DatasheetAdditional applications include monitoring the temperature of transformers, pumps, centrifuges, motor bearings, gearboxes, oil and coolants and the avoidance of thermal overload in the event of impeded cooling and high ambient temperatures.
The temperature is monitored directly at the winding using thermistors or bimetal switches. Up to 6 sensors can be connected in series. When a certain resistance is reached, the output relays switch off. Restarting takes place after cooling down via auto-reset.
The motor protection relay works with open circuit operation and also detects broken wire in the sensor circuit. The monitoring state is indicated by a yellow LED. The relay changeover-contact switches high power loads up to 6 A.
The Protective Separation and the 24 V DC power supply makes the DG 3802 universally applicable for all measurement and industrial applications, as well as for building automation.
Product line
| Device | Order No. |
|---|---|
| Thermistor Motor Protection Relay | DG 3802 |
Technical Data
Input
| Monitoring sensors | Thermistor/ PTC Resistor Sensor and Thermical Bimetal Switches (breakers, e.g. Klixon) |
|
| Monitoring function | Over-temperature protection in open circuit operation, restart via auto-reset |
|
| Number of sensors | 1 … 6 pcs | |
| Sensor load | ≤ 1 mA / 1 V / 1 mW | |
| Threshold value | ≥ 3 kΩ (relays drop out) | |
| Release value | ≤ 1.7 kΩ (relays pick up) | |
Output
| Contact type | 2 isolated changeover relays (SPDT), synchronous switching |
| Switching capability AC max. | 250 V / 6 A, 1500 VA |
| Switching capability DC max. | 250 V / 0.2 A, 115 V / 0.3 A, 30 V / 6 A |
| Recommended minimum load | 300 mW / 5 V / 5 mA |
| Status indication | yellow LED |
| Response time | < 50 ms |
General Data
| Switch error | < 5 % | |
| Temperature coefficient 1) | < 0.03 %/K | |
| Test voltage | 4 kV AC, 50 Hz, 1 min. input against power supply against both switching outputs 3 kV AC, 50 Hz, 1 min. switching output 1 against switching output 2 |
|
| Working voltage (Basic Insulation) 2) |
1000 V AC/DC for overvoltage category II and 600 V AC/DC for overvoltage category III according to DIN EN 61010 with pollution degree 2 between input, power supply and both switching outputs. Furthermore 300 V AC/DC between output 1 and output 2. | |
| Protection against electrical shock 2) | Protective separation according to DIN EN 61140 by reinforced insulation according to DIN EN 61010 up to 600 V AC/DC at overvoltage category II and 300 V AC/DC at overvoltage category III at pollution degree 2 between input, power supply and both switching outputs. Furthermore 300 V AC/DC between output 1 and output 2. |
|
| Power supply | 24 V DC, 15 %, approx. 0.7 W | |
| Ambient temperature | Operation Transport and storage |
–20 °C to +60 °C (-4 to +140 °F) –35 °C to +85 °C (-31 to +185 °F) |
| EMC 3) | EN 61326 -1 | |
| MTBF (acc. to EN 61709 / SN 29500) | 361.5 years (Tamb. 40 °C, FIT 315.5) | |
| Construction | 12.5 mm (0.5″) housing, protection class IP 20, mounting on 35 mm DIN rail acc. to EN 60715 | |
| Connection | Captive plus-minus clamp screws, Wire cross-section max. 2.5 mm² / AWG 14 Stripped length 6 … 8 mm / 0.28 in, Screw terminal torque 0.8 Nm / 7 lbf in |
|
| Weight | 70 g | |
- Average TC related to full scale value in specified operating temperature range, reference temperature 23 °C
- For applications with high working voltages, ensure there is sufficient spacing or isolation from neighboring devices and protection against electric shocks
- Minor deviations possible during interference
Block diagram
Dimensions
Terminal assignments
- 1.1 +Power supply +
- 1.2 −Power supply −
- 3.1Input
- 3.2Input
- Output 1
- 4.1COM
- 4.2NO
- 5.1NC
- Output 2
- 6.1COM
- 6.2NO
- 5.2NC
Do not connect terminal 2.1 and 2.2
