Digital overcurrent relay with overvoltage protection TRM-30M

TRM-30M current and voltage monitoring relay with display, single-phase up to 30 A

Single-phase digital relay designed to protect sensitive equipment from overcurrents, overvoltages, and undervoltages. It allows precise setting of the current limit and delay and displays the measured voltage and current values on a two-line display.

The TRM-30M is designed to protect single-phase equipment sensitive to operating current and voltage values. The relay includes a current transformer in the package and has the following functions:

• Overcurrent protection (adjustable current value 0.5 ... 30 A)
• Overvoltage protection, voltage above 250 VAC (fixed value)
• Undervoltage protection, voltage below 150 VAC (fixed value)
• Voltage hysteresis: 5 V (fixed value)
• Voltage error delay: 2 s (fixed value)
• Voltage error reset: 2 s (fixed value)

Application and operating principle

Connect the device according to the attached wiring diagram. Incorrect wiring can cause damage to the device. Set the overcurrent value based on the operating current values of the equipment you intend to use.

After connecting the power supply:

• The set overcurrent value is displayed on the upper display within the first second.
• The lower display shows the error delay time.
• The voltage between phase L and neutral conductor N is displayed on the upper display.
• The current drawn from the network is displayed on the lower display after one second of operation.

Settings

• A> - setting the overcurrent value; the value is displayed on the upper display.
• sec. - Setting the wait time before entering the overcurrent fault condition; the value is displayed on the lower display.

When power is connected, the NO contact is closed and the "OUT" indicator is on.

When the device enters an error state:

• The corresponding display flashes
• The "OUT" LED turns off.
• The NO contact opens
• The NC contact activates

Protection functions

1. High current protection - transition to fault state:

• If the current drawn from the network exceeds the set overcurrent value, the device waits the set delay time and then enters the error state.
• Error state: NO contact open, lower display flashing, "OUT" LED off, NC contact closed.

Exit from error state:

• If the current falls below the set value, the device exits the error state after pressing the reset button for 3 seconds.
• In normal operation: NO contact closed, lower display steady, "OUT" LED on, NC contact open.

2. Overvoltage protection (U > 250 V) - input:

• When the voltage is above 250 V, the device waits 2 seconds and enters an error state.
• Error state: NO contact open, upper display flashing, "OUT" LED off, NC contact closed.

Output:

• The device automatically exits the error state 2 seconds after voltage falls below 245 V.
• Normal operation: NO closed, upper display steady, LED "OUT" on, NC contact open.

3. Undervoltage protection (U < 150 V) - input:

• When voltage is below 150 V, the device waits 2 seconds and enters an error state.
• Error state: NO open, upper display flashing, LED "OUT" off, NC closed.

Output:

• Automatic termination of error state 2 seconds after voltage rises above 155 V.
• Normal operation: NO closed, upper display steady, LED "OUT" on, NC open.

Error indication

• Upper display flashes: in case of high or low voltage error.
• Lower display flashes: in case of high current error.
• LED OUT: lights up when the device is in normal status. NO contact closed.

Device status