Motor thermistor relay MTR02
MTR02 relay controls motor winding temperature. It is based on the measurement of PTC thermistor which is built in electrical motor. Device also controls short-circuit or probe disconnection. The relay has galvanically separated measuring inputs and one output double-throw contact 8 A.
- motor winding temperature monitoring
- short circuit monitoring and sensor disconnection
- galvanic insulated measuring inputs
- output relay contact 8 A
- universal power supply 89 ... 264 VAC
- one DIN rail module size
- optical status LED signalization
Function
If the motor temperature is under maximum limit (PTC = 3.3 kΩ), green LED is ON and contact 15-16 is closed. As soon as the motor winding is overheated (PTC > 3.3 kΩ), red LED turns ON and contact 15-18 switches ON. Switch OFF operation will occur after the motor winding temperature drops down (PTC 1.8 kΩ) and button RESET has been pressed. This feature protects motor against spontaneous start and it is possible to be disabled by cross connection of terminals T1, R1 (AUTORESET). There is also possibility to use terminals T1, R1 for external reset. If the PTC input is short-circuited, alarm appears and terminal 15-18 will switch ON.
Technical features
| Parameter | Value |
|---|---|
| supply voltage | 89 ... 264 VAC |
| self consumption | max. 1.5 VA |
| galvanic insulation of measuring terminals | ANO |
| thermistor resistance PTC operating state | 200 Ω ... 3.3 kΩ |
| thermistor resistance PTC alarm state | > 3.3 kΩ |
| condition of alarm status canceling | PTC < 1.8 kΩ + RESET |
| number and type of output contacts | 1 x changeover |
| nominal current | 8 A |
| switching power | max. AC 2000 VA |
| trigger current | 30 A |
| nominal/max switching voltage | 250 VAC / 440 VAC |
| mechanical lifetime | 3 x 107 |
| electrical lifetime | 1 x 105 250 VAC, 8 A |
| ambient temperature | -20 ... +55 °C |
| working position | any |
| mounting | IEC 60715 (DIN 35) |
| protection degree | IP 20 |
| electrical strength | 4 kV |
| maximum input wire diameter | max. 2 x 1.5 mm2; 1 x 2.5 mm2 |
| weight | 75 g |
| dimensions | 90 x 18 x 65 mm |
| related norms | IEC 60255-1 |