Digital overcurrent relay with voltage protection and 3×3 digit LED display TRM-30F

TRM-30F overcurrent monitoring relay with display, 3-phase up to 25A

It is designed to protect equipment sensitive to operating current and voltage values ​​from the following faults:

• current overload (adjustable current value 0.5 ... 30 A)
• current asymmetry (50%, fixed value)
• voltage asymmetry (30%, fixed value)
• overvoltage and undervoltage (Umin: 265 V, Umax: 440 V, fixed value)

The TRM-30F digital overcurrent overload relay with display allows you to view the current of each phase and protect your motor or equipment against overcurrent, overvoltage, undercurrent, phase loss and phase reversal. These digital overload relays are designed to prevent motor/load damage due to high currents while allowing you to monitor the current flowing in each phase on the display. They are also capable of monitoring the cumulative voltage values ​​between phases.

With two output relays (1x NO, 1x NC) it is also possible to control or disconnect the load when the overcurrent reaches a set value, or to switch on a signal contact to the control system. The TRM-xx digital relays have built-in current transformers and a 3x3 digit display for current indication.

Application and operating principle

1. Connect the device according to the wiring diagram. Incorrect connection may damage the device.
2. Set the device's overcurrent with the ">A" control according to the operating current of the load to be checked.
3. When the device is turned on, the upper display shows the set overcurrent value and the middle display shows the error waiting time within the first second.
4. The actual values ​​of the phase currents are displayed after one second and the indicator LED lights up.
5. When the "V/A/RESET" button is pressed, the combined voltage values ​​between phases are displayed.

Drives

• "A>" - setting the permissible overload; the value is displayed on the upper display.
• "sec." - setting of the overcurrent fault waiting time; the value is displayed on the central display.

Contact status

• NO 95-96, NC 97-98:

• The device is de-energized or in error state: NO open, NC closed.
• The device is energized and without error: NO open, NC open.

Indicator LED

• LED "V" - lights up in case of overvoltage/undervoltage or voltage asymmetry error.
• LED "A" - lights up in case of high current or current asymmetry error.
• "XI" LED - lights up if the phase sequence is incorrect.
• LED "NOR" - lights up when the device is powered and the system is fault-free.

Function of the "V/A/RESET" button

• Reset: Pressing for 3 seconds clears the error, LED "A" goes out, NO contact turns on, NC contact opens.
• V/A: by pressing briefly, the display switches between current and voltage values.

Protection and operating principle

1. Overcurrent protection (0.5-30 A):

• Entering fault state: when the set overcurrent is exceeded, the set time waits. The phase indicator flashes, LED "A" lights up, NO is open, NC is closed, LED NOR turns off.
• To exit error state: current below the set value, press the reset button for 3 seconds.

2. Protection against current asymmetry:

• Input: current difference between phases >50%, wait 3 seconds, display flashes, LED "A" lights up.
• Exit: difference <50%, press the reset button for 3 seconds.

3. Overvoltage protection (U>440 V):

• Input: voltage >440 V, wait 3 seconds, display flashes, LED "V" lights up.
• Exit: voltage <435 V for 3 seconds.

4. Undervoltage protection (U<265 V):

• Input: voltage <265 V, wait for 3 seconds, display flashes, LED "V" lights up.
• Exit: voltage >270 V for 3 seconds.

5. Protection against voltage asymmetry:

• Input: voltage difference >30%, wait 3 seconds, display flashes, LED "V" lights up.
• Abandonment: difference <30% for 3 seconds.

6. Phase sequence protection:

• In case of incorrect phase connection, LED "XI" lights up.

Calculation of current asymmetry

The device calculates the asymmetry according to the formula:

Example: ((25 - 15) / 25) × 100 = 40% current asymmetry.

Technical specifications

• Supply voltage: measured voltage 3ph 3x400 VAC
• Operating voltage (Un): 3x380 VAC 50/60 Hz, own power <10 VA
• Adjustable overcurrent (overload): 0.5-30 A
• Error waiting time (t): 0-20 s
• Display: 3x3 digits, 9 mm high, 7 display LEDs
• Overvoltage: 440 V (LL)
• Undervoltage: 265 V (LL)
• Voltage asymmetry: 30%
• Current asymmetry: 50%
• Waiting time in case of asymmetry error: 3 s
• 2x output relays (1x NO, 1x NC): 3 A / 250 V AC (resistive load)
• Connection type: screw terminals
• Cable cross-section: 2.5 mm² (relay contacts) / 6 mm² (input and output measurement loads)
• Weight: up to 380 g
• Mounting: DIN rail
• Operating temperature: -20°C ... +55°C
• Operating altitude: <2000 m