Ptc Resistor Relay

April 22, 2018

Specially designed for internal motor monitoring. Ziehl ptc resistor relays are designed for ptc sensors according to din 44081 and din 44082.

Motor Thermal Protection Bimetallic Ptc Thermistors And

Ptc Thermistors

24vac Vdc Ziehl T221741 Ms220k Ptc Resistor Relay Business

Ptc sensors integrated in the motor windings directly measure the motor heat.

Ptc resistor relay. A ptc relay is a device that is used when the fridge compressor motor starts. A ptc thermistor is a thermally sensitive resistor whose resistance increases significantly with temperature. This direct temperature measurement enables the thermistor motor protection relays to evaluate various motor conditions such as overheating overload and insufficient cooling.

Ptc resistor sensors are suitable for the installation into windings of electrical machines bearings and transformers as well as to monitor the temperature of liquid media airflow and gases. Ptc resistor relays type ms ptc relay for the application as a protection device against inad missible heating up at electrical equipment in areas with explo sive gases zones 1 and 2 and areas with combustible dust 21 an 22 eg. Many electric motors and dry type power transformers incorporate ptc thermistors in their windings.

Thermistor motor protection relay k8ak ts pt monitor temperature rise through internal motor loss temperature phase sequence and phase loss monitoring with the din 225 mm sized k8ak pt relays. A fridge with a faulty ptc relay cannot start or continuously clicks on and off unable to start. The thermistor motor protection relay cm mss monitors the winding temperature and thus protects the motor from overheating overload and insufficient cooling in accordance to the product standard iec 60947 8 control units for built in thermal protection ptc for rotating electrical machines.

Therefor sensor and relays are exchangeable. Characteristics of ptc thermistors switching ptc thermistors are usually made of poly crystalline ceramic materials that are highly resistive in their original state and are made semi conductive by the addition of dopants. For direct temperatu re monitoring of explosion proof motors eex e and eex d.

In ptc relay the supply goes direct to the run winding but between supply and start winding a thermistor is connected in series and when we switch on the refrigerator the current start flowing through the thermistor to auxiliary and compressor start up this current flow heat thermistor and due to temperature the resistance of thermistor high and thermistor remove the start winding from supply. Ptc thermistor relay series pd 225 monitors and protects motors with integrated ptc resistor sensors protection against over heating for heavy duty load high switching frequency high operating temperature insufficient cooling conditions. When used in conjunction with a monitoring relay they provide overtemperature protection to prevent insulation damage.

Side by side mounting of k8ak pt relays. This compact version is espe. This instructable shows how to test a ptc relay to determine whether it is broken or not.