Digital overcurrent relay with 3×3 digit LED display TRM-50

Load monitoring/limiting relay, three-phase, range 15-50 A, manufacturer TENSE (Turkey)

The TRM-50 digital overload relay is designed to protect loads from damage caused by high currents while allowing operation control.

• 15-50 A (adjustable overload value)
• 50% fixed current asymmetry
• Adjustable fault delay time
• Adjustable operating mode (automatic, semi-automatic, manual)
• When purchasing a TENSE current relay, you get a ready-to-use device - current transformers are included.

Device usage and operating principle

1. Connect the device according to the attached wiring diagram.
2. Once wiring is complete, connect the power supply. After powering on, the display shows the set values for 5 seconds.
3. Use the "A>" regulator to set the overload value. The set value is displayed on the left display.
4. Use the "t" regulator to set the delay time. The set value is also displayed on the left display.

When the device is on:

• The relay activates, the output contact switches to terminal 3, and the OUT indicator lights up.
• If the current exceeds the set overload value (A>), the device starts the delay countdown and the ERR indicator lights up.
• When the time expires, the relay trips, the contact switches to terminal 1, and the OUT indicator turns off.

The TRM-50 series electronic current relay is designed to automatically disconnect loads when maximum allowed currents are exceeded. It features a programmable intervention range, an intervention time, and intervention reversal settings. There are 3 modes to return to the "operational" state: MANUAL, SEMI-AUTO, AUTO.

Recovery mode

• Manual mode: To reset the device after an overload, press the reset button. The corresponding LED lights up.
• Semi-automatic mode: Allows the device to automatically reset the system three times when an overload occurs, then waits for a manual reset on the next error. The corresponding LED lights up.
• Automatic mode: The device allows the system to reset automatically whenever an overload error occurs. The corresponding LED lights up.

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

Current asymmetry 50% (fixed)

If the difference between the highest and lowest phase current exceeds 50%, the device enters asymmetry error mode within 2 seconds (prevents system damage in case of phase loss).

When an asymmetry error occurs:

• The display group of the two phases that caused the fault flashes and the ERR indicator lights up.
• To exit the asymmetry error mode, a manual reset is required.

Technical parameters

• Operating voltage: 150-260 VAC
• Operating frequency: 50/60 Hz
• Power consumption: <6 VA
• Operating temperature: -20 °C ... +55 °C
• Display: 3 × 3 digits, 5 LEDs
• Overload value (A>): 15-50 A
• Delay time: 0.1-20 s
• Connection type: terminal connection
• Contacts: 5 A / 250 V AC (active load)
• Cable diameter: 2.5 mm²
• Weight: max. 250 g
• Mounting: on DIN rail
• Maximum altitude: <2000 m

Note: TRM-50, TRM-100, TRM-200 and TRM-300 can only be used with the supplied current transformers.
TRM-400 can be used with a 400/5 current transformer.

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