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

Three-phase current relay for load current monitoring/limiting in range 190–300 A, manufacturer TENSE (Turkey)

Digital overcurrent relays TRM-300 are designed to protect loads from protection against damage caused by high currents while allowing 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 get a device ready for ready for immediate use — current transformers are included.

Device use and operating principle

1. Connect the device according to the wiring diagram.
2. After completing the wiring, apply power. After at power-up, the display shows the set values for 5 seconds.
3. To set the value for overcurrent, use the "A>" controller. The set value is shown on left display.
4. To set the delay time use the "t" controller. The set value is also shown on the left display.

When the device is turned on:
• The relay switches on, the output contact switches to terminal 3, and the OUT indicator.
• If the current exceeds the set overcurrent value (A>), the device will counts down the delay time and the ERR indicator lights up.
• After the time elapses, the relay switches off, the contact switches to terminal 1, and the OUT indicator turns off.

TRM-300 Series Electronic Current Relay is designed for automatic disconnection of appliances when the maximum allowable current.
It has a programmable switching range, with options to set switching time and reclosing.
There are 3 return-to-"operational" mode programs available — MANUAL, SEMI-AUTOMATIC, AUTOMATIC.

Reset Modes:

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

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

Asymmetry 50% (fixed)

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

In case of asymmetry error:
• The display group of the two phases causing the fault starts blinking and the ERR indicator lights up.
• To return from asymmetry error 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: -20 °C to +55 °C
• Display: 3×3 digits, 5 LEDs
• Overcurrent setting (A>): 190–300 A
• Delay time: 1–200 s
• Connection type: terminal connection
• Contacts: 5 A / 250 V AC (active load)
• Conductor 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 models can only be used with current transformers supplied with the device.

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