Downflow Clivet
The Close control units were in poor condition Aces recommended a project upgrade to extend the life of the units in line with 2 to 5 years dependent on running conditions and maintenance structures. Our proposal offered a major cost saving over new equipment and it will considerably increase the life of the existing units. Additional benefits are Refrigeration system & control improvement minimal building disruption. Carel updated new style controllers with Carel key link. This Enables software copies for future board replacement and will reduce lead time on control board failures.
Works Carried Out:
- The refrigerant was recovered into certified storage cylinders for charge confirmation.
- A pressure test was undertaken and witnessed by a representative of the client, before and after the 24-hour test period.
- A minor system leak was found.
- Brazed and tightened system bolts which included system seal replacements.
- Proposed close control upgrade/conversion DFU software carried out. Due to the nature of the works and parts the software used within the installation was custom written off site. This is not standard software. The writing of all Carel 1 tool software was undertaken using existing unit parameters to match and increase energy performance although not guaranteed.
- CONDENSER ASSEMBLIES. We modulated all condenser fan motors with new fan speed controllers, which was input from the new control, based on the desired refrigerant head pressure control. The greater control of condenser head pressure will increase the efficiency of the cooling unit and reduce the amount of energy consumption.
- CONTROLS UPGRADE. The existing controls were replaced with new Carel PCO units, which represent the most advanced offering available in the field of programmable controllers. These controllers and boards were installed into the existing electrical panels. In addition, new sensors were fitted to each circuit of the chiller and wired back to the control boards. A new style Carel controller navigator was also installed to enable navigation via parameters.
- Upon the acceptance of the drop test the nitrogen pressure was vented and the circuits evacuated down to 2torr, with a further 20-minute rise test. Each circuit was then charged with existing R407C refrigerant and test run.
- All data was logged and documented during the commissioning process and a copy of the operational report and Carel PCO3 controller configuration was given to the client.