Digital overload 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)

TRM-300 digital overcurrent relays are designed to protect loads from damage caused by high currents, while providing operational 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 - current transformers are included in the set.

Device usage and operating principle

1. Connect the device according to the wiring diagram.
2. Once wiring is complete, connect the power. After switching on, the display will show the set values for 5 seconds.
3. Use the "A>" controller to set the overcurrent value. The set value is displayed on the left display.
4. Use the "t" controller to set the delay time. The set value is also displayed on the left display.

When the device is switched on:
- the relay switches on, the output contact switches to terminal 3 and the OUT indicator lights up.
- if 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 out.

The TRM-300 series electronic current relay is designed for automatic disconnection of devices if the maximum permissible current is exceeded.
It has a programmable trip range, the ability to set trip time and return time.
There are 3 programs to return to "operating" 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 indicator lights up.
- Semi-automatic mode: After an overcurrent fault, the system automatically resets three times, then waits for a manual reset for the next fault. In this mode, the LED indicator lights up.
- Automatic mode: The system automatically resets after each overcurrent error. In this mode, the corresponding LED indicator lights up.

Note: To change the mode, hold the SELECT button for 10 seconds. When the mode is changed, the corresponding LED indicator lights up.

Asymmetry 50% (fixed)

If the difference between the largest and smallest phase current exceeds 50%, the device enters asymmetry fault mode within 2 seconds.
(This prevents system damage if a single-phase fault occurs during motor operation.)

During asymmetry fault:
- At the moment when the group of both fault-causing phases flashes on the display and the ERR indicator lights up.
- To return from asymmetry fault mode, the device must be reset manually.

Technical parameters:

- Operating voltage: 150-260 V AC.
- Operating frequency: 50/60 Hz
- Power consumption: < 6 VA
- Operating temperature: from -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 (resistive load)
- Wire diameter: 2.5 mm²
- Weight: max. 250 g
- Installation: on DIN rail
- Operating altitude: < 2000 m

Note: TRM-50, TRM-100, TRM-200 and TRM-300 models can only be used with current transformers included in the device's package.

Basic