General Air Conditioning | Technical Service Procedure
VRF Service Tool Standard Operating Procedure
Connection, monitoring, operation control, function setting and system-data archiving
Authorised technicians only: This procedure is intended for trained service personnel working on General VRF systems. Confirm safe access, communication wiring integrity and correct system identification before making any operational or function-setting changes.
Critical requirement: The WIBU Key must be connected before launching the Service Tool. Without the key, the software will not operate. Store the key securely because replacement units are difficult to obtain.
Required equipment Connect and scan Monitor system Control operation Function settings Save BAK file
1. Purpose and scope
This SOP explains the basic use of the General VRF Service Tool for commissioning, system monitoring, fault diagnosis, operational testing, indoor-unit function setting, controller time synchronisation and archiving of service data.
It applies to service technicians responsible for commissioning, diagnosing and maintaining General VRF systems and network converters.
2. Required equipment
| Equipment | Purpose and requirements |
|---|---|
| WIBU Key | USB software-licence key. Insert it before launching the VRF Service Tool. Keep it in a secure location. |
| Echelon adaptor | Provides communication between the laptop and the VRF network. One end connects by USB; the other has two snap terminals for the two-core Dekoron cable. |
| Dekoron cable | Connects the adaptor to the VRF communication circuit. Keeping approximately 2–3 m attached to the adaptor is recommended for repeated site use. |
| Service laptop | Must have the VRF Service Tool installed and the required adaptor drivers configured. |
3. Connection and login
Step 1 — Connect the hardware
- Insert the WIBU Key into the laptop.
- Connect the Echelon adaptor to the laptop by USB.
- Connect the Dekoron cable to the adaptor snap terminals.
- Connect the cable to any suitable point on the X1/X2 communication circuit or to the Z1/Z2 terminals at the outdoor unit.
Step 2 — Launch and log in
- Open the VRF Service Tool from the desktop shortcut.
- Enter the configured credentials. The example default credentials are:
| User ID | vrfvrf |
| Password | vrfvrf |
Tick the option to save the User ID and Password only where permitted by company security requirements.
4. Select the work mode
| Mode | Use |
|---|---|
| Online Work | Use when connected to a live VRF system. |
| Offline Work | Use to review a previously saved BAK file without connecting to a live system. |
Enter a clear project name, such as Her Majesty’s Theatre, then select OK.
5. Configure the USB port
- Open USB Checker.
- Select the USB port assigned to the Echelon adaptor, for example USB3.
- Press Light.
- Confirm the SVC indicator flashes in sync with the selected adaptor.
If the SVC light does not respond: select another listed USB port, confirm the adaptor driver is installed, and verify that the adaptor is connected securely.
6. Address and network scan
- Select the required Ref. No. range to match the addressed refrigerant systems.
- When the refrigerant-system number is unknown, or incorrect addressing is suspected, select All.
- Use Checked Address to open Address Checker and confirm the addresses visible on the circuit.
- Start the scan and allow the tool to collect the system information.
7. Confirm the system overview
After a successful scan, the overview should display all outdoor units, indoor units and, where installed, RB units.
Missing equipment: If an expected outdoor, indoor or RB unit is not shown, investigate communication wiring, address settings, refrigerant-system numbering and registration before continuing.
8. Detailed monitoring
Open the Detail tab to view live system information. Available data can include:
| Thermistor temperatures (°C) | Electronic expansion valve pulses |
| Solenoid operation | Compressor speed (rps) |
| Fan speed (rpm) | High and low pressure (MPa) |
| Saturation temperatures (°C) | Outdoor, indoor and RB operating states |
Use these values to assess system operation, compare actual conditions against expected performance and support fault diagnosis.
9. Control connected units
- Select the Operation Control icon.
- Select the required refrigerant system. Only one refrigerant system can be commanded at a time.
- Choose the operating mode, temperature, fan speed and any other required settings.
- Press SEND to apply the command.
- Where required during diagnostics, enable R.C Prohibit to prevent local users from changing or stopping the units.
Operating indication: Systems that are running are shaded green in the interface.
10. Operational confirmation
Review live data and confirm that the selected system is operating correctly and efficiently.
Before disconnecting: Turn all commanded units OFF and release any R.C Prohibit setting applied during the service session.
11. Indoor-unit function settings
- Right-click the Service Tool icon.
- Select Maintenance → Remote Setting.
- Select the required function from the dropdown list.
- Enter the required value in the Set field.
- Press SET.
- Press WRITE to send the setting to the selected indoor units.
Verification: Confirm that the intended units received the setting and record the original and revised values in the service documentation.
12. System time synchronisation
- Select Maintenance → System Time Setting.
- Confirm the date and time populated from the laptop are correct.
- Select OK to broadcast the time to all connected wall controllers.
- Confirm memory backup is enabled on wall controllers so the time is retained after a power interruption.
13. Save and archive the BAK file
- When the service session is complete, select Save Export File.
- Save the file into a clearly named site folder using a format such as SiteName_YYYY-MM-DD.
- Retain the resulting .BAK file with the commissioning or service report.
- After the file is saved, the Service Tool will close.
Record retention: The BAK file provides a baseline of the system configuration and operating data and should be retained for future comparison, diagnostics and recommissioning.
14. Troubleshooting guide
| Issue | Checks |
|---|---|
| Software will not open | Confirm the WIBU Key is inserted and detected. |
| No adaptor response | Check USB port selection, adaptor driver, cable connection and SVC light response. |
| No devices found | Check X1/X2 or Z1/Z2 communication wiring continuity, polarity requirements where applicable, system addressing and adaptor port assignment. |
| Some units are missing | Use Checked Address, scan All refrigerant systems, and verify unit addressing and communication wiring. |
| Commands not applied | Confirm the correct refrigerant system and units were selected, then press SEND. Check for local restrictions or communication faults. |
| Function setting not retained | Confirm both SET and WRITE were completed, then rescan or reopen the setting to verify the stored value. |
15. Completion checklist
| ☐ | All expected outdoor, indoor and RB units were identified. |
| ☐ | Live operating values were reviewed and recorded where required. |
| ☐ | Any function-setting changes were documented and verified. |
| ☐ | All units were turned OFF before disconnecting. |
| ☐ | R.C Prohibit was removed. |
| ☐ | The BAK file was saved and archived with the service or commissioning report. |
| ☐ | The WIBU Key and Echelon adaptor were removed and stored securely. |
Reference: Fujitsu Assist VRF Service Tool training material. Always use the latest approved software, service documentation and site-specific commissioning records.