Coffing Hoists EC Series, Operating, Maintenance & Parts Manual

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P/N EC680-7 April 2017
Order # 5041558-0 & 5041679-0
SECTION VI TROUBLESHOOTING
Problem Probable Cause Remedy
Lack of Proper
Lifting Speed.
1. Hoist overloaded. 1. Reduce load to within rated capacity of hoist.
2. Motor brake is dragging. 2. Check for proper brake adjustment or other defects. Sec paragraph 5-3.
3. Low voltage. 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. Overload limiting clutch intermittently slipping. 4. Replace clutch,
Load Brake
“Noise.” (Erratic
tapping sounds
or squeals)
1 . Need transmission oil change, or improper lubricant has
been used.
1. Change transmission oil. Sec Table 5-1. Note: Hoist Warranty is void if
unapproved oil is used.
2. Load brake malfunctioning. 2. Check load brake operation. See Figure 4-3.
Motor Brake
Noise or Chatter.
(While starting
hoist)
1. Brake needs adjustment. 1. Adjust as per paragraph S-3.
2. Low voltage. 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. 1. Adjust as per paragraph 5-3.
2. Broken shading coil on brake frame. 2. Replace shading coil or complete brake frame assembly.
* A more detailed explanation of electronics troubleshooting can be found with the CM interface cable kit. This procedure requires use of
extracted fault codes from the hoist memory, plus multimeter readings.
SECTION VII WIRING
SAFETY NOTES
Disconnect power from hoist before removing end covers.
7-1. WIRING DIAGRAMS
The wiring diagrams for standard hoist models are reproduced on
the following pages. In addition, every hoist should have a wiring
diagram located inside the long end cover.
7-2. VOLTAGE CONVERSION
Standard single phase units are convertible from 115 to 230 volts,
and standard single speed three phase units are convertible from
460 to 230 volts. Conversion to the alternate voltage can be
accomplished with the following procedure.
a. Be sure power is disconnected from hoist. Remove long end
cover.
b. SINGLE PHASE HOISTS (with SINPAC® switch): Transfer leads
per the appropriate terminal block schematic.
c. THREE PHASE HOISTS: Transfer leads per the appropriate
terminal block schematic.
Do not move any wires or make any changes to the wiring
except at the terminal block.
After converting voltage, check for proper phasing of three
phase units and check for proper limit switch operation.