The electromagnetic flowmeter is short-circuited. As a professional electromagnetic flowmeter manufacturer with technical expertise, after many years of careful and scientific research on the field application of commodities, it has concluded some problems that are easy to appear in the specific application of electromagnetic flowmeters. Next Xiaobian specifically analyzes the problem of the electromagnetic flowmeter failure caused by the fluid level, hoping to help the field application engineer solve the problem. The key to electromagnetic flowmeter failures that originate from the fluid level are the following:
The case is charged, the control circuit is out of control, and the winding is short-circuited and hot, which makes it unable to operate normally.
The damping of the winding reduces the insulation resistance; the motor is overloaded for a long time; the harmful gas is corroded; metal foreign matter invades the winding to damage the insulation; the insulation damages the core when the stator winding is re-wound; ; The insulation of the lead-out wire is in contact with the housing; the overvoltage (such as a lightning strike) causes the insulation to break down.
(1) Observation. Visually inspect the ends of the windings and the insulation inside the trunking to see if there are damage and black marks. If it is, it is the ground point.
(2) Inspection method. Use a multimeter to check the low resistance. If the reading is small, it is grounded.
(3) method. According to different levels, different megohmmeters are used to measure the insulation resistance of each group of resistances. If the reading is zero, it means that the winding is grounded, but the motor insulation is wet or breakdown due to accidents. It needs to be determined based on experience. Generally speaking, The pointer swings irregularly at "0", which can be considered as having a certain resistance value.
(4) Test the lamp method. If the test light is on, the winding is grounded. If spark or smoke is found somewhere, it is the winding ground fault. If the light is on, the insulation has ground breakdown. If the light does not turn on, but a spark appears when the test rod is grounded, it means that the winding has not broken down, but it is seriously wet. You can also use hardwood to tap on the edge of the shell of the shell. When you hit a certain place and wait for a while, it means that the current is on and off, and that place is the ground point.