The ZIEHL MS220KA is a PTC thermistor relay designed to protect electrical equipment from overheating, particularly in environments with explosive gases (zones 1 and 2) and combustible dust (zones 21 and 22). It is suitable for direct temperature monitoring of explosion-proof motors classified under EEx e and EEx d standards. The relay continuously monitors the resistance of connected PTC thermistors and triggers an alarm or shutdown if the temperature exceeds predefined limits, ensuring the safety and longevity of the equipment.

Key Features:

• ATEX Compliance: Meets the ATEX directive 2014/34/EU for use in hazardous areas.

• Safety Integrity Level: Achieves SIL 1 according to IEC 61508 and Performance Level c (PL c) per ISO 13849.

• Short-Circuit Monitoring: Continuously checks the sensor circuit for short circuits, enhancing system reliability.

• Output Relay Options: Available with one or two change-over contacts (CO) for flexible integration into control systems.

• LED Indicators: Equipped with two LEDs to display operational status and alarm conditions.

• Compact Design: Features a 22.5 mm wide housing with vertically arranged terminals, facilitating easy installation on DIN rails or with M4 screws.

Technical Specifications:

• Supply Voltage Options: AC/DC 24 V or AC 220-240 V.

• PTC Thermistor Circuit: Supports a single set of 3 or 6 PTC sensors.

• Operating Temperature Range: -20°C to +55°C.

• Protection Rating: IP20 for terminals; IP30 for housing.

• Mounting: Suitable for DIN-rail mounting or screw mounting with M4 screws.

• Dimensions: 75 mm (H) x 22.5 mm (W) x 115 mm (D).

• Weight: Approximately 150 g.

Applications:

• Explosion-Protected Motors: Direct temperature monitoring to prevent overheating in motors used in hazardous areas.

• Industrial Equipment: Protection of transformers, machines, and other equipment against inadmissible heating.

• Hazardous Environments: Suitable for use in areas with explosive gases and combustible dust, ensuring compliance with safety standards.

ZIEHL - MS220KA - PTC Thermistor Relay for Explosion-Protected Equipment