Ballance’s Hewletts Road plant in Mount Maunganui produces superphosphate, the most common fertiliser used in New Zealand farming. Ergo is providing advice, design and protection settings for the upgrade of the generator protection, excitation, control and auxiliary support systems. The existing systems are past their useful life and lack the facility for fault analysis.
The proposed upgrades will address the fault-finding limitations by replacing the existing GEC electromechanical protection relays and Siemens excitation control with electronic relays. These will provide reliability and visibility to the protection engineer, with time stamping of trip events to within 100ns.
Ergo has specified and integrated a new 110V DC auxiliary system which will greatly improve the reliability and ability to test the system. The existing electromechanical AC & DC MCC is being replaced with a new PLC based solution.
The main challenges with the project have been existing documentation and a short window of time to complete the construction. We spent a week on site at the beginning of the project to gather and verify all available documentation. The installation time restraints have been managed by providing prefabricated replacement panels for all upgrades.