NodOn SEM-4-3-20

Compatibility

Compatible with EpiSensor Edge over Zigbee.

Pair it with the Zigbee radio on an EpiSensor Gateway. Edge reads it locally on the Gateway.

Edge reads 32 values from it, listed under Interface.

Connect it with

• 
  Gateway ZGW-20
  From €899 ex VAT Configure Gateway

Specifications

The SEM-4-3-20 is a DIN-rail meter 18 mm wide with three split-core current transformers that clip around the conductors, so it can be added to an existing board without disconnecting any cables. It takes its supply and its voltage reference from the LA, LB, LC and N terminals, and reports voltage, current, active, reactive and apparent power, power factor, frequency and energy for each phase over Zigbee 3.0.^1, 2

Power

Self-powered from the measured supply. Takes its supply from the voltage terminals: 220 to 240 V AC line to neutral or 380 to 415 V AC line to line, 2 VA maximum.¹

Poles

3P+N, single-phase and three-phase compatible¹

Measurement range

50 mA to 70 A per phase (_70A) or 50 mA to 120 A per phase (_120A)¹

Accuracy

Class 1.0 (±1 %), IEC 61557-12¹

Overvoltage category

III¹

Rated insulation voltage

440 V¹

Wireless

Zigbee 3.0, 2.4 GHz, +10 dBm maximum¹

Wired interface

Modbus RTU over RS-485¹

Operating temperature

-25 to 70 °C¹

Protection

IP20, indoor use¹

Dimensions

113.7 × 18 × 65.9 mm (H × W × D) without clamps, one DIN module¹

Weight

48 g, plus 3 × 58 g clamps (70 A) or 3 × 72 g clamps (120 A)¹

Order code, 70 A clamps

SEM-4-3-20_70A, EAN 3700313926512¹

Order code, 120 A clamps

SEM-4-3-20_120A, EAN 3700313926536¹

Where it is used

• Three-phase distribution boards and sub-mains, where one module fits in a single DIN slot and the clamps go on without disconnecting cables.

  Transformer and distribution board monitoring

• Solar PV and battery sites, where separate consumed and produced counters per phase show import and export.

  Solar PV monitoring

• EV charge points, where live power per phase can drive load management against the supply limit.

  EV charging load management

• Three single-phase tenant or zone circuits from one meter, for cost allocation in shared buildings.

  Tenant submetering and cost allocation

Interface

Readings and settings, with units and ranges where NodOn publishes them. R readable, W writable only.⁵

Phase A has no suffix in the property names: power, voltage, current, power_factor, power_reactive and power_apparent are phase A, and the _phase_b and _phase_c properties are the other two.⁵

The meter reuses the metering cluster’s tier 1, 2 and 3 summation attributes for phase A, B and C energy. They are not tariff registers.⁵

Energy reset uses the Basic cluster’s reset-to-factory-defaults command, which clears the counters but keeps the meter on the network with its bindings and reporting.⁵

Setup

1. Wire it with the supply isolated

   Switch off at the main breaker, clip the meter onto the DIN rail and connect LA, LB, LC and N downstream of an overcurrent protection device. Fit clamp IA on phase A, IB on phase B and IC on phase C, each with its arrow in the direction of current flow.²

2. Power up and check the LED

   Close the panel and switch on. A red LED flashing every second means a fault or a wiring error: switch off at once and check the protection device, L and N and the clamps.²

3. Open pairing in Edge

   In Edge, open pairing on the Gateway’s Zigbee network.

4. Put the meter into pairing mode

   Press and hold the RESET button until the green LED flashes quickly, twice a second. A steady green LED means the meter has joined.²

5. Check each phase

   Confirm that Edge identifies it as NodOn SEM-4-3-20, then compare each phase’s current with a clamp meter. A phase that reads export while the load is consuming has its clamp reversed or paired with the wrong voltage.²

Common questions

Does the SEM-4-3-20 need a NodOn hub to work with Edge?

No. It is a Zigbee 3.0 device and NodOn states it works with a Zigbee-compatible hub, so it joins the Zigbee radio on an EpiSensor Gateway directly.^1, 3

Can it measure three separate single-phase circuits?

Yes. NodOn documents a wiring scheme with one clamp on each of three single-phase circuits and L and N as the shared voltage reference. Each clamp then reports as one of the three phases.²

Does it measure exported energy from solar PV?

Yes. It measures in both directions and reports consumed and produced energy for each phase and in total. Energy only counts the right way if each clamp’s arrow points in the direction of current flow from the supply.^1, 2

Why are the energy readings wrong after installation?

NodOn lists three causes: phase and neutral swapped, a clamp paired with the wrong voltage input, or a clamp fitted against the direction of current. Check the connections, the VA-IA, VB-IB and VC-IC pairing and the clamp arrows.²