LEESON NEMA 4X SCR Control: 174903.00 (Obsolete) - Manual (Page 15)

14
Motor doesn't operate
Motor stalls, or runs
very slowly with speed-
pot turned fully CW
Motor hunts
Repeated fuse blowing
Motor runs but will not
stop
- blown fuse
- incorrect or no power source
- speedpot set at zero
- worn motor brushes
- low voltage
- overload condition
- worn motor brushes
- max speed set incorrectly
- too much I.R. Comp.
- motor is in current limit
- motor not pulling enough
current
- max trimpot set too high
- motor speed is above rated
speed
- low voltage
- overload condition
- worn motor brushes
- defective motor bearings
- defective electrical component
- incorrect wiring
(enclosed version)
- defective wiring
- defective component
replace fuse
install proper service
adjust speedpot CW to start
replace motor brushes
check - should be above 108V
reduce load
replace motor brushes
see ADJUSTMENT PROCEDURE
see ADJUSTMENT PROCEDURE
see ADJUSTMENT PROCEDURE
current must be greater than 150 mA D.C.
see ADJUSTMENT PROCEDURE
reduce speed
check - should be above 108V
reduce load
replace
replace
call LEESON Distributor / Representative
check TERMINAL STRIP WIRING for
correct wiring instructions (note AC line
connection in particular)
check wiring
call LEESON Distributor / Representative
If a newly installed control will not operate, it is possible that a terminal or connection is loose.
Check to make sure that all connections are secure and correct. If the control still doesn't
operate, refer to the following chart:
PROBLEM POSSIBLE CAUSE(S) CORRECTIVE ACTION(S)
If control still will not operate, consult your LEESON Distributor or Representative.
IN CASE OF DIFFICULTY