Daily inspection and maintenance of motor electrical control system

The electric control system of the motor is composed of switches, small transformers, fuses, main and auxiliary contactors, relays, temperature, pressure sensing devices, etc., which are relatively complicated. There are many kinds of faults, and it is often necessary to use the control schematic analysis to check.

Usually pay attention to keep the inside and outside of the control box clean and dry, can not have water, oil, regularly use a small sweeper to blow clean the components inside the box and the binding posts, the dust on the row, or brush with a brush cleaning device, so as not to affect Contactor, relay work or insulation. There is a control box with a tidal resistance, and generally do not turn off the heating switch at will. The cabinet should also be grounded reliably to prevent electric shock.

Regularly check the wiring of the box and the tightening of the screws to prevent the wiring and screws from coming loose. Check whether the switch, contactor, relay and other components are damaged or ablated, and the working status of each component and the starting, stopping and interlocking functions are normal. It is necessary to keep the contactor moving and static contact sucking and good contact, and avoid burning out due to the lack of contact of the contact causing the motor to run out of phase. If the contact surface is good, only black, rub with a coarse cloth, do not easily polish the surface of the heat-resistant alloy layer, otherwise it will shorten the contact life; if the contact surface ablation is more serious, you can use the sand The paper smoothes it. Dynamic and static contacts need to maintain line contact or surface contact, not point contact. If the contact condition is good or bad, a paper strip can be placed between the moving and static contacts to check. If the clamping is not tight, the contact or spring needs to be adjusted or replaced. This point needs to be paid attention to. When it is light, a large contact resistance (current) will occur due to poor contact, which means that the load increases, causing the overload protection relay to trip, and the heavy motor will cause the motor to run out of phase and burn out. . One round is due to the lack of phase operation caused by the spring contact of the main contactor in the control box, and three oil separator motors are burned out within 10 months.

When replacing the relay contactor, you need to pay attention to the working voltage of the electromagnetic coil to avoid accidental burnout of the coil. Generally, there are 24V, 110V and 220V. For the time relay, in addition to paying attention to the coil voltage requirements, it is also necessary to clarify the time adjustment unit (hour, minute, second) and range of the time relay.

For a motor that is started by the star-delta (Y-â–³) method (conversion delay of about 5 seconds), it is necessary to check whether the conversion start condition is normal. Usually, the manufacturer has strict regulations on the starting cycle of the motor (ie, the number of starts per minute), and there will be a warning label on the starting control box to remind the user to prevent the motor from being damaged due to frequent starting, and also to prevent the starting control box. Some electrical components (such as starting reactors, etc.) inside are burnt and burned. Therefore, for the motor control system with frequent start or stop or large current, the inspection and maintenance cycle should be shortened. Such as: gram, anchor machine, winch machine, main engine auxiliary blower, main air compressor and boiler water pump, etc. should pay close attention to regularly check the protection function of the thermal overload relay (can be dialed next to the small red standard color system), The set action value should not exceed the rated current value of the motor nameplate to ensure overload protection.

In short, as long as the various machines and electric personnel strengthen their sense of responsibility, they will carry out regular inspections and maintenance as required, and when it is found that the sound, temperature rise, working current and insulation of the equipment are abnormal, they can be processed in time. Our electrical management The level will definitely reach a new level, adding a safety guarantee to the operation of the fleet.