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 also allowing operational control.

• 15-50 A (adjustable overload value)
• 50% fixed current asymmetry
• Adjustable fault delay time
• Adjustable operating mode (automatic, semi-automatic, manual)
• When you buy 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 switching on, the set values will be displayed on the screen for 5 seconds.
3. Use the "A>" knob to set the overload value. The set value will be displayed on the left screen.
4. Use the "t" knob to set the delay time. The set value will also be 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 back the delay time and the ERR indicator lights up.
• Once the time has elapsed, the relay switches off, the contact switches to terminal 1 and the OUT indicator goes out.

The TRM-50 series electronic current relay is designed to automatically disconnect consumers when the maximum permissible current is exceeded. It has programmable switching range, switching time, and return settings. There are 3 modes for returning to "operating status" - MANUAL, SEMI-AUTO, AUTO.

Return modes

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

Note: To change the mode, hold down the SELECT button for 10 seconds. When the mode is changed, the corresponding LED will light up.

Current asymmetry 50% (fixed)

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

If an asymmetry error occurs:

• The group of readings for the two phases that caused the fault will flash and the ERR indicator will light up.
• A 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 a 400/5 current transformer.

Basic