WESTINGHOUSE Three Phase Induction Motors

Belt drive: The diameter of the pulley should meet the minimum recommended diameter of the motor (such as the minimum diameter of the V-pulley for a 45kW 4P motor ≥ 265mm), and the end face runout of the pulley after installation should be ≤ 0.1mm. The center distance of the pulley should be adjusted according to the length of the belt, and the tension of the belt should be moderate (press the midpoint of the belt, and the sinking amount should be 1%~2% of the length of the leather belt) to avoid slipping or excessive stress.

Electrical wiring:

Recheck the insulation resistance of the winding before wiring to ensure it meets the standard; Connect the wires according to the wiring diagram inside the motor junction box. The cross-section of the power cable should match the rated current (copper core cable ≥ 1.5mm ²/kW), and the wiring terminals should be tightly pressed to avoid virtual connection and heat generation.

The motor casing must be reliably grounded with a grounding resistance of ≤ 4 Ω; If the motor is a high-voltage model (6kV/10kV), it should be wired according to the high-voltage electrical regulations and equipped with insulation covers and warning signs.

Check the phase sequence to ensure that the motor direction is consistent with the equipment requirements (confirmed through jog testing, if the direction is opposite, swap any two-phase power supply wiring).

3. Debugging and trial operation

Pre startup inspection:

Mechanical inspection: Rotate the motor shaft again to confirm that there is no jamming; Check the tightness of the coupling bolts and pulleys, and ensure that the fan cover is securely installed; The oil level of the sliding bearing is at the center of the oil gauge, and the oil ring rotates smoothly.

Electrical inspection: The power supply voltage is stable (fluctuation ≤ ± 5%), and the protector parameters are set correctly (overload protection current 1.15 times rated current, trip time 1 hour); The wiring of auxiliary equipment such as heaters and temperature detectors is correct and working properly.

Auxiliary system inspection: The water inlet temperature of the water-cooled motor is controlled at 5-30 ℃, the water pressure is 0.2-0.4MPa, and there is no leakage; Start the cooling fan of the forced ventilation motor 15 minutes in advance to ensure normal heat dissipation.

Trial operation:

No load test run: Start the motor and run it without load for 30-60 minutes. Monitor the three-phase current (unbalance degree ≤± 5%), bearing temperature (≤ 70 ℃), vibration value (≤ 2.8mm/s), and ensure no abnormal noise, oil leakage, or burning smell.

Load test run: Gradually increase the load (by 20% of the rated load each time, stabilize for 30 minutes, and then increase again) until reaching the rated load, and continue running for 2-4 hours; Monitor winding temperature (≤ 105 ℃), bearing temperature (sliding bearings ≤ 90 ℃, rolling bearings ≤ 95 ℃), vibration value (≤ 3.8mm/s), and all parameters must be within the allowable range.

Debugging records: Detailed records of voltage, current, temperature, vibration and other data during the trial operation process, forming a debugging report as a reference for subsequent maintenance.

（4） Operation and Operating Standards

1. Key points for daily operation

Before starting the motor, it is necessary to confirm that the equipment load has been disconnected or is in a light load state to avoid heavy load starting; Observe the starting current during startup. If the startup time is too long (more than 10 seconds) or the starting current is abnormally high, immediately stop the machine for troubleshooting.

During operation, real-time monitoring of parameters such as three-phase current, voltage, winding temperature, bearing temperature, vibration value, etc. is carried out through the control cabinet display screen or on-site instruments. If any abnormalities are found (such as sudden increase in current, temperature exceeding the standard, and intensified vibration), the load should be immediately reduced or the machine should be stopped for inspection.

It is prohibited to disassemble fan covers, junction boxes, and other components while the motor is running. It is also forbidden to wipe the running motor with a damp cloth to avoid electric shock or burns.

After the motor stops, wait for the speed to completely drop to zero before performing load switching or maintenance operations; Frequent start stop is prohibited (in accordance with the frequency limit) to avoid overheating of the winding.

2. Handling of special working conditions

When the voltage fluctuation of the power grid exceeds ± 10%, it is necessary to reduce the load in a timely manner to avoid motor overheating; If the voltage continues to be abnormal, stop the machine and wait for the power grid to return to normal.

When the ambient temperature exceeds 40 ℃, the load should be reduced (by 10% for every 5 ℃ increase), and ventilation and heat dissipation should be strengthened; When the ambient temperature is below -20 ℃, the motor needs to be preheated (heated by a heater for 30-60 minutes) before starting to avoid lubricating oil solidification.