R&M Materials Handling ELECTRIC CHAIN HOISTS LoadMate Chain Hoist TDU Motorized Trolley - Manual (Page 18)

R&M Materials Handling, Inc LoadMate Chain Hoist
Springfield, Ohio USA TDU Instruction Manual
(: 800 955-9967 Revision 2
web: www.rmhoist.com
08/13/02 RM-LM-TDU-MAN-1999-2-ENG.doc 18
Trouble Shooting
Trolley operates for 2 seconds then stops:
ü Control unit is not receiving pulses from the pulse sensor
ü Sensor in the wrong position or defective Þ position it correctly or replace it
ü Toothed disk is defective Þ
replace it.
Trolley accelerates very fast then stops
ü Press the emergency stop. Check that there is no risk of collision and start the trolley again.
ü If the same thing happens again, STOP THE TROLLEY AND REPLACE THE CONTROL UNIT
TDU Brake does not open
ü Check the air gap and look for other possible mechanical problems
ü Check the brake cable connections
ü Disconnect the control unit cables. Check the brake coil resistance (1500 to 1540 Ohm) and the
insulation resistance (>1 Mohm). If the resistance is defective, replace the brake.
ü Measure the voltage between terminals 13 and 14 while the unit is operating. It should be between 160
and 200 VDC. If not, the control unit is defective and should be replaced. If encountering difficulty when
measuring the voltage while the trolley is running, disconnect the blue and white wire from the terminal.
In this case the voltage is possible to be measured only within 2 seconds.
Brake cannot be released:
ü Air gap badly adjusted
Þ adjust it
ü Presence of foreign matter Þ clean it
ü Mains voltage too low Þ
revise it
Insufficient braking torque:
ü Grease on lining
Þ replace lining
ü Damaged lining Þ replace lining
ü Sliding of armature and disc Þ clean, replace if necessary
If the trolley moves to the wrong direction of the push button being pressed, invert the cables (blue and white)
of the rotor.