Huawei DTSU666-FE 100 A Smart Power Sensor
Huawei DTSU666-FE Smart Power Sensor, class 1, single-phase and three-phase up to 100 A, with 3 current transformers included. 35 mm DIN-rail mounting, Modbus-TCP communication.
It is the component that enables dynamic regulation and PV-preferred charging on Huawei Smart Chargers installed in systems without a Huawei inverter.
The Huawei DTSU666-FE is the Smart Power Sensor that measures the energy exchanged with the grid and passes the data to the Huawei system. It is a compact DIN-rail board meter, but its role is that of a control device: without this measurement the wallbox does not know what is happening in the home and cannot regulate itself.
When you need it and when you don't
This is the question that matters, and the answer is clear-cut: the DTSU666-FE is needed when a Huawei Smart Charger is installed in a system without a Huawei PV inverter. If the home already has a Huawei inverter, the production and consumption data comes from the inverter itself and this sensor is not required.
Put another way: anyone buying a Huawei wallbox for a home without PV, or with a system of another brand, must also budget for this component, otherwise the wallbox will work like a smart socket but lose the very functions it was chosen for.
What it actually enables
- Dynamic power regulation - the sensor measures in real time how much the building is drawing; the wallbox reduces charging current when the oven, induction hob or heat pump come on, avoiding a trip of the supply limiter.
- PV-preferred charging - by measuring the energy fed into the grid, the system recognises the available surplus and directs it to the car instead of exporting it.
- Consumption monitoring on FusionSolar - the data flows into the portal and app, where it becomes readable over time.
DTSU666-FE technical specifications
| Type | Smart Power Sensor for the Huawei EV Charger solution |
| Supported configurations | Single-phase and three-phase |
| Maximum current | 100 A |
| Accuracy class | Class 1 |
| Current transformers | 3 CTs included (100 A / 40 mA) |
| Communication | Modbus-TCP over Ethernet |
| Mounting | 35 mm DIN rail |
| Weight | 0.4 kg |
Frequently asked questions
I already have a Huawei inverter: do I still need to buy it?
No. In systems with a Huawei PV inverter the grid-exchange data is already available through the sensor associated with the inverter, and the wallbox uses it directly. The DTSU666-FE is for the opposite case, that is when the wallbox works without a Huawei inverter upstream.
Are the current transformers included?
Yes, the supply includes three 100 A CTs. They are the part clamped onto the line conductors to measure current: they must be installed respecting the indicated direction and phase, because a CT fitted the wrong way round produces readings with reversed sign and confuses the regulation.
Where is it installed?
In the main electrical board, on a 35 mm DIN rail, positioned to measure all the energy exchanged with the grid: downstream of the meter and upstream of the loads and the wallbox. The position is decisive, because a sensor installed in the wrong place measures only part of the consumption.
Is it fine for both single-phase and three-phase systems?
Yes, the DTSU666-FE supports both configurations up to 100 A, so it covers both the single-phase house and the three-phase supply paired with the SCharger-22KT-S0. Configuration is done during commissioning.
What is the difference from the DTSU666-H used with inverters?
They are sensors of the same family but for different purposes: the H version is the one paired with Huawei PV inverters, while the FE variant is dedicated to the EV Charger solution and communicates in Modbus-TCP over Ethernet. They are not interchangeable: always check the exact code required by the documentation of the product you are installing.
