NESTLÉ HONG KONG COMPANY

Title: System Migration for existing cooling PLC and SCADA control system in a 24 hrs operating live system, this is a big challenging on not only the technical skills, also the contingency and back-up arrangement.

Content: Upgrade of the current cooling system to new system configuration with Siemens S7 PLC controller and replace two existing chiller control panel by new control panel with new generation components UniSab 3 control unit. New controllers are not fully compatible with the existing system, we have to assist Main-contractor to re-design the control wiring and power circuit installed to the new control panel and equipment. The works also included provision of contingency and back-up system to maintain the daily operation during the site implementation period.

This back-up system mainly used to allow the both existing & new system running at the same time by activating a custom design switching component, the input and output signal were split out and feed back to two individual system to reflect the current operation status. The benefit is that it allows the existing system fully back-up the new system in the test & commissioning period to minimize the operation impact.

The works includes the following.

-Installation of new control panel with S7 PLC equipment.

-Disconnect all power & control cables from existing system and reconnect to new system.

-Replace two existing chiller control panel to new generation in cooling room

-Modify 6 numbers of cooling controller to UniSab 3 control unit.

-Modify 9 numbers of existing cooling panel to new S7 PLC remote I/O module.

-Provision of contingency and back-up system for temporary use.

- Assist for system configuration and setup