A Metal Oxide Varistor (MOV) is a semiconducting 'clamping' device which, under normal operating conditions has a very high resistance, but when the voltage across the varistor exceeds its rated value, the varistor's resistance decreases, and enables any overvoltage to be safely diverted to earth. These are bipolar, non-linear resistors, with a symmetrical voltage/current characteristics curve and a resistance value which decreases as the voltage increases. Features include:
- High Energy and Current withstand capability.
- Low clamping Voltage
- Fast Response (typically 5 nanoseconds)
- Suitable for AC and DC applications
- Bipolar operation
- Very low leakage current
PD Devices Ltd is a leading designer and manufactuer of MOV, one of only a handful within Europe, producing Metal Oxide Varistors and MOV Assemblies for a wide range of industries and applications. A selection of our MOVs can be seen here, but if you cannot find the Metal Oxide Varistor or MOV asembly you require for your application, please contact our technical team..
European electrical AC voltages are classified in terms of Low Voltage = LV, Medium Voltage =MV and High Voltage = HV, and the International Electrotechnical Commission has classified the voltages into the following levels (IEC 60038).
| Voltage Level | Code | Voltage Rating |
|---|
| Low Voltage |
LV |
up to 1000V |
| Medium Voltage |
MV |
1000V to 35kV |
| High Voltage |
HV |
35kV to 230kV |
| Extra High Voltage |
– |
above 230kV |