The insulation resistance of the generator should not be less than 0.5 MΩ.
Insulation resistance is the most basic insulation indicator for electrical equipment and electrical circuits. For transfer testing of low-voltage electrical equipment, the insulation resistance of motors, distribution equipment and distribution lines at normal temperature should not be less than 0.5MΩ (for equipment and lines in operation , the insulation resistance should not be less than 1 MΩ/kV).
As long as the insulation resistance of the generator rotor winding is not less than 0.5MΩ, it can be considered qualified.
The insulation resistance of the generator stator is not less than 1 MΩ per kV and can be considered qualified.
Detailed information:
Since insulation resistance is greatly affected by temperature, insulation resistance will decrease by half for every 10°C increase in temperature. Therefore, for ease of comparison, the insulation resistance at different temperatures is usually converted into a value. insulation at 75°C.
Factors affecting insulation resistance
1. Ambient temperature and humidity:
The insulation resistance value of general materials decreases with increasing ambient temperature and humidity. Relatively speaking, the surface resistance (rate) is more sensitiveble to ambient humidity, while volume resistance (rate) is more sensitive to temperature. Therefore, when measuring insulation resistance, it is necessary to specify the temperature and humidity at which the sample and the environment are in equilibrium.
2. Cable Specific Factors: When the cable is heated and wet, the insulation material ages. Its insulation resistance is reduced.
Baidu Encyclopedia Generator Test
Baidu Encyclopedia-Insulation Resistor
That's not what you said , both terminals are marked positive and negative. It is usually connected to the excitation output of the regulator, usually marked with F and N; the end of the power-producing wire should be thicker, usually marked with E, and is connected to the positive terminal of the battery if the P is. a 24V generator, check if it has a 12V output terminal.
All of the above can be yourtee with a multimeter. There should be tens of ohms of DC resistance between the two points of the excitation coil, and there should be forward and reverse resistance between the power generation output. end and the ground.
You can also refer to the wiring diagram in the generator manual for wiring.