· Product Introduction

The SPM signal monitoring module is meticulously designed based on a new generation of embedded system. It is equipped with an isolated communication interface, enabling communication with a PC or PLC individually, or networking with multiple communication modules. The module also incorporates a transient suppression circuit, which effectively suppresses various surge pulses, ensuring reliable operation in harsh environments.

The SPM5-MB series DC insulation resistance monitoring module utilizes the unbalanced bridge principle to monitor the DC system voltage and the voltage from the DC positive/negative poles to ground in real-time. It features an RS485 communication interface, and data is acquired by the high-precision 16-bit ADC inside the module, with a measurement accuracy better than 0.5%. The power supply, input, and communication output are isolated from each other. When the insulation resistance of the bus to ground drops below the alarm setpoint, the relay triggers an alarm signal. It is widely used for monitoring ground insulation conditions in DC power systems.

This product requires an independent power supply and utilizes a standard 35mm DIN rail for mounting, offering simple installation and flexible use, adapting to a variety of field applications.

· Basic Parameters

Power Supply DC12～36V(DC24V recommended)

Power Consumption <3W

Measurement Accuracy ±0.5%F.S（+25℃）

Temperature Drift ≤500ppm/℃

ESD Protection ±15KV

Isolation Voltage 3000VDC

Dielectric Strength 1500VAC/1 minute (input, output)

Applicable Field Devices Configuration software, PLCs, touch screens, computers, and other devices supporting the MODBUS-RTU protocol

· Monitoring Terminal

Voltage Range DC10～100V or DC100～1000V

Number of Channels 1 Channels

Insulation Resistance Range 1KΩ～10MΩ

Monitoring Voltage DC220V/DC110V/DC48V/DC24V

Overvoltage Threshold ≥110% of rated voltage

Undervoltage Threshold ≤90% of rated voltage

Leakage Capacitance ≤5.0 μF

Monitoring Interval 1s～100s per cycle

Output Relay Drive capacity 5 A @ 250 VAC; 10 A @ 28 VDC

· Output Terminal

Output Signal RS-485 / ETH

Communication Protocol   Standard MODBUS-RTU protocol

Communication Distance 1200m (typical)

· Environmental Conditions

Operating Temperature -40℃～+80℃

Storage Temperature -40℃～+85℃

Relative Humidity 10%～90%RH (non-condensing)

Atmospheric Pressure 80kPa～106kPa