Page 18
TROUBLE
REMEDY
Hook Raises But Will Not Lower When Motor is Operating.
Consult Factory Or Authorized Duff-Norton Warranty Repair Station.
Hook Lowers But Will Not Raise
1. Hoist overloaded.
2. Low voltage.
3. "UP" circuit open.
4. Broken conductor in pushbutton cable.
5. Faulty magnetic hoist control switch.
6. Faulty capacitor (single-phase hoists only).
7. Worn overload limiting clutch.
1. Reduce load to within rated capacity.
2. Determine cause of low voltage and bring up to at least 90% of the
voltage specified on hoist. Line voltage should be measured while
holding or lifting load.
3. Check circuit for loose connections. Check "UP" limit switch for
malfunction.
4. Check each conductor in the cable. If one is broken, replace entire
cable.
5. Check coils for open or short circuit. Check all connections in
control circuit. Check for burned contacts. Replace as needed.
6. Check starting capacitor in motor. Replace if necessary.
7. Replace clutch.
Lack of Proper Lifting Speed
1. Hoist Overloaded
2. Motor brake is dragging.
3. Low voltage.
4. Overload limiting clutch intermittently
slipping.
1. Reduce load to within rated capacity of hoist.
2. Check for proper brake adjustment or other defects.
See paragraph 5-3.
3. Bring up voltage to plus or minus 10% of voltage specified on hoist.
Line voltage should be measured while hoist is lifting load.
4. Replace clutch.
Load Brake "Noise" (Erratic tapping sounds or squeals)
1. Need transmission oil change or improper
lubricant has been used.
2. Load brake malfunctioning.
1. Change transmission oil. See Table 5-1.
Note: Hoist Warranty is void if unapproved oil is used.
2. Check load brake operation. See paragraph 4-4.
Motor Brake Noise or Chatter (While starting hoist)
1. Brake needs adjustment.
2. Low voltage.
1. Adjust as per paragraph 5-3.
2. Check voltage at hoist power cord with hoist starting. Voltage should
be no less than 90% of the voltage specified. 115 volt hoists are
particularly subject to voltage drop problems due to their high current
draw. Conversion to 230 volt operation is suggested in extreme cases.
Motor Brake "Buzz" (Anytime hoist is running)
1. Brake needs adjustment.
2. Broken shading coil on brake frame.
1. Adjust as per paragraph 5-3.
2. Replace shading coil or complete brake frame assembly.
For more information contact: Sievert Crane and Hoist, (708) 771-1600, parts@sievertelectric.com, www.sievertcrane.com