ACS37800KMACTR-030B3-I2C Power Monitor - power parameters monitor with isolated I2C 240Vrms circuit (soldered connectors)

Description

The ACS37800KMACTR-030B3-I2C Power Monitor module is an advanced measurement board based on an Allegro Microsystems IC, designed for monitoring voltage, current, power, and other parameters in AC and DC systems. The device supports bidirectional current measurement from −30 A to +30 A and voltage measurement configuration up to 480 VRMS (±980 V peak). With galvanic isolation of the measurement path and secondary isolation of the I²C interface, the module ensures high measurement accuracy and user safety.

The sensor provides RMS and instantaneous readings, automatically detects zero crossings, and calculates active, reactive, and apparent power, as well as power factor. With a 1 kHz bandwidth, it is suitable for various energy and industrial applications. The integrated Hall-effect current sensor offers an isolated current path, low conduction resistance (0.85 mΩ), and high common-mode noise immunity. The board includes a resistor network optimized for 120 VAC, 240 VAC, and 480 VAC operation, enabling adaptation to a wide range of applications.

The communication interface is I²C, accessible via JST SH 4-pin connectors (compatible with Qwiic and STEMMA QT) or standard 2.54 mm pins. Configuration settings are stored in EEPROM, allowing customization of parameters such as device address and overload detection thresholds. The default I²C address is 0x60. Logic is powered by 3 V to 5.5 V, and the built-in isolated DC-DC converter powers the sensor circuit with 3.3 V.

The ACS37800 sensor measures current flowing from IP+ to IP−, which are clearly marked on the board along with a +i arrow indicating the positive current direction. Voltage is measured between IP+ and V− points on the left side of the board, with positive readings corresponding to higher voltage on IP+. For convenience, all through-holes on the left side are electrically connected, allowing power to be connected internally and load externally.

The board has two surface-mount jumpers that allow configuration of one of three voltage measurement ranges for the ACS37800 sensor. These ranges are optimized for 120 V, 240 V, and 480 VAC RMS. Each range supports overvoltage detection, handling transient voltages about 40% above the nominal peak voltage. This means the sensor can measure up to twice the nominal RMS voltage before reaching saturation, improving safety and accuracy under varying operating conditions. By default, one jumper is open, allowing measurement up to 240 VRMS.

The module also provides an EN input to disable logic power for energy savings. Multiple connection options are available: large 4 mm holes (for wires up to 10 AWG or ring terminals), screw terminal pads with 9.5–12 mm pitch, and smaller 2.54 mm and 5.08 mm pads for pin headers. The PCB includes isolation slots to increase creepage distance. This makes the module versatile and ideal for testing and implementing energy, industrial, and laboratory measurement solutions.

Features

• Current and voltage sensor based on ACS37800KMACTR-030B3-I2C
• Current measurement range: −30 A to +30 A
• Measures RMS and instantaneous current and voltage
• Calculates active, reactive, and apparent power and power factor
• Bandwidth: 1 kHz
• Automatic zero-crossing detection
• Hall-effect current sensor with isolated current path
• Low conduction resistance: 0.85 mΩ
• Supports single-phase AC and DC systems
• Configurable voltage ranges: 120 VAC, 240 VAC, 480 VAC (default jumper for 240 VRMS)
• Interface: I²C via JST SH 4-pin connectors or 0.1″ header pins
• Compatible with Qwiic and STEMMA QT
• Default I²C address: 0x60, configurable via EEPROM
• Programmable thresholds: overcurrent, undervoltage, overvoltage
• Logic power: 3 V to 5.5 V
• Integrated isolated DC-DC converter powering the sensor with 3.3 V
• Secondary I²C isolation for increased safety
• EN pin for power management
• Pre-soldered screw terminals
• PCB includes isolation slots for enhanced creepage distance
• Dimensions: 48.26 × 45.72 mm