A Daikin VRV heat recovery system was commissioned 2 years ago and performed in a satisfactory manner.
Diagnosing Faulty Compressors, Daikin VRV
The System
The Customer Challenge
After 2 years, on what is a relatively rare occurrence, both of the systems’ inverter compressors were faulty.
The customer decided to change his HVAC service company, and the new company was tasked with replacing the compressors. The new compressors were installed and activated, but the root cause of the malfunction remained unknown.
The Traditional Course of Action
1
Schedule a site visit
2
Travel to site
3
Connect a service tool, and collect current, limited operational data
4
Analyze the collected data
5
Collect new data and verify the fix
The Remote Service Course Of Action
The service team performed a checkup using CoolMasterNet and CoolAutomation’s Predictive Maintenance Suite, with irregular readings found.
When both inverter compressor units were heating – they were working just fine. However, when one unit was in Heat mode and the other was Off – the unit in Heat mode was actually cooling.
Using the Predictive Maintenance Suite, the VRF expert gained remote access to the site’s data. Based on the data, he suspected a swap of control lines between the two units (in this case, AV and Bedroom 1).
A team of junior technicians was sent to the site. Upon arrival at the, they opened the ceiling, and indeed – the control lines were swapped between the units.
After fixing the issue, the team used the Predictive Maintenance Suite again. They repeated the operational sequence and saw that both units were now working correctly.
And so, the root cause was identified: the control swap was probably the major factor in the compressors’ malfunction, possibly causing liquid refrigerant to enter the suction pipe.
Using Traditional HVAC Service Vs Remote - Comparison Table
| Traditional HVAC Service | Remote HVAC Service |
|---|---|
Extended on-site data waiting for the error to re-emerge (which will not happen when both units are turned on) | Offsite remote system test and fault detection |
Multiple trips to the site are expected | Less than 1 hour of on-site junior VRF technicians time |
Analysis of the raw data gathered with minimal assistance from the tool, involving a senior VRF expert on-site for a considerable amount of time | Remote fix verification |
On-site fix | |
On-site verification test |
The Result
1
Remote diagnostics
Access the system remotely from the comfort of the office to test the system and find the fault
2
Less than 1 hour of on-site junior VRF technician time
Send a junior VRF engineer for 1 hour on-site to perform the fix
3
Remote fix verification
Verify the fix remotely
Benefits
Minimal customer disturbance
One onsite visit, versus multiple visits
Simplified data analysis