Balance of system · July 2026

A metering accessory is where a vendor's market intent shows up first.

A current-transformer power sensor is the least glamorous item in a home energy system and one of the most revealing. It is the part that has to speak the local grid's language. Sigenergy's Sigen Power Sensor has moved to a new -WI generation, and the change visible in the published documents is not the wireless radio. It is the certification line.

What the prior datasheets published

The -DH generation datasheet covers Sigen Sensor 1, SP-DH, SP-CT120-DH, TP-DH and TP-CT120-DH. It lists RS485 as the sole communication interface, at 9,600 bps, Modbus RTU; voltage accuracy 0.5%, current accuracy 0.5%, power accuracy 1%, frequency accuracy 0.2%; operating temperature −30 to 60 °C; and standard compliance EN 61010-1:2010, EN 61010-2-030:2010. Source: Sigenergy, Sigen Power Sensor datasheet, sigenergy.com, retrieved 23 July 2026.

The later CT100 generation datasheet covers Sigen Sensor 1, SP-CT100, TP-CT100, TP-CT300 and TP-CT600. It carries the same interface line (RS485 only, 9,600 bps, Modbus RTU), the same measurement accuracies, an operating range widened to −25 to 65 °C, and the same two European standards. Source: Sigenergy, Sigen Power Sensor 100s datasheet, retrieved 23 July 2026 from a distributor-hosted copy; Sigenergy is named as the document's author and the file is dated October 2025.

Two generations, one communications path, one standards line. Neither document names an Australian certification mark or an Australian demand-response function.

Three published generations

The market signal appears in the document trail

1. -DH One wired path

   RS485 at 9,600 bps, European EN safety standards, and an operating range of -30 to 60 °C.

2. CT100 The same standards line

   RS485 remains fixed at 9,600 bps; the operating range widens to -25 to 65 °C.

3. SP-CT100-WI Australia enters the record

   2.4 GHz WLAN, selectable RS485 rates, CE and RCM certification, and named Australian DRM pins.

What the -WI guide publishes

The Sigen Sensor SP-CT100-WI installation guide is version 01, release date 5 March 2026. Its key-parameter table lists WLAN at 2.4 GHz; RS485 baud rates of 2400, 4800, 9600 (default), 19200, 38400 and 115200 bps; electricity metering accuracy Class 1, error within ±1%; operating temperature −40 °C to +70 °C; DIN rail 35 mm mounting; and certification: CE, RCM. Source: Sigenergy, Sigen Sensor SP-CT100-WI Installation Guide, version 01, released 2026-03-05, sigenergy.com, retrieved 23 July 2026.

review.solar

Sigen Power Sensor · published RS485 ceiling

The default speed is unchanged; the ceiling is not

Prior datasheets9,600

single published rate

SP-CT100-WI115,200

9,600 retained as default

Chart data

Series	Value	Note
Prior datasheets	9,600	single published rate
SP-CT100-WI	115,200	9,600 retained as default

The pin assignments are the Australian tell

The guide's RJ45 port table assigns pins 1 to 4 as digital inputs 1 to 4, "or DRM5 for Australia", "or DRM6 for Australia", "or DRM7 for Australia" and "or DRM8 for Australia" respectively. Pin 5 is signal ground. Pin 6 is named DRM0, "DRM0 for Australia". Pins 7 and 8 carry RS485 terminals A and B. The guide describes the RJ45 port as being "for power scheduling, such as DRMs and Ripple control". Source: Sigen Sensor SP-CT100-WI Installation Guide, version 01, port description and RJ45 pin table.

Demand response modes are the mechanism Australian standards use to let a network operator curtail or shed a connected device. A device whose published pinout names DRM0 and DRM5 through DRM8 has had the Australian requirement designed into its wiring, not adapted around it. Paired with the RCM mark (the compliance mark applied to electrical equipment supplied in Australia and New Zealand), the published document describes a device intended for supply into this market.

What the public record does not establish

Three limits are worth stating, because the absence of a document is not evidence of a product.

• Three-phase -WI variants. Only the single-phase SP-CT100-WI has a published Sigenergy guide located at the time of writing. Three-phase equivalents to TP-CT100, TP-CT300 and TP-CT600 are not covered by any Sigenergy document we could retrieve.
• Bluetooth. The SP-CT100-WI guide names WLAN at 2.4 GHz. It does not mention Bluetooth anywhere in its eleven pages.
• Which devices the wireless mode serves. The guide's two recommended networking scenarios are "for Sigenergy Inverters with WLAN" (sensor and inverter on the same router network) and "for Sigenergy Inverters with RS485". It publishes no restriction of the wireless mode to a named subset of Sigenergy products.

Why a sensor generation belongs in a product record

Accessory-level documents are ingested into the catalogue for the same reason datasheets are: they are dated, versioned, first-party, and they change. A metering device that gains a wireless path keeps a wired one at its former default rate, so an installed base does not strand. A metering device that gains an RCM mark and a DRM pinout has had a market decision made about it. Neither of those facts appears in a product's headline specification, and both are load-bearing for anyone deciding what a system will still be able to do in five years.

This piece reads only what Sigenergy has published. Where the published documents are silent (the three-phase variants, Bluetooth, any device-pairing restriction), that silence is recorded as silence and nothing is inferred to fill it.

Sourcespublished vendor documents

• Sigenergy, Sigen Sensor SP-CT100-WI Installation Guide, version 01, release date 2026-03-05. Key parameters table, port description and RJ45 pin table, and recommended system networking scenarios. Hosted on sigenergy.com, retrieved 23 July 2026.
• Sigenergy, Sigen Power Sensor datasheet covering Sigen Sensor 1, SP-DH, SP-CT120-DH, TP-DH and TP-CT120-DH. Measurement accuracy, communication and standard compliance tables. Hosted on sigenergy.com, retrieved 23 July 2026.
• Sigenergy, Sigen Power Sensor datasheet covering Sigen Sensor 1, SP-CT100, TP-CT100, TP-CT300 and TP-CT600, dated October 2025. Retrieved 23 July 2026 from a distributor-hosted copy; Sigenergy is named as the document's author. No copy of this generation's datasheet was located on sigenergy.com at the time of writing.

Sigenergy products are scored in the review.solar battery and inverter catalogues under the same rubric applied to every other manufacturer. This note reports published documents and does not alter any product score.