80459-641-01E Model 6 Motor Control Centers
10/2012 Section 11—Troubleshooting
© 1999–2012 Schneider Electric All Rights Reserved
103
ENGLISH
TeSys T
Wiring/configuration
errors
CT reversal error
Correct the polarity of the CTs. Be sure that:
• all external CTs face the same direction
• all load CT wiring passes through windows in the same
direction
After all checks are complete:
1. Perform a fault reset.
2. If the fault persists, cycle power and wait 30 s.
3. If the fault still persists, replace the TeSys T.
Current/voltage phase reversal error Check:
• L1, L2 and L3 wiring connection to be sure wires are not
crossed
• Motor Phases Sequence parameter setting (ABC versus ACB)
After all checks are complete:
1. Perform a fault reset.
2. If the fault persists, cycle power and wait 30 s.
3. If the fault still persists, replace the TeSys T.
Phase configuration error
PTC connection error
Check for:
• short circuit or open circuit in the motor temp sensor wiring
• wrong type of motor temp sensing device
• improper configuration of parameters for selected device
After all checks are complete:
1. Perform a fault reset.
2. If the fault persists, cycle power and wait 30 s.
3. If the fault still persists, replace the TeSys T.
Voltage phase loss error
Check for:
• improper wiring, such as loose terminations
• blown fuse
• cut wire
• single-phase motor configured for 3-phase operation
• failure to wire a single phase motor through both A and C load
CT windows
• failure of power source (for example, utility power failure)
After all checks are complete:
1. Perform a fault reset.
2. If the fault persists, cycle power and wait 30 s.
3. If the fault still persists, replace the TeSys T.
Magnetic And
Mechanical Parts
Noisy Magnet
1. Broken shading coil. 1. Replace the magnet and armature.
2. Dirt or rust on magnet faces. 2. Clean the magnet with a clean, dry cloth.
3. Low voltage. 3. Check the coil terminal voltage and voltage dips during starting.
Failure To Pick Up and
Seal
1. No control voltage.
1. Check the control circuit wiring for a loose connection or poor
contact continuity.
2. Low voltage.
2. Check for the proper coil terminal voltage and voltage dips
during starting.
3. Mechanical obstruction.
3. With the power off, check for free movement of the contact and
armature assembly.
4. Open or overheated coil. 4. Replace the coil.
5. Wrong coil. 5. Replace the coil.
Failure To Drop Out
1. Gummy substance on the pole faces. 1. Clean the pole faces with a clean, dry cloth.
2. Voltage not removed. 2. Check the coil terminal voltage and the control circuit.
3. Worn or corroded parts causing binding. 3. Replace the parts.
4. Residual magnetism due to the lack of an
air gap in the magnet path.
4. Replace the magnet and armature.
5. Welded contacts. 5. See Contacts—Welding or Freezing
Pneumatic Timers
Erratic Timing Foreign matter in the valve.
Replace the complete timing head, or return the timer to the factory
for repair and adjustment.
Contacts Do Not
Operate
1. Maladjustment of the actuating screw. 1. Adjust according to the instructions in the service bulletin.
2. Worn or broken parts in the snap switch. 2. Replace the snap switch.
Limit Switches Broken Parts Overtravel of the actuator.
Use a resilient actuator, or operate within the tolerance of the
device.
Manual Starters Failure To Reset Latching mechanism worn or broken. Replace the starter.
Table 17: Motor Control Center Troubleshooting Chart (continued)
Part Problem Cause Remedy
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