KNX Panel Testing and Commissioning: From Insulation to ETS6 Group Monitor

Pre-Power Testing

Before applying any voltage to the panel, perform these tests with the panel de-energised and all MCBs in the OFF position:

Visual inspection: verify all terminal screws are torqued — 1.0 Nm for 0.75-1.5mm² terminals, 2.0 Nm for 2.5-4mm² per IEC 60999-1. Inspect for damaged insulation (nick marks from screwdrivers). Confirm KNX TP polarity: red to the plus (+) terminal, black to the minus (−) terminal on all KNX bus distribution points. Verify PE (green/yellow) continuity from DIN rail sections to PE busbar (visual only at this stage).

Insulation resistance test: disconnect all KNX devices from TP bus (or leave connected — KNX TP bus operates at 30VDC SELV and is not affected by 500V insulation test on the AC side, but verify with device manufacturer). Test 230VAC phase-to-neutral, phase-to-PE, neutral-to-PE: minimum 1 MΩ at 500VDC (Metrel MI3102H or Fluke 1587FC). Result below 1 MΩ: investigate for cable pinch under terminal screws, damaged conduit entry, or damp enclosure.

Earth continuity test: using KMT 50A continuity tester (or Metrel MI3102H in continuity mode, 200mA test current per IEC 60364-6): from PE busbar to each metallic enclosure part, each DIN rail section, and every switchgear earth terminal. Maximum 0.1 Ω per IEC 60364-6 requirements.

Bus Power-Up Sequence

Step 1 — Apply 230VAC supply to KNX PS
  Measure bus voltage at KNX PS terminals:
  Target: 29-31 VDC (nominal 29V DC per KNX standard)
  Measure at furthest KNX device on the bus:
  Minimum: 21.6V (KNX minimum at device)

  If voltage drop excessive:
  YCYM 2x0.8mm2 = 27 ohms/km per conductor
  Max recommended bus segment length: 350m (standard PS)

Step 2 — Verify bus current
  KNX PS current output must not exceed rated capacity:
  MDT STC-0640.01: max 640mA
  Typical: 20 devices x 15mA = 300mA (within capacity)

Step 3 — Check for bus short circuit
  ETS6 bus monitor: no repeated reset cycles
  Short on KNX TP: voltage below 21V + current spike

ETS6 Programming Sequence

Step 1 — Physical address assignment: in ETS6, connect KNX USB interface (MDT USB-IP) to programming laptop. Topology view: select device, click 'Individual Address Download'. Press programming button on physical device (LED flashes). ETS6 confirms address assigned.

Step 2 — Application download: select device, click 'Download' (full application). For a 20-device panel: allow 5-8 minutes total. Download order: KNX PS and line couplers first, then actuators, then sensors and logic modules.

Step 3 — Group address download: all group addresses and flags (Communication Objects) are downloaded with the application. Verify in ETS6 'Group Monitor' that GAs are correctly linked by using the 'Read' function on value-bearing objects.

Functional Test with Group Monitor

ETS6 Group Monitor: open via 'Bus' then 'Group Monitor', then press 'Start Monitoring'.

1. Send telegram GA 1/0/0 (Channel 1 switch, DPT 1.001, value 1)
   Expected: actuator relay 1 closes, connected load activates

2. Verify status feedback GA 1/0/1 returns value 1
   (if status feedback object is configured in ETS6)

3. Send value 0 to GA 1/0/0
   Expected: relay opens, load deactivates

4. Repeat for channels 2, 3, 4 (GAs 1/0/2 through 1/0/7)

5. Central ON test: send 1 to GA 0/0/0 (DPT 1.001)
   Expected: all channels activate simultaneously

Blind actuator (MDT JAL-0410.02) test:
  Send 0 to GA 3/0/0 (move down, DPT 1.008)
  Verify motor runs
  After 2s: send 1 (stop)
  Read position GA 3/0/2 (DPT 5.001) — should reflect partial travel

Final Panel Documentation

Panel test report (IEC 60364-6 Verification Report minimum contents): date, tester name, panel ID, supply voltage measured, insulation resistance values per circuit, earth continuity values, bus voltage measured at PS and at furthest device, list of devices tested with individual address confirmed. Sign and file with building O&M manual.

Programming backup: export ETS6 project file (.knxproj), save to shared drive AND leave USB copy in panel door pocket. Label USB drive with project name, date, and ETS6 version. A .knxproj file without a version note becomes problematic if the ETS6 version used to create it is no longer installed — always record the ETS6 version (e.g. ETS6.2.1) on the USB label.