Sterling MS - Manual (Page 28)

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PROBLEM PROBABLE CAUSE SOLUTION
3. Motor runs and then Partial loss of line voltage. Check for loose connections.
dies down.
Determine adequacy of main power supply.
4. Motor does not Motor undersized for application. Replace with larger motor.
come up to speed.
Voltage too low at motor terminals. Check across AC line and correct if possible.
Line wiring to motor is too small. Install larger line wiring.
5. Motor takes too long Excessive load. Replace with larger motor.
to accelerate. Loose connection. Check connections and tighten where necessary.
6. Wrong Rotation (3 Phase) Improperly wired to AC line (wrong Check unit wiring diagram. Reverse any two line
sequence of phases). voltage connections.
7. Motor Overheats Motor overloaded. Replace with larger motor.
Motor ventilation clogged. Clean motor.
Motor (3 phase) may have open phase. Check to insure that all connections are tight.
Line voltage too high or too low. Check across AC line and correct if possible.
Worn blower bearings. Replace blower bearings.
8. Motor Vibrates Motor mounting bolts loose. Tighten mounting bolts.
Driven equipment unbalanced. Balance driven equipment.
Worn motor bearings. Replace motor.
3 phase Motor running on single phase. Check for open circuit and correct.
Bent motor shaft. Replace motor.
9. Rapid Motor Bearing Excessive overhung load due to over Reduce belt tension.
Wear
tensioned belt.
TROUBLESHOOTING GUIDE
FAN ASSEMBLY
PROBLEM PROBABLE CAUSE SOLUTION
1. Short Belt Life Spin burns from belt slippage. Tension belt.
High ambient temperature. Use Gripnotch belts.
Grease or oil on belts. Clean belts and pulleys.
Worn pulleys. Replace pulleys.
Belt Misalignment. Realign drive.
2. Belts turn over in grooves Damaged belt. Replace belt.
Excessive vibration. Tension belts. Replace belts if damaged.
Worn pulleys. Replace pulleys.
Pulley Misalignment. Realign drive.
3. Belt Squeal Excessive load. High starting load.Retension drive.
4. Belt Breakage Foreign material in drive. Provide drive guard.
Belts damaged during installation. Replace belts.
Extreme Overload. Eliminate overload.
5. Excessive Vibration Damaged belt cord section. Replace belts.
Loose belts. Tension drive.
Belts improperly tensioned. Tension drive with slack of each belt on the
same side of drive.