Among the operating faults of three-phase asynchronous motors, the faults due to electrical connections account for a large proportion, and the fault points are often easy to find. To determine whether the electrical connection points are in good contact, the editor of Dalan Motor teaches you to use the following traditional methods:
(1) Visual inspection: check the connection points for discoloration, arc burns, breaks, etc.
(2) Hammering inspection: tap the connection point with a small hammer and listen for abnormal noise
(3) Feeler gauge inspection: measure the tightness of the two joint surfaces, if there is a gap, the contact is bad.
(4) Electrical inspection: Use a double-arm bridge to measure the DC resistance of the motor, and compare the records over the years (pay attention to the conversion to the same temperature). The difference between them is the poor contact.
(5) Tighten the bolts: re-tighten all electrical connection points, if there is looseness, it means poor contact.
The above methods have shortcomings and shortcomings, that is, they cannot accurately and intuitively reflect the poor contact of the electrical connection points. In the fourth type, the measurement accuracy is affected by the contact between the measurement line and the test point, and the oxidized contact of the bridge arm contact surface. In addition, the dual-arm bridge is powered by a battery and the current is small, which affects the measurement accuracy.
In addition, there are two better troubleshooting methods:
(1) Loop resistance tester measures the contact resistance of electrical connection points
The loop resistance tester uses a 220V AC power supply, which is composed of two parts: a measuring digital voltmeter and an adjustable constant current source. It can pass a large current of 100A for specific contact points, and the contact resistance value can be directly read by a digital meter. It can clearly and intuitively reflect whether the motor connection is in good contact.
(2) Use infrared thermometer to test the temperature of electrical connection point
Temperature is a very important factor in equipment fault diagnosis. Poor electrical connection often results in heat generation at the connection point. The connection point failure can be judged by temperature changes. The use of infrared thermometers can quickly provide temperature measurement, which is safe, accurate and does not require shutdown .
ï¼ï¼ï¼ï¼- Editor in charge: Dalan Oil Pump Motor 02-Procurement Consultant
All rights reserved http:/(Dalan Electric) Reprint please indicate the source
Fancy Usb Flash Drive,Pvc Usb Stick With Logo,Stock Usb Flash Drive,Usb Flash Drive Features,custom PVC USB flash drive
Shenzhen Konchang Electronic Technology Co.,Ltd , https://www.konchangs.com