Westinghouse DS/DSL series low-voltage power circuit breakers

Electric energy storage: Connect the control power supply, the circuit breaker automatically stores energy, observe that the energy storage motor runs normally, and the energy storage time is ≤ 30 seconds.

Closing/tripping test (test position):

Manual closing: Press the closing button to close the circuit breaker, the closing indicator light will light up, and the contacts will be closed in place; Press the trip button, the circuit breaker trips, the trip indicator light lights up, and the action is smooth without any jamming.

Electric closing/tripping: Through remote control signal testing, confirm that the action response is timely (≤ 0.5 seconds) and there is no misoperation.

Release unit test:

Long delay test: Use a dedicated testing kit to input 1.25 times the rated current of the sensor and verify that the trip time meets the set value (8-36 seconds).

Short delay test: Input 6 times the rated current of the sensor and verify the trip time of 0.18-0.5 seconds.

Instantaneous test: Input 10 times the rated current of the sensor to verify instantaneous tripping.

Grounding fault test (I-A type): Input the set grounding current, verify the delayed tripping and indicator action.

Interlocking function test:

Attempt to switch to the open position while in the closed state, and confirm that the interlock prevents action.

Extract the position and attempt to store energy, confirming that the energy storage mechanism is interlocked and locked.

Padlock test: Hang the lock in the tripped position and confirm that it cannot be closed.

3. Daily maintenance and regular maintenance

(1) Daily maintenance

Cleaning: Use a dry cloth to wipe the dust on the surface of the circuit breaker, and use compressed air (pressure ≤ 0.4MPa) to blow and sweep the arc extinguishing chamber vent and contact area. Do not use solvents for cleaning.

Check:

Appearance: The contacts are not eroded or deformed, the arc extinguishing chamber is not damaged or carbonized, and the interlocking components are not loose.

Indicator lights: The status of energy storage, closing, and tripping indicator lights is consistent with the actual situation.

Wiring: There is no looseness, heating or discoloration in the wiring of the main circuit and control circuit.

Functional testing: Manually close/trip once each to verify smooth operation; Test GFCI leakage protection function (once a month).

(2) Long term storage and maintenance (not used for more than 3 months)

Preparation before storage:

Release the energy storage spring and disconnect the main circuit and control circuit wiring.

Clean the surface and interior of the circuit breaker, apply rust inhibitor (metal parts), and cover with a dust cover.

Remove easily aging components (such as rubber seals) and store them separately.

Storage environment: dry, ventilated, temperature -10~+30 ℃, avoid direct sunlight and humidity.

Pre activation check:

Remove the dust cover, clean the equipment, and inspect the components for rust and deformation.

Install the sealing ring and manually operate the closing/tripping mechanism more than 5 times.

Conduct insulation and functional tests, and only after passing the tests can it be put into use

Common troubleshooting (quick problem-solving)

Possible causes and solutions for fault phenomena

Unable to store energy 1. Interlock not unlocked (not in test/connection position); 2. The energy storage mechanism is stuck (due to foreign objects/insufficient lubrication); 3. Spring fatigue or fracture; 4. Fault in electric energy storage motor: 1. Switch to the test/connection position; 2. Clean up foreign objects and apply lubricating grease; 3. Replace the energy storage spring; 4. Check the motor power supply and winding, replace if there is a fault

Unable to close after energy storage 1. Trip mechanism not reset; 2. The closing interlock is not unlocked; 3. Fault in closing electromagnet (electric type); 4. Contact stuck. 1. Manually reset the trip mechanism; 2. Confirm that the circuit breaker is in the correct position and the padlock has been removed; 3. Check the power supply and winding of the electromagnet; 4. Clean the foreign objects on the contact and check the contact stroke

Immediately trip after closing: 1. Overload (load current exceeding the set value); 2. Short circuit fault (line/equipment short circuit); 3. The tripping parameter is set too small; 4. Grounding fault (I-A type); 5. Under voltage trip not reset. 1. Reduce the load and check the current; 2. Check the short circuit point, repair it, and then close it again; 3. Adjust the trip parameters (such as increasing the long delay current); 4. Check the grounding circuit and eliminate faults; 5. Reset the undervoltage trip device and check the control voltage

No indication after disconnection. 1. Trip indicator malfunction; 2. Power failure of the trip unit; 3. Mechanical indicator rod stuck. 1. Replace the trip indicator; 2. Check the power supply of the trip unit and tighten the wiring; 3. Clean up foreign objects on the indicator rod and apply lubricating grease

The release unit has no response. 1. Control power failure; 2. Loose wiring of the trip unit; 3. Sensor damage; 4. Fault in the trip unit: 1. Check the voltage of the control power supply; 2. Tighten the connection terminals of the release unit; 3. Test the sensor output signal and replace it if it is damaged; 4. Use a testing kit to detect the trip unit, and replace it if there is a malfunction