Pulsafeeder PULSAmatic 7120, Installation, Operation, & Maintenance Instruction

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9. Troubleshooting
PROBLEM PROBABLE CAUSE
Actuator Does Not Adjust
1. No AC power to actuator.
2. Pump not running.
3. Override switch not pushed in.
4. Control signal off, incorrect, or of inverted polarity.
5. Ratio control (if so equipped) set at or very near zero percent.
6. Blown fuse (see Figure 4 for location).
7. Wiring discontinuity.
8. Brake slipping (see “Troubleshooting”).
9. Defective feedback potentiometer (see “Repairs”).
10. Circuit board malfunction.
11. Broken actuator linkage.
12. Brake drive nut damaged.
Actuator Adjusts to
Incorrect Setting
1. Control signal incorrect or of inverted polarity.
2. Incorrect ratio control setting (if so equipped).
3. Circuit board out of calibration (if so equipped). (See “Calibration”).
4. Actuator misaligned to pump (see “Repairs”).
5. Defective feedback potentiometer (see “Repairs”).
6. Defective feedback potentiometer (see “Repairs”).
7. Limit switch out of adjustment (see “Repairs”).
8. Circuit board malfunction.
Actuator Adjusts in One
Direction Only
1. Control signal incorrect or of inverted polarity.
2. Incorrect ratio control setting (if so equipped).
3. Wiring discontinuity.
4. Brake slipping (see “Troubleshooting”).
5. Defective feedback potentiometer (see “Repairs”).
6. Limit switch out of adjustment (see “Repairs”).
7. Circuit board malfunction.
8. Defective brake.
Brake Slipping
1. Jammed slider block (see “Repairs”).
2. Circuit board malfunction (inadequate power to the brake).
3. Brakes misaligned.
4. Improper brake air gap (see “Repairs”).
5. Brake friction surface contaminated with oil or other foreign material.
Erratic Operation
1. Wiring discontinuity.
2. Narrow deadband (see “Calibration”).
3. Erratic control signal.
4. Noisy controls signal (check grounding and shielding of controls
signal leads).
5. Defective feedback potentiometer (see “Repairs”).
6. Brake slipping (see “Troubleshooting”).
7. Brake dragging (check brake alignment and air gap, see “Repairs”).
8. Circuit board malfunction.