SolaX M1-40 1-Phase CT Energy Meter | 100A/40mA CT | RS485

Description

The SolaX M1-40 is a single-phase indirect (CT-connected) energy meter for homes and small businesses. It measures voltage, current, power and frequency at the grid connection point and sends the readings to your SolaX inverter, so the system can manage battery charging, limit export and show self-consumption.

This pack includes a 100A/40mA CT on a 2m lead and a 5m communication cable, making it a plug-and-play CT solution. A 50ms refresh rate gives fast, precise control, intelligent CT direction adjustment automatically resolves installation errors, and settings can be changed remotely from the SolaXCloud app.

At only 18mm wide it clips onto a 35mm DIN rail inside the distribution board. It talks to the inverter over RS485, or wirelessly through a SolaX Wi-BR bridge (sold separately), and it offers Class 0.5 voltage and current accuracy across a -40°C to 70°C operating range.

1P2W

Single-Phase Grid

100A/40mA

CT Supplied

50ms

Refresh Rate

Class 0.5

Voltage & Current

18mm

DIN-Rail Width

RS485

Inverter Link

Single-Phase Supplies Only

The M1-40 is for single-phase connections (1P2W, 220 to 240V). For a three-phase supply use the M3-40 or M3-40-Dual.

Use 40mA-Output CTs

SolaX M-series meters take 40mA-output CTs. The CHINT DTSU666-CT meters use a different type, 5A-output CTs, and the two types are not interchangeable. The pack CT is 100A/40mA, which is SolaX's recommended rating for this meter.

Important Safety Information

Installation must be carried out by a qualified electrician to BS 7671, with the supply isolated before any wiring is done. Connect the voltage and CT wires exactly as shown in the SolaX quick installation guide and fit the CT around the correct conductor. Terminal screws are tightened to 0.45 N·m.

Plug-and-Play CT

A 100A/40mA CT (2m lead) and a 5m COM cable are in the pack, so no extra parts are needed for a standard install.

50ms Refresh

A 50ms refresh rate supports more precise and faster control of storage and export.

Automatic CT Direction

Intelligent adjustment of CT direction automatically resolves installation issues if a CT is fitted the wrong way round.

Remote Settings

Change settings remotely through the SolaXCloud app, saving a return visit.

Safe Isolation

Separates strong and weak currents for enhanced electrical safety.

Compact DIN-Rail Unit

Just 18mm wide on a 35mm DIN rail, with a display and a button to switch between readings.

Supply

Inverter Series

Connection

RS485 A / B Pins

Single-phase

X1-HYB G4, X1-FIT G4, X1-IES, X1-VAST

RJ45

4 / 5

Single-phase

X1-MINI G4, X1-BOOST G4

RJ45

4 / 5

Single-phase

X1-HYB LV

RJ45

4 / 5

Single-phase

X1-AC

RJ45

7 / 8

Single-phase

X1-SMART G2

Quick-connect terminal

4 / 5 or 11 / 12

About the Pin Numbers

Pins are the inverter's 485A / 485B terminals. On the X1-SMART G2 two pairs of terminals are available and the two pins in the same box are a pair. Wiring for each inverter is in the SolaX quick installation guide.

Electrical

Power grid type

1P2W

Rated voltage

220 to 240V

Operating voltage

100 to 288V

Current input

*A / 40mA (via CT)

Frequency

45 to 65Hz

Frequency tolerance

0.01Hz

Measurement

Accuracy, voltage and current

Class 0.5

Accuracy, active power

Class 1

Accuracy, reactive power

Class 2

Resolution

Active power 0.1W, frequency 0.001Hz

Refresh rate

50ms

CT supplied

100A/40mA

Other CT rating listed by SolaX

200A/40mA

Communication

Wired

RS485

Wireless

SolaX Wi-BR bridge (sold separately), up to 200m horizontal and 20m vertical in SolaX lab tests

Environment & Mechanical

Operating temperature

-40 to 70°C

Operating humidity

95% RH or below (non-condensing)

Operating altitude

Below 4,000m

Degree of protection

IP20

Dimensions (W x H x D)

18 x 100 x 65.5mm

Mounting

35mm DIN rail, inside the distribution board

Cables & Contents

Voltage cable (installer supplied)

Multi-core copper, 1.5 to 2.5mm²

COM cable

Shielded twisted pair, 0.25 to 1.5mm²

Terminal screw torque

0.45 N·m (M2), 7mm strip length

In the pack

M1-40 meter, 1 CT (2m lead), 5m COM cable, document

What does the M1-40 do?

It measures the electricity flowing at the grid connection point and reports it to the SolaX inverter. The inverter uses this to control battery charging, limit export and track self-consumption. SolaX's knowledge base states that a meter or CT is needed for export control.

Is it for single-phase or three-phase?

Single-phase only (1P2W, 220 to 240V). For three-phase supplies, see the M3-40 and M3-40-Dual.

Which SolaX inverters can I connect it to?

The single-phase X1 series: X1-HYB G4, X1-FIT G4, X1-IES, X1-VAST, X1-MINI G4, X1-BOOST G4, X1-HYB LV, X1-AC and X1-SMART G2. The table above gives the RS485 pins for each.

Which CT do I need?

A 100A/40mA CT is included and is SolaX's recommended rating for this meter. SolaX's quick guide also lists a 200A/40mA CT. Confirm any other rating with SolaX before ordering.

Where does it go in the system?

Install it between the grid and all home loads, normally in the main distribution board, on a 35mm DIN rail. Connect all cables before mounting it on the rail.

Can it work wirelessly?

Yes, with a SolaX Wi-BR wireless bridge (sold separately). SolaX quotes up to 200m horizontally and 20m vertically from its own lab tests, so real-world range depends on the building.

BTU Calculator

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Room Dimensions

Length (in m):

Width (in m):

Height (in m):

Room Type

Living Room

Bedroom

Kitchen

Bathroom

Conservatory

Hallway

Glazing Type

Single Glazed

Double Glazed

Triple Glazed

External Walls

0 Wall

1 Wall

2 Walls

3 Walls

4 Walls

Insulation Level

Poor

Average

Good (New Build)

Calculate

Required Heating

0

Watts

0

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