Direct digital overcurrent relay with 3×3 digit LED display TRM-25

Direct digital load relay with 3×3 digit LED display, three-phase with timer, range 0.1-25 A, manufacturer TENSE (Turkey)

Digital thermal relays are designed to prevent and control damage to loads caused by high currents.

- 0.1-25 A (adjustable overcurrent value)
- Fixed current asymmetry of 50%
- Adjustable error delay time
- Operating mode: adjustable (automatic, semi-automatic, manual)
- Internal current transformers

Device application and operating principle

Connect the device according to the wiring diagram. Once the connection is complete, apply power. After power-on, the display shows the set values for 5 seconds.

- Use the "A>" regulator to set the overcurrent value . The set value is displayed on the left display.
- Use the "t" regulator to set the delay time . The set value is also displayed on the left display.

When the device is energized, the relay energizes, 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. At the end of the time, the relay de-energizes, the contact switches to terminal 1, and the OUT indicator turns off.

The electronic current relay of the TRM-12 series is designed to automatically disconnect devices when the maximum allowed current is exceeded, with programmable intervention range, intervention time, and return time.
There are also 3 return-to-operational-state modes: MANUAL, SEMIAUTOMATIC, AUTOMATIC.

Reset mode:

- Manual mode: After an overcurrent fault, the device must be reset by pressing the reset button. In this mode, the corresponding LED is on.
- Semi-automatic mode: The device automatically resets the system three times when an overcurrent error occurs, then waits for a manual reset when another error occurs. In this mode, the corresponding LED flashes.
- Automatic mode: The device automatically resets the system every time an overcurrent error occurs. In this mode, the corresponding LED flashes.

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

Asymmetry 50% (fixed)

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

During an asymmetry error:
- The display group of the two phases that caused the fault flashes and the ERR indicator lights up.
- If the current is below 2 A, the device does not monitor asymmetry.
- To exit 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: from -20 °C to +55 °C
- Display: 3×3 digits, 5 LEDs
- Overcurrent setting (A>): 0.1-25 A
- Delay time: 0.1-20 s
- Connection type: terminal connection
- 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: TRM-50, TRM-100, TRM-200 and TRM-300 can only be used with the supplied current transformers.

The TRM-400 can be used with the 400/5 current transformer supplied with the TRM-400.

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