How to connect Schrack MGRZK465 energy meter with Reduxi controller
Install the direct-connected Schrack MGRZK465 meter (65 A) and connect it to the Reduxi Controller via Modbus RTU.
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Photo of a white three-phase DIN-rail energy meter with a transparent terminal cover. Print on the front: SCHRACK, MGR2K, 1376, M18 and SI 18-11-016-MID in a box, CE mark, 3X230(400)V, 50/60Hz, 0.25-5(65)A, Class B, 1000/kWh, a star symbol. The LCD shows 230.0 V and L1. Terminals at the top are numbered 3, 6, 16 (small), 9, 11 and labelled L1, L2, L3, N. Terminals at the bottom are numbered 1, 4, 7, 10.
1 Technical documentation
The Schrack MGRZK465 is a compact, MID-certified three-phase meter for direct connection up to 65 A with an RS485 Modbus RTU interface. No current transformers are needed. The Reduxi Controller reads it over RS485 and uses it as grid meter or as a sub-meter (e.g. heat pump, wallbox, PV).
Manufacturer documents:
2 Required equipment
- Schrack MGRZK465 energy meter (3 TE, DIN rail)
- Copper conductors for the main circuit, 1.5–16 mm², and a PZ2 screwdriver (3.5 Nm)
- Twisted-pair, shielded data cable for RS485 (e.g.
LiYCY 2×2×0.5 mm²or CAT cable) - Ferrite bead for the RS485 line (recommended by Schrack)
- Reduxi Controller with a free RS485 port (terminal block
GND · A · B · 5V) - Laptop or tablet with internet access, for the Reduxi Configurator
3 System overview & wiring
The full load current flows through the meter. Measured values are passed to the Reduxi Controller via an RS485 line (Modbus RTU).
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Diagram of the system overview. Left: a white Wi-Fi router icon with four antennas, connected by a dashed teal line downwards to a globe icon with the text "www." (internet). A solid teal line labelled "Ethernet / WiFi" connects the router to the black Reduxi controller box in the top centre (label CONTROLLER on the front, RJ45 port and terminal block). From the controller's terminal block a solid teal line labelled "RS485 A/B" leads to a white DIN-rail meter at the right (print SCHRACK, display showing 230.0). A dashed teal line leads from the meter down to a house icon (the installation).
Wiring
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Diagram of the wiring between a Reduxi Controller and a Schrack energy meter. Top left: photo of a black Reduxi controller box (label CONTROLLER on the front, two RJ45 ports, USB-C port, 4-pin terminal block). Top right: photo of a white DIN-rail meter with the print SCHRACK, display showing 230.0 V and L1, terminals L1, L2, L3, N at the top. Below left: line drawing of the controller front with ports PWR, WAN, LAN and terminal block RS485 with pins GND, A, B, 5V. Terminal symbols below it: PWR (USB-C) with a line labelled 5VDC going to a Power Supply symbol; WAN (1) with a line labelled ETH_WAN; LAN (2) with a line labelled ETH_LAN; RS485 pins GND (line labelled GND), A, B, 5VDC. Two vertical labels RS485_A and RS485_B under pins A and B. Right: meter wiring diagram with terminals 3, 6, 9, 11 (top) and 1, 4, 7, 10 (bottom) around three current transformer symbols, plus small terminals 16 (top) and 15 (bottom). Mains lines L1, L2, L3 each through a 65 A fuse and N, connected to terminals 1, 4, 7 and on to the load side. A red wire labelled "RS 485_A" runs from controller pin A to meter terminal 16. A black wire labelled "RS 485_B" runs from controller pin B to meter terminal 15.
| Terminal | Function | Note |
|---|---|---|
1 / 4 / 7
|
L1 / L2 / L3 – grid side (via 65 A fuses) | 1.5–16 mm², M5, 3.5 Nm |
3 / 6 / 9
|
L1 / L2 / L3 – load side | 1.5–16 mm², M5, 3.5 Nm |
10 / 11
|
N – grid side / load side | Neutral must be connected |
16 |
RS485 A | → Reduxi Controller RS485 A
|
15 |
RS485 B | → Reduxi Controller RS485 B
|
Auxiliary terminals: 1–2.5 mm², 1.2 Nm. Always cross-check against the connection diagram printed on the meter.
RS485 connection to the Reduxi Controller
The Controller's RS485 terminal block has four pins: GND · A · B · 5V. Only A and B are used.
| Schrack MGRZK465 | Reduxi Controller |
|---|---|
Terminal 16 (A) |
RS485 A
|
Terminal 15 (B) |
RS485 B
|
| Cable shield | Earth on one side only |
4 Device configuration on the meter
The MGRZK465 is delivered with fixed factory defaults for the RS485 interface. They work with Reduxi as they are – no setting on the meter is needed for a single meter. Note them down – you will need them later (see Point 6).
| Parameter | Default |
|---|---|
| Modbus address | 33 |
| Baud rate | 19200 |
| Data bits / parity / stop bits |
8 / None / 2
|
33 and 2 stop bits by default. Entering 1 or 1 stop bit in Reduxi is the most common reason the test fails.
[menu path from the MGRZK operating manual]. Baud rate and frame format must be identical on all devices of the bus.5 Log in to the Reduxi web interface
You can open the Reduxi web interface in two ways:
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Screenshot of three Reduxi mobile app screens side by side, with cyan boxes and number badges 2 to 4. Left screen (dashboard, dark theme): menu icon at top left marked with a box and badge 2; 'reduxi' logo; tabs 'Real time data' (active) and 'Statistics'; price 5.79 € and temperature 3.2 °C; energy flow diagram with a house in the centre (-1.25 kW) and icons with values 69.0 W, 1.3 kW, 1.1 kW (red ring), -165.0 W with 97 % (red ring) and 0.0 W values at the bottom; tabs 'Power' and 'Energy'; bottom navigation: Dashboard, Diagnostics, Device control, Settings. Middle screen (side menu): 'reduxi' logo, 'Number of locations: 1233', heading 'Reduxi device management', entries '+ Add Reduxi location' and 'Reduxi devices' (marked with a box and badge 3), then 'My profile' and 'About app'. Right screen (device page): Back; picture of a black Reduxi controller with two Ethernet ports; status 'Connected'; card 'Update available': 'New update is available for your Reduxi device.' with button 'Download and install update'; card 'Connect to configurator': 'Tunnel connection enables remote access to your Reduxi configurator, without need to be connected to the same local network.' with button 'Activate tunnel connection' (marked with a box and badge 4); card 'Unit details' with field 'Unit ID'.
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Screenshot made of two parts side by side. Left part: Reduxi mobile app screen on a dark background. Top: Back button; picture of a black Reduxi controller with two Ethernet ports and a terminal block; status 'Connected' with a Wi-Fi icon. Card 'Update available': 'New update is available for your Reduxi device.' with button 'Download and install update'. Card 'Connect to configurator' with a key icon: 'Tunnel connection enables remote access to your Reduxi configurator, without need to be connected to the same local network.' and button 'Open configurator', marked with a cyan box and number badge 5. Below: card 'Unit details' with a field 'Unit ID' (value not visible). Right part: Reduxi Configurator opened in a browser, marked with a cyan frame and number badge 6. Header: back arrow, 'Tunnel connection', reload icon. Left sidebar with icons (lightning, chip, lightning bolt, bar chart, gear). Page 'Home' with a green link icon. Green notice: 'New patch available. Click here to apply.' with a close X. Time 09:12:56. Energy flow diagram with a house in the centre (1.700 kW) and icons for grid (0.000 kW), solar (1.700 kW), battery (green, 0.000 kW and 0.800 kW), a device at left (0.900 kW), electric vehicle and a charger or device at bottom. Label 'Energy manager' at the bottom.
http://reduxi.local. You can find the controller's IP address in your router's device list or in the Reduxi app under Reduxi devices.admin · Password: admin (factory default)Text description of this image
Screenshot of the Reduxi Configurator login page in a Chrome browser window. The address bar shows 'Not secure' and 'reduxi.local'; the address bar is marked with a cyan box and an enlarged copy of it (cyan box, text 'Not secure reduxi.local') is shown at the left, connected by a cyan line. Page background: light grey line drawing of a house with solar panels (green), a wall box, an inverter, a car and a charger. Top left: 'reduxi configurator' logo. Login box in the centre with title 'Login', a language selector (English flag, 'English'), a username field and a password field, and a dark 'Login' button.
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Screenshot of the Reduxi Configurator web interface after login, light theme. Top left: 'reduxi configurator' logo. Header bar: 'Home' at left, green 'Connected' status at top right. Left sidebar: expanded section 'Devices' with a list of entries, then collapsed sections 'Manager' and 'Configuration' and 'Settings'. Main area: energy flow diagram. House in the centre with ring, value 24.20 kW. Grid icon at top left, 24.20 kW (red dot on its line). Solar icon at top right, value '-'. Left icon (battery or device), 6.700 kW (green dot on its line). Right icons (battery storage and a device), values '-'. EV charger icon at bottom left, 31.00 kW. A further device icon at bottom right. Label 'Energy manager' below the house.
6 Add the Schrack MGRZK465 to Reduxi
Once the meter is wired and configured (see Point 4), add it as a new device in the Reduxi web interface.
6.1 Basic settings
Energy meterType:
Schrack MGRZK465Name: any name, e.g.
Schrack MGRZK465Include to strategy: tick Measurement devices for your strategy (e.g.
Energy manager new)Confirm with Next.
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Screenshot of the left navigation menu of the Reduxi Configurator (logo reduxi Configurator at the top). Section Devices (expanded, minus sign) lists two device icons: a car icon and a power pylon icon. Below them the entry + Add device is highlighted with a cyan box. Further menu entries: Strategies (plus sign), Utility Rate Plan, Settings (plus sign).
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Screenshot of the Reduxi Configurator wizard step titled Basic settings. Device type *: Energy meter (dropdown). Type *: Schrack MGRZK465 (dropdown). Name *: Schrack MGRZK465. Section Include to strategy: a table with columns Strategy, Measurement devices, Regulated devices. One row: Strategy: Energy manager new; Measurement devices: checkbox ticked; Regulated devices: checkbox not ticked. Buttons: Back (bottom left, outlined) and Next (bottom right, black).
6.2 Communication settings
Enter the following values – they must match the settings on the meter (see Point 4):
| Parameter | Value |
|---|---|
| Connection | Local serial port |
| Port |
RS-485 port 1 – the controller's RS485 terminal |
| Baud rate | 19200 bits/s |
| Data bits | 8 |
| Stop bits | 2 |
| Parity | None |
| Modbus Unit ID |
33 – factory default of the meter |
| Energy counter 1–4 |
Import - active energy · Export - active energy · Import - reactive energy · Export - reactive energy (default) |
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Screenshot of the form "Communication channel and device configuration" (Reduxi Configurator, light theme). Fields, all dropdowns unless noted: Connection *: Local serial port; Port *: RS-485 port 1; Baud rate *: 19200 bits/s; Data bits *: 8; Stop bits *: 2; Parity *: None; then a separator line; Modbus unit ID * (text field): 33; Energy counter 1 *: Import - active energy; Energy counter 2 *: Export - active energy; Energy counter 3 *: Import - reactive energy; Energy counter 4 *: Export - reactive energy. Buttons at the bottom: Back (left), Test communication and Done (black, right).
6.3 Test communication
Click Test communication to check whether the Reduxi Controller can read data from the meter.
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Screenshot of the bottom button bar of a Reduxi Configurator page. Left: button 'Back'. Right: button 'Test communication' (marked with a cyan box) and dark button 'Done'.
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Screenshot of the dialog "Test communication" (close X at the top right) with a green result text box: "Successful readout from device". Values: Active power: 4431.8 W; Current L1: 2.615 A; Current L2: 2.424 A; Current L3: 14.781 A; Export active energy: 1000.0 Wh; Export reactive energy: 427200.0 VArh; Frequency: 49.95 Hz; Import active energy: 844600.0 Wh; Import reactive energy: 900.0 VArh; Reactive power: -503.8 VAr; Voltage L1: 232.3 V; Voltage L2: 232.8 V; Voltage L3: 230.4 V. Then: "Additional parameter - POWER_ACTIVE_L1: 528.1"; "Additional parameter - POWER_ACTIVE_L2: 507.5"; "Additional parameter - POWER_ACTIVE_L3: 3396.1000000000004". Black button "Close" at the bottom right. The dimmed page behind the dialog is visible at the edge.
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Screenshot of the Reduxi Configurator page 'Communication channel and device configuration'. Connection *: TCP/IP (dropdown). IP *: 192.168.50.243, with button 'Scan for IP'. Port *: 502, with button 'Test port'. Modbus unit ID *: 1. Buttons at the bottom: Back (left), Test communication and Done (right). The Done button is marked with a cyan box.
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Screenshot of the dialog "Test communication" (close X at the top right) with a result box containing the red text "Unable to communicate with device." Black button "Close" at the bottom right. The dimmed page behind the dialog is visible at the edge.
7 Check the readings
In the Reduxi web interface, open Devices → Schrack MGRZK465 → Last measurements.
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Screenshot of the Reduxi Configurator device page of the meter, tab "Last measurements" selected (other tabs: Analyze, Archive, Details). Panels with rows (label, value, timestamp 08. 10. 2026 05:51:42 unless noted). Current: Current L1 2.43 A; Current L2 1.50 A; Current L3 14.81 A. Voltage: Voltage L1 232.50 V; Voltage L2 233.10 V; Voltage L3 230.40 V. Power: Active power 4.2 kW; Export active power 0.0 kW; Export active power - 1 minute average 0.0 kW; Export active power - 15 minute average 0.0 kW; Export reactive power 0.4 kVAr; Import active power 4.2 kW; Import active power - 1 minute average 4.2 kW; Import active power - 15 minute average 4.4 kW; Import reactive power 0.0 kVAr; Reactive power -0.4 kVAr. Energy: Export active energy 1.0 kWh; Export reactive energy 427.2 kVArh; Import active energy 844.5 kWh; Import reactive energy 0.9 kVArh. Other: Communication error OFF (05:51:40); Frequency 49.970 Hz.
| What you see | Meaning |
|---|---|
| Communication error OFF, values are read | Communication works. |
| Communication error ON, all values are 0 | No communication – the settings do not match. Check Point 4 and Point 6.2, or see Common issues. |
| Power with the wrong sign | Energy-flow direction reversed – see Common issues. |
✓ Summary
Wiring (Point 3): grid side to terminals 1/4/7/10, load side 3/6/9/11 (neutral is mandatory), RS485 A → 16, B → 15.
Meter setup (Point 4): nothing to change – defaults are address 33, 19200 baud, 8N2.
Reduxi (Points 5–7): add the meter as Modbus RTU device with exactly these values and confirm live readings with Test communication.
→ Common issues
| Issue | Solution |
|---|---|
| Test communication fails / no data | Check the unit ID (33), baud rate (19200), parity (None) and stop bits (2) in Reduxi. Swap the RS485 wires A/B. Check that the correct RS485 port is selected. |
| Meter shows no or implausible values | Check that the neutral conductor is connected – the meter needs it. Make sure line in/out are not swapped. |
| Communication drops occasionally | Use shielded twisted-pair cable, add the ferrite bead, earth the shield on one side, and add 120 Ω termination on long lines. |
| Several meters on one bus – only one responds | All MGRZK meters leave the factory with address 33. Give each meter a unique address before connecting them to the same bus. |