The Sunsynk Wireless CT (SUNCT-RS03) is a LoRa-enabled current transformer clamp designed for the Sunsynk Acure inverter range. Traditional wired CT clamps must be cabled all the way back to the inverter — a route that can cross rooms, floors, and finished walls. The SUNCT-RS03 eliminates this entirely: clip the sensor around the incomer cable at your consumer unit, and it transmits grid import/export data wirelessly to the Acure over the inverter's built-in LoRa radio, tested to 200 metres. Up to two wireless CTs can be paired per Acure inverter. The result is a cleaner, faster installation — no CT cable routes to plan, no conduit, no surface trunking.
Acure
Compatible Range Only
⚠ Compatibility & Installation: The SUNCT-RS03 is only compatible with Sunsynk Acure series inverters (SunC1 and SunC2). It will not pair with other Sunsynk models. The CT clamp must be fitted on the live conductor of the grid incomer — the cable between the meter/cutout and the consumer unit. Directional arrow on the sensor must point toward the load (consumer unit) side. Never fit on neutral or earth conductors.
⚡ Zero-Export Use: For zero-export limiting, the CT must measure the grid incomer (not a sub-circuit). An incorrectly positioned CT will feed the inverter erroneous import/export values, causing incorrect throttling or unwanted grid export.
ℹ Installation Benefit: The SUNCT-RS03 is especially valuable where the inverter and consumer unit are in different locations — for example, a garage-mounted inverter with the house consumer unit in a hallway. No CT signal cable route is required between the two locations.
Key Features
LoRa Wireless Transmission
Uses the sub-GHz LoRa band built into every Acure inverter — the same radio as the Smartlynk switch. LoRa penetrates concrete floors and masonry walls far more effectively than Wi-Fi or Bluetooth, sustaining reliable readings in electrically noisy environments.
Bidirectional Grid Measurement
The CT measures bidirectional current on the grid incomer, giving the inverter real-time import and export data. This drives zero-export limiting, self-consumption optimisation, and accurate energy accounting in Sunsynk Connect Pro.
Faster, Cleaner Installations
Eliminating the CT signal cable saves significant installation time and avoids the need to route cable between meter position and inverter — particularly valuable in multi-storey or open-plan properties where chasing or surface trunking is unacceptable.
Up to Two CTs per Inverter
A single Acure supports two SUNCT-RS03 sensors simultaneously — useful where separate monitoring of an EV charge circuit or a sub-distribution board is required alongside the main incomer measurement.
Enables Zero-Export Control
Many DNOs and private landowners require zero export to the grid. The SUNCT-RS03 gives the Acure the real-time grid signal it needs to throttle inverter output and prevent any net export, satisfying G99 conditions where export is not permitted.
Pairs via Acure Touchscreen
Registration is performed directly on the Acure's colour touchscreen — no laptop or separate commissioning app is required on site. The sensor joins the inverter's LoRa network within seconds of pairing.
| Technical Specifications |
|---|
| GENERAL |
| Model |
SUNCT-RS03 |
| Communication Technology |
LoRa (sub-GHz wireless) |
| Tested Communication Range |
200 m (line of sight) |
| Max. Sensors per Acure Inverter |
2 |
| Compatible Inverters |
Sunsynk Acure Series only (SunC1 and SunC2) |
| Measurement Type |
Bidirectional AC current (grid import and export) |
| Recommended Installation Position |
Live conductor of grid incomer (between meter and consumer unit) |
| Signal Cable to Inverter Required |
None — fully wireless |
| Pairing Method |
Via Acure inverter colour touchscreen |
| Works Alongside Smartlynk Switches? |
Yes — shares the same Acure LoRa network (up to 2 CTs + 10 Smartlynks per inverter) |
Frequently Asked Questions
Is a wired CT included with the Acure inverter?
The Acure supports both wired and wireless CT connection. A wired CT is typically supplied with the inverter for standard installations. The SUNCT-RS03 is an optional wireless upgrade for situations where running a CT cable is impractical or undesirable.
Where exactly should the CT be fitted?
Clip the SUNCT-RS03 around the live conductor of the grid incomer — the cable entering the consumer unit from the meter or service cutout. Do not fit it on a neutral or earth conductor. Ensure the directional arrow on the sensor body points toward the load (consumer unit side).
Will it work reliably through thick walls?
LoRa is specifically chosen for its wall-penetrating capability. The sub-GHz signal passes through brick, blockwork, and concrete far more effectively than 2.4 GHz Wi-Fi. Real-world installations consistently achieve reliable readings through multiple floors and thick masonry at typical UK domestic and commercial distances.
Can this be used to enforce zero export on a G99 connection?
Yes. The SUNCT-RS03 feeds the Acure real-time grid current data, which the inverter uses to throttle its AC output and prevent any net export to the grid. This is the standard method for zero-export compliance on G99 connections where the DNO prohibits export or where an export cap is required.
Can I use this CT and Smartlynk switches on the same inverter?
Yes. Both share the Acure's LoRa radio. A single Acure inverter can manage up to 2 wireless CTs and up to 10 Smartlynk switches simultaneously, all communicating over the same LoRa network with no conflict or interference.
