Westinghouse DS/DSL series low-voltage power circuit breakers

Main circuit wiring: The tightening torque meets the requirements (copper bars/cables need to be crimped to the terminals) to avoid loosening and heating; The cross-sectional area of the three-phase wires is consistent, and the phase correspondence is correct.

Control circuit wiring: The electric operation type needs to be connected to a compliant control power supply (AC120/240V or DC48/125/250V), and the connection between the trip unit and the actuator should be firm with correct polarity (otherwise the protection function will fail).

Grounding requirements: The circuit breaker frame must be reliably grounded with a grounding resistance of ≤ 4 Ω to avoid electric shock caused by leakage.

3. Operation and operational safety

Working position operation:

Remove position: only used for maintenance or replacement. The energy storage spring must be released first, and all power sources must be disconnected. It is forbidden to remove it while it is still live.

Disconnect position: Both the main and auxiliary contacts are disconnected, which can be locked to prevent misoperation and is used for isolation and maintenance.

Test position (TEST): The auxiliary contact is connected, which can test the closing/tripping action and tripping function. The main circuit is not powered.

CONNECT: Normal operating position, it is necessary to confirm that the mechanical stop is in place, the interlocking device is locked, and it is prohibited to switch positions in the closed state.

Energy storage and closing operation:

Manual energy storage: DS-206 and other models require a single stroke downward pull on the energy storage handle, while DS-416 and above require multiple presses on the ratchet wheel. After energy storage is completed, there will be a "click" sound and the spring energy storage indicator light will light up.

Electric energy storage: After connecting to the control power supply, the circuit breaker will automatically store energy in the test/connection position. In case of energy storage failure, emergency manual energy storage can be used.

Closing taboos: Do not close with load; Do not repeatedly close the circuit when the short circuit fault has not been resolved; Do not close the circuit with current exceeding the nameplate.

Fault handling safety:

Troubleshooting after tripping: Overload tripping requires reducing the load, short-circuit tripping requires troubleshooting for line faults, grounding faults require checking the grounding circuit, and DSL series requires confirming whether the current limiting element is blown.

Emergency stop: In the event of a serious malfunction, emergency stop can be achieved through the panel trip button or remote trip signal, and forced locking and closing are prohibited.

4. Environment and Protection Safety

Operating environment: It is necessary to maintain dryness, cleanliness, good ventilation, avoid dust, oil mist, corrosive gases (such as chlorine and ammonia), and prevent contact oxidation and insulation aging.

Temperature control: When the ambient temperature exceeds 40 ℃, it is necessary to reduce the capacity (reduce the capacity by 10% for every 10 ℃ increase), and avoid direct sunlight or proximity to heat sources.

Moisture prevention measures: Insulation inspection should be strengthened in humid environments, and insulation resistance should be measured regularly (main circuit ≥ 1M Ω, control circuit ≥ 2M Ω).

Complete operation process (installation → debugging → maintenance)

1. Installation process (drawer style as an example)

Guide rail preparation: Open the circuit breaker cabinet door, unfold the built-in guide rail to a horizontal position, and ensure that the guide rail is not deformed or stuck.

Remove transportation fixing: Remove the transportation bracket and plastic protective cover on the circuit breaker, and check that the energy storage spring is not preloaded (released during transportation).

Push in the circuit breaker: Align the circuit breaker with the guide rail, slowly push it into the extraction position, insert the joystick and rotate it clockwise to switch to the disconnection position, test position, and connection position in sequence. Each position needs to be confirmed to be mechanically locked in place (with a "click" sound).

Wiring operation:

Main circuit: Connect the incoming and outgoing copper bars according to the phase, tighten the bolts (refer to the equipment manual for torque), and check the balance of the three-phase resistance.

Control circuit: Connect control power supply, remote closing/tripping signal, tripping unit power supply, check wiring diagram to avoid reverse polarity connection.

Grounding: Connect the grounding terminal of the circuit breaker frame reliably to the cabinet grounding bar.

Insulation test: Use a 500V megohmmeter to measure the insulation resistance of the main circuit. A resistance of ≥ 1M Ω is considered qualified, otherwise moisture or wiring faults need to be investigated.

2. Debugging process

Energy storage testing:

Manual energy storage: Operate the energy storage handle, confirm that the energy storage is completed, and the spring energy storage indicator light will turn on, and the closing mechanism can operate normally.