4 Troubleshooting
Error Condition
Incomplete
Sequence
External Trip
CPU Fault
Troubleshooting Guide
Main Cause |
| Remedy |
Indicates the | 1. If the unit trips one second after start, verify that | |
detect current one second after a start |
| current transformer secondary input is present in the |
command, or it detects current one |
| range of 100 mVAC to 3.54 VAC at terminals 1, 2, |
second after a stop command. |
| and 3 with reference to 4. Verify that the coil voltage |
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| is 115 VAC at terminals 14, 15, or 16 with reference |
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| to 13 when the motor is started. Verify 115 VAC at |
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| terminal 7 with reference to 13. Correct conditions if |
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| necessary. Call Siemens if unit continues to trip. |
| 2. If the unit trips one second after a stop command, | |
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| verify the contactor is open. Repair or replace the |
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| contactor if it is not functioning properly. |
| 3. Verify operation of mechanical interlock, and replace | |
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| or adjust. |
| 4. Verify absence of voltage at terminals 1, 2, and 3 with | |
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| reference to 4, and at terminals 14, 15, or 16 with |
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| reference to 13. If voltage is present, define the |
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| source and reconnect so that the motor current only |
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| passes through the current transformer. |
| 5. To disable incomplete sequence, select F1 on the | |
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| HHC, press the ENTER key for one or more seconds |
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| and start the motor. The incomplete sequence will |
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| remain disabled until the above procedure is |
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| repeated. |
If the external trip LED is solidly | 1. Jam conditions such as a blocked conveyor belt or | |
illuminated and the motor is stopped, it |
| gear train cause a sudden increase in motor current, |
indicates a jam or loss of load |
| which can damage the motor’s insulation in a short |
condition. |
| period of time. |
| 2. Loss of load conditions, such as a broken blade of an | |
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| impeller or loss of back pressure of a pump, result in |
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| a sudden decrease in motor current. |
| 3. F16 on the HHC displays the external trip current at | |
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| the time of the trip. |
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| In any case, determine the reason for the external trip |
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| and correct the problem before restarting the motor. |
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| If the external trip LED flashes and the motor |
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| continues to run, it indicates loss of load warning or |
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| process current warning. |
Indicates a problem in the |
| Verify voltage between terminals 5 and 6 is more than |
microprocessor or a low voltage |
| 10 VAC. If fault persists, call Siemens. |
condition. |
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