What are the common faults of motor vehicle accessories?

This is the most common fault for DC motor windings. Armature winding ground fault often occurs in the slot and the bottom of the tank, its determination can be used insulation resistance meter or check the lamp method, with an insulation resistance meter to measure the armature winding insulation resistance of the base, such as If the resistance is zero, the armature winding is grounded or the millivolt meter method shown in the figure is used. The 36V low voltage power supply is connected to the commutator chip and one end of the rotary shaft after passing through a low voltage lamp with a rated voltage of 36V. Light bulb, then the armature winding ground fault. Specifically, which bad winding element is grounded, it can be determined using the millivolt table method shown in the figure. Connect the two ends of the 6 ~ 12V low voltage DC power supply to the two commutator segments (K for the commutator segments) separated by K / 2 or K / 4, and then touch the motor shaft with a watch in the millivolt table. A watch is touched on the commutator, and the voltage between each commutator and the motor shaft is measured in turn. If there is a voltage value between the measured commutator and the motor shaft (ie, the millivolt meter has a reading), the winding element connected to the commutator is not grounded; conversely, if the reading is zero, The winding components of the wafers are grounded. Finally, it is also necessary to determine whether the winding element is grounded or connected to the commutator piece, and the end of the winding element should be removed from the commutator segments and tested separately.

This is also one of the common faults of DC motor motor accessories. Practical experience shows that the armature winding circuit breakpoint generally occurs in the winding of the winding element and the welding of the commutator. The reasons are: First, the welding quality is not good, the second is the motor overload, the current caused by excessive welding off. This breakpoint is generally easier to find, as long as careful observation of the commutator raised the film at the solder joint situation, and then screw the screw or tweezers toggle the welding point, you can find.

If the trip point occurs in the armature core slot, or difficult to find the site, you can use the method shown to determine. Connect the DC power supply from 6 to 12 V to the commutator segments K / 2 or K / 4 on the commutator and measure the voltage between the adjacent commutator segments with a pen plot and measure them step by step. The two commutator segments connected to the broken windings are read by the millivolt meter, with a reading indication and a sharp beating of the pointer. If the millivolt table crosses the two commutator segments connected to the perfect winding, the pointer will be indicated without a reading.