The MCHD protection relay for hermetically sealed, liquid-filled transformers or regulators according to EN 50216-3 for indoors and outdoors provides absolute confidence in the event of a fault in the hermetic profile. Each hermetic protection relay MCHD is individually tested for tightness and proper operation during component testing.

Functions of the hermetic protection unit MCHD

Oil level: As the oil level drops, the float moves down and switches a Reed switch. In addition, the oil level is visualized in the sight glass.
Temperature: The oil temperature is transferred to the temperature scale by means of a bimetallic thermometer with a display range of 0° C – 140° C. In addition, there is a protective relay MCHD as well as an adjustable limit switch and an indicator (Schleppzeiger) that can be reactivated.
Gas formation: When gas is collected (max. 170 cm3), it drives the float away and opens a Reed switch. In addition, the gas collection can be visually monitored through the observation glass.Oct.
Overpressure: In case of overpressure, the Viton membrane detects it and turns off the transformer. The value is adjusted in 5 kPa increments between 10 – 50 kPa.Dec.

Your advantages at a glance

– Reed switch for gas outlet and oil level
– Adjustable pressure switch
– Bimetal thermometer for measuring and monitoring oil temperature
– 1/8 Globe valve for oil sampling and ventilation
– UV resistant C5-M coating (SOLIDLINE)
– Float chamber separated from the switching mechanism
The Transformer Protection Relay MCHD is designed as an “all-in-one” protection device.Dec. It is a device that detects the most important hazards and issues an alarm signal according to needs or turns off the transformer reliably. Hermetic protective relay MCHD guarantees the hermetic protection of your transformers.

For detailed information, please download the brochure of hermetic transformer protection relay MCHD.