• How to Use the Overload Capacity of Dry Type Transformers? The overload capability of dry type transformer The overload capacity of the dry type transformer is related to the ambient temperature, the load condition before the overload (initial load), the insu...
  • How to Maintain A Dry Type Transformer? Today's first-class dry-type transformer is primarily equipment that relies on air convection to cool. Therefore, it has good heat dissipation performance and excellent environmental applicability. Th...
  • Dry Type Transformer Cooling Method The dry mode of the dry type transformer is divided into natural air cooling (AN) and forced air cooling (AF). In the case of natural air cooling, the transformer can be operated continuously for a lo...

Transformer Megger Test

The megger has three terminal posts: one for "L", one for "E" and one for "G" (shield). L is connected to the wires, E is connected to the cable, and the "G" is attached to the insulated paper of the cable. The following points should be noted when measuring:

  • The power must be cut off first.
  • The megger must be kept flat when used.
  • Before we use the megger, we need to rotate several times to see whether the pointer is at the largest location. Then we will short-circuit the two terminals of "L" and "E", then slowly turn the hand of mega ohmmeter to see whether the pointer is at zero.
  • The megger cable must be insulated well, and the two lines shall not be twisted together.
  • When measuring the megger, the reading should be based on the number after a minute of rotation.
  • During the measurement, the number of meters should be transferred to 120 revolutions per minute.
  • The megger has a range of several thousand megaohm, with a minimum scale of about 1 trillion euro, which is not suitable for measuring the resistance below 100 kiloohm.