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

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

The TRM-300 digital overcurrent relays were developed to protect loads from damage caused by high currents while also enabling monitoring of operation.

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

Use of the device and operating principle

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

When switching on the device:
- The relay engages, 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 down the delay time and the ERR indicator lights up.
- After 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 used to automatically shut off devices when the maximum permissible current is exceeded.
It features a programmable trigger range, the ability to set the trigger time and the return time.
There are 3 programs for returning 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. The corresponding LED will light up in this mode.
- Semi-automatic mode: After an overcurrent fault, the system automatically resets three times and then waits for a manual reset upon the next fault. The LED indicator illuminates in this mode.
- Automatic mode: The system resets automatically after each overcurrent fault. The LED indicator lights up in this mode.

Note: To change the mode, press and hold the SELECT button for 10 seconds. The corresponding LED will light up when the mode has changed.

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 damage to the system in the event of a single-phase failure during engine operation).

During an asymmetry error:
- The indicator group of the two phases that caused the fault flashes and the ERR indicator lights up.
- To return from asymmetry error mode, the device must be manually reset.

Technical parameters:

- Operating voltage: 150-260 VAC.
- Operating frequency: 50/60 Hz
- Power consumption: < 6 VA
- Operating temperature: -20 °C to +55 °C
- Display: 3x3 digits, 5 LEDs
- Overcurrent setting (A>): 190-300 A
- Delay time: 1-200 s
- Connection type: Terminal block
- Contacts: 5 A / 250 V AC (active load)
- Wire diameter: 2.5 mm²
- Weight: max. 250 g
- Mounting: on DIN rail
- Operating altitude: < 2000 m

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

Basics