Digital Overcurrent Relay with 3×3-Digit LED Display TRM-50

Control/load limit relay, three-phase, 15-50 A range, TENSE (Turkey) manufacturer

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

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

Device use and operating principle

1. Connect the device according to the attached wiring diagram.
2. Once the wiring is complete, connect the power supply. After power-on, the display will show the set values for 5 seconds.
3. Adjust the overload value with the "A>" regulator. The adjusted value is shown on the left screen.
4. Adjust the delay time with the "t" regulator. The adjusted value is also shown on the left screen.

When connecting the device

• The relay turns 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 starts counting down the delay time and the ERR indicator lights up.
• Once the time has elapsed, 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 consumers when the maximum permissible currents are exceeded. It features a programmable trip range, trip time and inverse trip settings. There are 3 return-to-"operating" state modes - MANUAL, SEMI-AUTO, 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: Allows the device to automatically reset the system three times when an overload occurs, then waits for a manual reset on the next fault. The corresponding LED will light up.
• Automatic mode: The device allows the system to automatically reset each time an overload fault occurs. The corresponding LED will light up.

Note: To change the mode, press and hold 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 of the phases exceeds 50%, the device enters asymmetry fault mode in 2 seconds (prevents system damage when a phase is lost).

When an asymmetry fault occurs

• The display group of 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 LED
• Overload value (A>): 15-50 A
• Delay time: 0.1-20 s
• Connection type: clamp connection
• Contacts: 5 A / 250 VAC (active load)
• Cable diameter: 2.5 mm
• Weight: max. 250 g
• Mounting: on DIN rail
• Maximum altitude: <2000 m

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

Basic