Digital overcurrent relay with 3×3-digit LED display TRM-300

Three-phase current relay for load current control/limitation in the range of 190-300 A, manufacturer TENSE (Turkey)

Digital overcurrent relays TRM-300 are designed to protect loads from damage caused by high currents while allowing operation monitoring.

- 190-300 A (adjustable overcurrent value)
- 50% fixed current asymmetry
- Adjustable fault delay time
- Adjustable operating mode (automatic, semi-automatic, manual)
- When purchasing a TENSE brand current relay, you receive a ready-to-use device - including current transformers.

Device usage and operating principle

1. Connect the device according to the electrical diagram.
2. When the wiring is ready, connect the device to the power supply. After switching on, the set values are displayed on the screen for 5 seconds.
3. Use the "A>" regulator to set the overcurrent value. The set value is displayed on the left screen.
4. Use the "t" regulator to set the delay time. The set value is also displayed on the left screen.

When the device is switched on:
- The relay switches on, the output contact switches to terminal 3, and the OUT indicator lights up.
- When the current exceeds the set overcurrent value (A>), the device starts counting the delay time and the ERR indicator lights up.
- When the time has elapsed, the relay switches off, the contact switches to terminal 1, and the OUT indicator goes off.

The TRM-300 series electronic current relay is designed for automatic shutdown of devices when the maximum allowable current is exceeded.
It has a programmable switching range, the ability to set switching time and return time.
There are 3 programs to return to "Operating mode" - MANUAL, SEMI-AUTOMATIC, AUTOMATIC.

Return modes:

- Manual mode: After an overcurrent trip, the device must be reset by pressing the Reset button. The corresponding LED lights up in this mode.
- Semi-automatic mode: The system resets automatically three times after an overcurrent fault, then waits for manual reset on the next fault. The LED indicator is lit in this mode.
- Automatic mode: The system resets automatically after each overcurrent fault. The LED indicator is lit in this mode.

Note: To change the mode, hold the SELECT button for 10 seconds. The corresponding LED lights up when the mode changes.

Asymmetry 50% (fixed)

If the difference between the highest and lowest phase current exceeds 50%, the device enters asymmetry fault mode within 2 seconds.
(This prevents system damage in case of a single phase failure during motor operation).

During asymmetry fault:
- The indicator group of the two faulted phases flashes and the ERR indicator lights up.
- To exit asymmetry fault mode, the device must be reset manually.

Technical parameters:

- Operating voltage: 150-260 VAC.
- Operating frequency: 50/60 Hz
- Power consumption: < 6 VA
- Operating temperature: -20 °C to +55 °C
- Display: 3×3 digits, 5 LEDs
- Overcurrent setting (A>): 190-300 A
- Delay time: 1-200 s
- Connection type: clamp connection
- Contacts: 5 A / 250 V AC (active load)
- Wire diameter: 2.5 mm²
- Weight: max. 250 g
- Installation: DIN rail
- Operating altitude: < 2000 m

Note: Models TRM-50, TRM-100, TRM-200, and TRM-300 can only be used with the current transformers supplied with the device.

Basic