Digital overcurrent relay with surge protection TRM-30M

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 overcurrent, overvoltage, and undervoltage. The current limit and time delay can be precisely set, and the measured voltage and current values are displayed 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 fault delay: 2 s (fixed value)
• Voltage fault reset: 2 s (fixed value)

Application and operating principle

Connect the device according to the enclosed wiring diagram. Incorrect connection can cause damage to the device. Set the overcurrent value according to the operating current values of the equipment you will use.

After you have connected the power supply:

• The set overcurrent value appears on the upper display within the first second.
• The fault delay time appears on the lower display.
• The voltage between phase L and neutral conductor N is displayed on the top display.
• The current drawn from the mains is displayed on the bottom display after one second.

Settings

• A> - setting the overcurrent value; the value is shown on the top display.
• sec. - Setting the wait time before the overcurrent fault condition is activated; the value is shown on the bottom display.

When the current is connected, the NO contact is closed and the "OUT" indicator lights up.

When the device enters a fault condition:

• The corresponding display blinks
• The LED "OUT" goes off.
• NO contact opens
• NC contact switches on

Protection functions

1. High current protection - transition to fault status:

• If the current drawn from the mains exceeds the set overcurrent value, the device waits for the set delay time and then switches to the fault status.
• Fault status: NO contact open, bottom display blinking, LED "OUT" off, NC contact closed.

Exit fault status:

• If the current drops below the set value, the device leaves the fault status after the reset button is pressed for 3 seconds.
• In normal operation: NO contact closed, bottom display steady, LED "OUT" on, NC contact open.

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

• When the voltage is higher than 250 V, the device waits 2 seconds and then switches to a fault status.
• Fault status: NO contact open, top display blinking, LED "OUT" off, NC contact closed.

Output:

• Device automatically leaves the fault status 2 seconds after the voltage has dropped below 245 V.
• Normal operation: NO closed, upper display remains lit, LED "OUT" lit, NC contact open.

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

• When the voltage is below 150 V, the device waits 2 seconds and switches to a fault status.
• Fault status: NO open, upper display blinks, LED "OUT" off, NC closed.

Output:

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

Fault indication

• Upper display blinks: on high or low voltage fault.
• Lower display blinks: on high current fault.
• LED "OUT": lights up when the device is in normal condition. NO contact closed.

Device status