To make a small adjustment to an offset or position, usually a thou or less, to bring a size in.
Boilers & BurnersTo energize a motor, pump or burner for a second or two to check rotation or operation.
Lighting & Color ScienceTo flash a channel or group to full instantly, usually with a console button, to identify it or for effect.
Asphalt PavingTo push excess mix off the old side of a joint back onto the hot mat with a lute so the rollers can pinch it in.
RailroadingTo use seniority to take a job held by someone junior, who is then displaced.