Fault Inspection for Blown Fuse When The Generator Set Start

Today, we will briefly introduce the problem of fault inspection of blown fuse or disconnected thermal relay when the generator set is started.

Troubleshooting steps. Check whether the fuse capacity of the generator set is appropriate, if it is too small, you can change it and try again. If the fuse continues to blow, check whether the drive belt is too tight or the load is too large, whether there is a short circuit in the circuit, and whether the motor itself is short circuited or grounded.

Ground fault checking method. Use a megohmmeter to measure the insulation resistance of the motor winding to ground. When the insulation resistance is lower than 0.2MΩ, it means that the winding is seriously damp and should be dried. If the resistance is zero or the calibration lamp is close to normal brightness, the phase is grounded. Winding grounding generally occurs at the outlet of the motor, the inlet hole of the power line or the winding extension slot. For the latter case, if it is found that the ground fault is not serious, the bamboo or insulating paper can be inserted between the stator core and the winding. After confirming that there is no grounding, it can be wrapped, painted with insulating paint and dried, and continue to be used after passing the inspection.

Inspection method for winding short-circuit fault. Use a megohmmeter or a multimeter to measure the insulation resistance between any two phases at the separate connecting lines. If it is even close to zero below 0.2Mf, it means that it is a short circuit between phases. Measure the currents of the three windings respectively, the phase with the largest current is the short-circuit phase, and the short-circuit detector can also be used to check the interphase and inter-turn short circuits of the windings.

Judgment method of stator winding head and tail. When repairing and checking the motor of the generator set, it is necessary to re-evaluate the head and tail of the stator winding of the motor when the outlet is disassembled and forgotten to be labeled or the original label is lost. Generally, the cutting residual magnetism inspection method, the induction inspection method, the diode indication method and the direct verification method of the change line can be used. The first several methods all require certain instruments, and the measurer must have certain practical experience. The direct verification rule of changing the thread head is relatively simple, and it is safe, reliable and intuitive. Use the ohm block of the multimeter to measure which two wire ends are one phase, and then arbitrarily mark the head and tail of the stator winding. The three heads (or three tails) of the marked numbers are connected to the circuit respectively, and the remaining three tails (or three heads) are connected together. Start the motor with no load. If the starting is very slow and the noise is very loud, it means that the head and tail of one phase winding are reversed. At this time, the power should be cut off immediately, the position of the connector of one of the phases should be reversed, and then the power should be turned on. If it is still the same, it means that the switching phase is not reversed. Reverse the head and tail of this phase, and switch the other two phases in turn in the same way until the starting sound of the motor is normal. This method is simple, but it should only be used on small and medium motors that allow direct starting. This method cannot be used for motors with large capacity that do not allow direct starting.

Starlight Power was founded in 1974 and is one of the earliest manufacturers of generators and diesel generator sets in China. If you want get more information, please feel free to send email to sales@dieselgeneratortech.com we will pay highly attention on your question.