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

Load monitoring/limiting relay, 3-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 operational monitoring.

• 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 receive a ready-to-use device - current transformers are included.

Device usage and operating principle

1. Connect the device according to the attached electrical diagram.
2. When the wiring is ready, connect the power supply. After switching on, the set values are displayed on the screen for 5 seconds.
3. Use the "A>" regulator to set the overload value. The set value is displayed on the left screen.
4. Use the "t" regulator to set the delay time. The set value is also displayed on the left screen.

When the device is switched on:

• The relay switches on, 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 the delay time back and the ERR indicator lights up.
• When the time elapses, the relay switches off, the contact switches to terminal 1, and the OUT indicator goes off.

The TRM-50 series electronic current relay is designed for automatic disconnection of consumers when the maximum allowed current is exceeded. It features programmable switching range, switching time, and return settings. There are 3 "operating state" return modes - MANUAL, SEMI-AUTO, AUTO.

Return modes

• Manual mode: To reset the device after an overload, press the Reset button. The corresponding LED lights up.
• Pool automatic mode: Allows the device to automatically reset the system three times in case of overload and then waits for manual reset upon the next fault. The corresponding LED lights up.
• Automatic mode: The device allows the system to automatically reset every time an overload fault occurs. The corresponding LED lights up.

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

Current asymmetry 50% (fixed)

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

If an asymmetry fault occurs:

• The group of readings from the two phases causing the fault flashes and the ERR indicator lights up.
• Manual reset is required to exit asymmetry fault mode.

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: clamp connection
• Contacts: 5 A / 250 V AC (active load)
• Cable diameter: 2.5 mm²
• Weight: max. 250 g
• Installation: DIN rail
• Maximum altitude: <2000 m

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

Basic