1. Different wiring methods
The low-voltage voltmeter is directly connected to the circuit, and its range is generally 500V. The high-voltage voltmeter must be equipped with a voltage transformer, and the primary side voltage of the voltage transformer must be the same as the primary side voltage of the line under test, and the secondary side voltage is generally 100V.
2. The unit of voltage value is different
The low pressure meter reads V; the high pressure meter reads KV.
3. Different structure
The high voltage voltmeter has one more voltage transformer, and the voltage connected to the voltmeter is up to 100V, and the voltmeter is direct.
4. Different measurement methods
The low-voltage voltmeter can be directly connected to the circuit for measurement. The high-voltage voltmeter must be equipped with a voltage transformer with the transformation ratio marked on the meter to measure, and one phase must be grounded.