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

Load monitoring/limiting relay, 3-phase, range 15-50 A, manufacturer TENSE (Türkiye)

The TRM-50 digital overload relay was developed to protect loads from damage caused by high currents while also enabling operational control.

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

Use of the device and its operation

1. Connect the device according to the enclosed wiring diagram.
2. After completing the wiring, connect the power supply. Once switched on, the display will show the set values ​​for 5 seconds.
3. Use the "A>" control to set the overload value. The set value is displayed in 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 the device is switched on:

• The relay engages, the output contact switches to terminal 3 and the OUT indicator lights up.
• If the current exceeds the set overload value (A>), the device counts down the delay time and the ERR indicator lights up.
• After the time expires, the relay triggers, the contact switches to terminal 1 and the OUT indicator goes out.

The TRM-50 series electronic current relay is designed to automatically disconnect loads when maximum permissible currents are exceeded. It features a programmable tripping range, tripping time, and tripping reversal settings. There are three modes for returning to operating mode: MANUAL, SEMI-AUTO, and AUTO.

Reset modes

• Manual mode: To reset the device after an overload, press the reset button. The corresponding LED will light up.
• Semi-automatic mode: This allows the device to automatically reset the system three times in case of an overload and then waits for a manual reset upon the next error. The corresponding LED will light up.
• Automatic mode: The device automatically resets the system in the event of any overload error. The corresponding LED will light up.

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.

Current asymmetry 50% (fixed)

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

If an asymmetry error occurs:

• The indicator group for the two phases that caused the fault is flashing and the ERR indicator is illuminated.
• 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 block
• 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: The TRM-50, TRM-100, TRM-200 and TRM-300 can only be used with the current transformers included in the scope of delivery.
The TRM-400 can be used with the included 400/5 current transformer.

Basics