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

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

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

- 190-300 A (adjustable overcurrent value)
- Fixed current asymmetry of 50%
- Adjustable error delay time
- Adjustable operating mode (automatic, semi-automatic, manual)
- When you purchase a current relay from the TENSE brand, you receive a ready-to-use device - current transformers included.

Device use and operating principle

1. Connect the device according to the wiring diagram.
2. When wiring is complete, turn on the power. After powering on, the screen displays the set values for 5 seconds.
3. Use the "A>" controller to set the overcurrent value. The set value is displayed on the left screen.
4. Use the "t" controller to set the delay time. The set value is also displayed on the left screen.

When the device is powered on:
- The relay switches on, the output contact moves to terminal 3, and the OUT indicator lights up.
- If the current exceeds the set overcurrent value (A>), the device starts the countdown of the delay time and the ERR indicator lights up.
- After the time elapses, the relay switches off, the contact moves to terminal 1, and the OUT indicator turns off.

The TRM-300 series electronic current relay is designed to automatically disconnect devices when the maximum allowable current is exceeded.
It features a programmable trip interval, the ability to set the trip time and the return time.
There are 3 programs to return to "operational" mode - MANUAL, SEMI-AUTOMATIC, AUTOMATIC.

Reset modes:

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

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

Asymmetry 50% (fixed)

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

During an asymmetry error:
- The display group of the two phases that caused the fault will flash and the ERR indicator will light up.
- To return from asymmetry error 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
- Mounting: DIN rail
- Operating altitude: < 2000 m

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

Basic