The hermetic protection relay MHPR was developed together with transformer manufacturers and power suppliers. Its main task is to monitor the oil level in transformers, which are hermetically sealed. If the oil level in the filling pipe drops, a switching contact is activated. The MHPR protective relay is available in two lengths. We also offer additional gaskets on request.Oct.

Design of MHPR hermetic protective relay

The MHPR protective relay has replaced the pipe plug in the transformer filling pipe. The housing of the device is made of an aluminum alloy that is resistant to a pressure of up to 0.5 bar with a metal seal. The vertical movement of the float is transmitted to the switch. The float is made of an oil-resistant, closed porous material, thereby eliminating the risk of leaks in the float and ensuring a long-lasting buoyancy.

Your advantages at a glance

-Monitoring of oil level
– The reduced oil level opens the Reed contact
– Corrosion resistant materials
– 1/8 Globe valve for oil sampling and ventilation
Functional principle of MHPR protective relay
In a properly filled transformer, the float is in the highest position. If the oil level drops, the float moves down and turns on a button that triggers the alarm.