Panasonic's PAC-i H-series VRF system is widely specified in European commercial buildings for its high COP, R32 refrigerant, and the CZ-CAPRA1 adapter — a native KNX TP interface that integrates each indoor unit directly into the KNX installation without Modbus gateways or third-party translators. This guide covers the CZ-CAPRA1 adapter hardware, indoor unit PCB connection, ETS6 application import, group address assignment, and multi-zone commissioning.

PAC-i H-series VRF overview

Panasonic PAC-i H-series outdoor units: 3-phase inverter compressor, R32 refrigerant (2023+ models), capacity range 8–56kW, COP up to 4.3 heating / 4.0 cooling. Indoor unit types: cassette (S-36/45/56PY3E), ducted (S-200/250PYE), wall-mount (CS-Z series, Etherea), ceiling concealed. All indoor units connect to the outdoor unit via the H-LINK II (Panasonic proprietary 2-wire bus, 12V signalling) for refrigerant control and defrost coordination. Each indoor unit also has an indoor–indoor bus connector (M-NET sub-bus) for remote controller and BMS adapter connection. The CZ-CAPRA1 connects to the M-NET port — not to H-LINK II — for building control integration.

CZ-CAPRA1 adapter hardware

The CZ-CAPRA1 is a DIN-rail module (35mm rail, 4 modules wide, 24V DC powered from external PSU or KNX bus coupler). Connections: (1) M-NET bus (2-wire, indoor unit PCB terminal block X1A, pins 1 and 2 — polarity matters). (2) KNX TP bus terminal (KNX standard colours: red +, black −, grey shielded). (3) 24V DC power input (via KNX bus or external 24V SMPS). One CZ-CAPRA1 per indoor unit (or per outdoor unit in heat pump mode). Physical addressing: ETS6 programming button on CZ-CAPRA1 face — standard KNX TP individual address assignment. M-NET wiring: use Panasonic-specified 2-core shielded cable (Panasonic P/N VVHF-B3 equivalent), max 70m from indoor unit M-NET terminal to CZ-CAPRA1. Do not extend with unshielded cable — M-NET is noise-sensitive.

ETS6 application import and parameters

Download Panasonic KNX application database from Panasonic HVAC partner portal (requires registration). Import: ETS6 > Catalogues > Import OPC > select Panasonic .knxprod file. Add CZ-CAPRA1 to ETS6 project, assign individual address. Parameters tab: (1) Indoor unit address on M-NET: set to match M-NET address configured in indoor unit PCB DIP switches (DIP1–DIP4, address 0–15 per system). (2) Operation mode: cooling/heating/auto/fan/dry — select available modes to expose as KNX objects. (3) Temperature setpoint range: min/max (16–30°C recommended). (4) Periodic status sending: enable 60-second cyclic sending of room temperature feedback. (5) Fault code objects: enable to receive DPT 5 fault code telegrams for BMS alarm integration.

Group object assignment

CZ-CAPRA1 KNX group objects: (1) On/Off — DPT 1.001, write/read. GA: 7/room_no/0. (2) Operation mode — DPT 20.105 (HVAC mode: 0=Auto, 1=Heat, 3=Cool, 9=Fan only, 14=Dry). GA: 7/room_no/1. (3) Setpoint temperature — DPT 9.001 (2-byte float, °C). GA: 7/room_no/2. (4) Room temperature feedback — DPT 9.001, read-only, from indoor unit NTC sensor. GA: 7/room_no/3. (5) Fan speed — DPT 5.001 (0=auto, 1=low, 2=medium, 3=high). GA: 7/room_no/4. (6) Fault status — DPT 1.001 (0=OK, 1=fault). GA: 7/room_no/8. (7) Fault code — DPT 5.010 (0–255 fault codes, reference Panasonic service manual). GA: 7/room_no/9. Link group objects to GAs in ETS6 Group Address editor. Use ETS6 template: configure one unit completely, then copy-paste to remaining units adjusting only room_no in GA.

Multi-zone system commissioning

12-indoor-unit office floor: one PAC-i H-series outdoor (56kW, H-LINK II), 12 indoor units (M-NET address 0–11), 12 CZ-CAPRA1 adapters. Commissioning sequence: (1) Commission PAC-i outdoor + indoor refrigerant circuit first (Panasonic field engineer, leak test, nitrogen pressure test, vacuum, refrigerant charge). (2) Configure M-NET address DIP switches on each indoor unit PCB (unit 0 = reception, unit 1 = office 1, etc.). (3) Wire M-NET cable from each indoor unit to its CZ-CAPRA1. (4) ETS6: assign individual addresses 1.1.51 through 1.1.62 to each CZ-CAPRA1 (line can be shared with other KNX devices). (5) Download ETS6 parameters to all 12 adapters. (6) Test: from ETS6 Group Monitor, send On/Off to each unit, observe indoor unit LED indication, verify room temperature feedback received within 60 seconds. (7) Set operation mode: DPT 20.105 value 9 (Fan only) for all units → confirm fans running, no cooling/heating → confirms KNX control functioning. (8) Handover: configure BMS polling of fault code GAs via KNXnet/IP for remote monitoring.

Integration with BMS and energy metering

Panasonic PAC-i supports central energy monitoring via the Panasonic integrated energy monitoring system (IMES, optional outdoor unit add-on, CZ-CAPRA1 also provides energy data object). KNX energy monitoring: CZ-CAPRA1 exposes DPT 12.001 (energy Wh counter) as a KNX group object (if enabled in parameters). Link to Gira X1 or ARISTO KNX server — visualise energy consumption per floor/zone. For BMS Modbus integration: use MDT KNX-Modbus gateway alongside CZ-CAPRA1 — CZ-CAPRA1 handles individual unit KNX control, MDT gateway aggregates to Modbus for BACnet BMS. Alternatively, Intesis INKNXPAN001I000 (Intesis KNX to Panasonic VRF gateway using P1/P2 protocol — alternative to CZ-CAPRA1, lower cost per indoor unit in large systems with 16+ units).