Thermistor protection relay (TPR)
5TT3
SIEMENS Low-Voltage Power Distribution
Overview
Thermistor motor protection relays monitor the thermistors wound in motors. This helps prevent thermal motor overloads, e.g. due to high switching frequency, single-phasing, disabled cooling or excessive ambient temperatures. Up to 6 thermistors in series can be monitored. A conductor break in the sensor conductor will immediately trip the device. The device can also be used for monitoring wound quick-break switches - e.g. bimetal thermostats. This offers all-round motor protection.
* For the detection of
- Temperature limits being exceeded
- Wire breaks in sensor circuits
* 1 input for 1 to 6 thermistors
* With 2 LEDs green/red for ready-to-run and fault
* Response value: 3.2 to 3.8 kΩ
* Release value: 1.5 to 1.8 kΩ
* Max. cable length of the sensor supply cable NYM 2 × 1.5 is 100 m
* Remote Reset: over A1/A2 (NC contact) or over X1/X2 (NO contact)
* LED displays:
- Green LED: lights up when operational voltage is applied
- Red LED: lights up in the event of overtemperatures or an interruption in the sensor circuit.
Benefits
* The test button for the diagnosis of the devices ensures high functional reliability for users.
* The ultra compact thermistor motor protection relay requires only the smallest of spaces. This saves costs.
* A remote reset enables the device to be switched back on again centrally at any time. This increases plant availability.
