Encountered a problem: how to measure the bearing seat insulation after generator operation?. It is said that the bearing seat must be insulated, and the insulation is not good. What harm does it have? Expert guidance please. Thanks very much。
Two bearing housings, one is grounded, the other is insulated against the ground, the purpose is to avoid the shaft end voltage formation short circuit, short circuit current, and short circuit current will burn shaft, and bearing contact surface.The method of measuring the insulation of a bearing seat is to detect the voltage between the bearing housing and the ground,When the generator runs, the voltage is normal.
The landlord does not know whether this problem is the power of professional, I have seen two, do not know is you, why should the bearing insulation, when the generator is running, because the electromagnetic induction problem, will produce axial currents in large shaft, if between shaft and bushing formed circulation, there may be ablation the tile surface (or contact thrust head and shaft surface), so it should be insulated pad between shaft and bushing cut loop, which is why the insulation should be, but I think, if not the alloy tile, but fluoroplastic itself, has not added tile insulation, insulation pad, but due to installation problems in general, the unit with insulation pad, you ask what is in operation when the pad is insulation insulation detection device, I think it is not necessary, may not, because there are water guide bearing alloy tile (if it is ), we generally think of between the guide bearing and shaft is oil film, but if the guide bearing and shaft touch, insulation pad protects you, this may be the uncertainty of it, in addition to the protection of the electrical design requirements, not forced to set up to test the insulation pad insulation measurement device, the insulation is not can the long run? And I think there is a certain value on the line, such as 100M, is not a direct short circuit on the line, how to measure 500V, shake table, shake it, the other shaft grounding is not for you to test the bearing insulation, I know from the situation, to the general rotor one point grounding quasi the preparation of the large shaft grounding can not be measured, is, on the negative resistance, I do not know the answer if you are satisfied with the
The insulation of the bearing seat uses a measuring point of the meter to the bearing seat, and the other measuring point is facing the ground (mainly to test whether the insulating plate and the anchor bolt of the bottom of the bearing seat are correctly or damaged).The insulation of the bearing shell uses a measuring point of the meter to the bearing seat, and the other measuring point is opposite to the bearing shell (whether the insulation plate between the bearing plate and the bearing base is properly installed or damaged or not)- some units due to the lubricating oil used with insulating effect, so the insulating plate between bearing and bearing seat is not, in the process of installation without the oil car under the pump start, is unable to measure the insulation of the above two kinds, once again after turning measuring insulation is qualified.
