Device overview
The Huawei DTSU666-H 100A Smart Power Sensor is a three-phase, CT-operated meter used at the grid connection point of compatible FusionSolar installations. It reports household or site power flow to the inverter so the system can measure grid import and export, enforce export limits, and coordinate battery charging or discharging.
Core specifications
Huawei specifies three-phase three-wire and four-wire operation, a 304-499 V line-voltage range, and three supplied 100 A / 40 mA current transformers. The published measurement figures are ±0.5% for current and voltage, ±1% for power and energy, and ±0.01 Hz for frequency. Huawei markets the device as Class 1 measurement accuracy.
Installation
The meter mounts on a DIN35 rail inside a suitable electrical enclosure. Installation requires voltage wiring, correct phase mapping, correct CT orientation, and an RS-485 link to the compatible Huawei inverter or communication host. This is professional panel work; incorrect CT direction or phase assignment can reverse or distort the reported power flow.
Compatibility and communication
Communication is local RS-485 Modbus RTU at 9,600 bps. The official quick guide documents addresses 11-19 and requires the meter communication settings to match the inverter. Compatibility should be checked against the exact Huawei inverter model, firmware, country certification and current compatibility documentation before purchase.
Cloud and Home Assistant
The LCD and RS-485 measurement path do not require a vendor cloud. FusionSolar cloud remains useful for remote dashboards, history and fleet services. EnergyMeterHub does not mark native Home Assistant support because Home Assistant's official integration catalog does not list this exact meter; community Huawei inverter integrations should be evaluated separately.
Best-fit scenarios
This model is most useful in three-phase Huawei solar or storage systems that need grid import/export measurement, export limitation or battery energy-management feedback. The 100 A value is the supplied CT measurement range, not direct current through the meter terminals.
Strengths and limitations
Strengths include exact Huawei ecosystem positioning, separate import/export readings, an LCD, low stated power consumption and local Modbus communication. Key limitations are its inverter-oriented integration model, professional installation requirements, and the need to verify exact inverter compatibility and local distribution availability.
Purchase and official sources
Use Huawei's current DTSU666-H 100A product page, specification sheet and installation guide as the primary references. Confirm that the package contains the 100 A / 40 mA CT set rather than the older 250 A / 50 mA variant before ordering.