The American Samoa Power Authority will bring in 4.5MW of rental generators to improve the security of power supply on Tutuila.
According to Wallon Young, ASPA’s Power Chief, this became necessary after heat cracks were found on the crank pins on two of ASPA’s largest generator sets, T-2 and T-6 at the Tafuna power plant.
These heat cracks rendered the crankshafts on both gen-sets un-usable, meaning both crankshafts have to be replaced.
The heat wave affecting the territory is not only stressing the cooling systems on the remaining gen-sets, but have increased the peak loads by 2MW.
The rental generators will be used for at least three months, as it will take ASPA about the same time to replace one of the damaged crankshafts.
The new 23MW Satala power plant isn’t ready to provide any support as yet, because it will not be commissioned until May 30, 2016.
The heat cracks are not visible to the naked eye, but were detected recently by Magnetic Particle Inspection (MPI) testing.
The heat cracks were the result of bearing failures on T-2 and T-6.
ASPA operates 17 generator sets on Tutuila but with two generators down, all fifteen remaining gen-sets have to be operated at their maximum capacity – to supply Tutuila’s peak load of 24 MW.
Young says without T-2 and T-6, there are no standby or reserve generators available during peak load periods that occur on week-days, between 9am to 4 pm and from 7pm to 10 pm – hence the call for the rental generators.
ASPA had engaged the services of crankshaft specialist Goltens’ Singapore to grind down the damaged crankpins- to remove the heat cracks; unfortunately the procedure was unsuccessful.
The rental generators will cost ASPA approximately $232,000 over the next three months.
