TRM-30M Digital Overcurrent Relay with Surge Protection

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

Single-phase digital relay designed to protect sensitive equipment against overcurrents, overvoltages, and undervoltages. It allows precise adjustment of the current limit and timing and displays the measured voltage and current values on a two-line screen.

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 from 0.5 to 30 A)
• Over-voltage protection, voltage above 250 VAC (fixed value)
• Under-voltage 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. An incorrect connection may damage the device. Set the overcurrent value according to the operating current values of the equipment you will use.

After connecting the power supply:

• The set overcurrent value appears on the upper screen in the first second.
• The set overcurrent value appears on the upper screen during the first second.
• The voltage between phase L and neutral conductor N is displayed on the upper screen.
• The current drawn from the network is displayed on the lower screen after one second of operation.

Adjustments

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

When the device is powered on, the NO contact is closed and the "OUT" indicator is on.

When the device enters an error state:

• The corresponding display flashes
• The "OUT" indicator turns off.
• The NO contact opens
• The NF contact engages

Protection functions

1. protection against high currents - entering fault state:

• If the current drawn from the network exceeds the set overcurrent value, the device waits for the set delay duration and then enters an 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. Surge protection (U > 250 V) - input:

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

Output:

• The device automatically exits error state 2 seconds after the voltage drops below 245 V.
• Normal operation: NO closed, fixed upper display, LED 'OUT' lit, NC contact open.

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

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

Output:

• Automatic end of error state 2 seconds after the voltage exceeds 155 V.
• Normal operation: NO closed, fixed upper display, LED 'OUT' lit, NC open.

Error indication

• The upper screen flashes: in case of high or low voltage error.
• The lower screen flashes: in case of high current error.
• LED OUT: lights up when the device is in normal state. NO contact closed.

Device status