Interconnect Voltage Change and Digital Controls Upgrade
In 2019 and 2020, IEA commenced work on a complex project at an existing site where IEA had seven generators bussed to a common bus and connected to six customer loads by individual tie breaker & recloser combinations. IEA generated and interconnected to customer loads at 4,160 volts. In response to voltage upgrades planned by the local utility and transmission suppliers, IEA would now be required to interconnect at a single point at 24.9 kV.
To meet the challenges of the new interconnect requirements, IEA plans to: (1) Source and install a new 4,160/24.9 kV main transformer rated at 12/16/20 MVA (rating dependent on cooling fans configuration); (2) Source and install a new 3,000 amp, 4,160 volt single interconnect tie breaker and a fully digital control system to replace the old analog control system and programmable logic (PLC) controller. The control system upgrades were necessary because of the change from six tie connections to a single tie pont. The old PLC and its software could not be readily upgraded or modified.
Actual on-site construction time is estimated 3 months and total project costs are estimated at $1,800,000.