Wuxi Lanhai Electric Motor Co.,Ltd
Add: 4#, Tianshi Road Shitangwan Town, Wuxi, Jiangsu, China
Reasons and Prevention of Single - phase Operation of Electric Motor
In the modern industrial production, the motor is widely used, but in the production of motor due to lack of operation caused by the burning of the accident in production accounted for a large proportion of how to reduce the emergence of these problems, improve the efficiency of the motor, A question worthy of serious consideration, according to my own years of practical work and relevant information, is proposed to prevent motor single-phase operation of the measures, for reference only, shortcomings, please give valuable advice.
First, the motor single-phase operation of the causes and preventive measures
1, fuse blown
⑴ fault fuse: mainly due to the motor main circuit single-phase ground or phase short circuit caused by fuse blown.
Preventive measures: select the motor to adapt to the surrounding environment and the correct installation of low-voltage electrical appliances and lines, and to be regularly checked to strengthen the daily maintenance work, the timely elimination of various risks.
⑵ non-fault fuse: the main choice of the melt capacity is not appropriate, the capacity is too small, when starting the motor, by the impact of starting current, fuse fuse.
Fuse non-fault fusing can be avoided, do not one-sided that can escape the motor starting current in the case of the capacity of the melt as much as possible to choose a smaller, so as to protect the motor. We have to make it clear that the fuse can only protect the motor single-phase ground and phase-to-phase short-circuit accident, it must not be used as motor overload protection.
2, the correct choice of the capacity of the melt
General melt rated current selection formula: rated current = K × motor rated current
⑴ heat capacity of the larger fuse (with filler type) K value can choose 1.5 to 2.5.
⑵ heat capacity of the smaller fuse K value can choose 4 to 6.
For the motor with the load is different, K value is also different, such as the motor directly to drive the fan, then the K value can be selected larger, such as the motor load is not large, K value can choose a little smaller, depending on the motor load To decide.
In addition, the fuse between the melt and the need to contact between the good, otherwise it will cause contact heat, so that the melt caused by external heat caused by non-fault fuse.
In the process of installing the motor, should use the appropriate wiring and the correct maintenance method.
⑴ for copper, aluminum connection as much as possible the use of copper and aluminum transition joints, such as no copper and aluminum joints, copper joints can be linked to tin.
⑵ for the larger capacity of the plug-in fuse, the wiring can be padded with thin copper (0.2mm), this effect will be better.
⑶ Check and adjust the contact pressure between the melt and the frit.
⑷ to avoid damage to the fuse when wiring, fastening to moderate, the wiring to be pad spring washers.
3, the main circuit is prone to failure
⑴ contactor of the static and dynamic contact bad.
The main reason is: improper contactor selection, contact the arc of the small, so that static and dynamic contact stick together, three-phase contact action is not synchronized, resulting in phase loss operation.
Precautions: Choose a more suitable contactor.
⑵ poor use of the environment such as moisture, vibration, corrosive gases and poor heat conditions, resulting in damage to the contact or wiring oxidation, poor contact caused by phase loss operation.
Precautions: Select the electrical components to meet the environmental requirements, protective measures should be appropriate to force the improvement of the surrounding environment, regular replacement of components.
⑶ from time to time inspection, contactor wear a serious contact, the surface uneven, so that contact pressure caused by lack of phase to run.
Precautions: According to the actual situation, to determine a reasonable inspection and maintenance cycle, strict and serious maintenance work.