A large local petrochemical company requested Marthinusen & Coutts (M&C) in mid-2021 to take the lead in the redesign and quality management of a stator rewind process for a 17MW compressor drive synchronous motor that had failed during operation.
The motor is a hazardous area zone certified motor as it operates in a potentially extremely explosive environment of hydrogen and acetylene gas.
“A company performing any work on a zone certified motor is required to be specially certified for this,” said Craig Smorenburg, M&C’s Works Executive.
“As we are not certified for it ourselves, we partnered with a local OEM that has this certification and they performed the work under our supervision and in close consultation with us, the client and an independent zone certification authority.”
In addition to overseeing and quality-managing all the work done, M&C’s engineering team assigned to the project was required at the client’s request to recalculate the modified winding and core design for the stator.
“A complicating factor was that a new specification for motors of this type had been introduced recently, which necessitated having to obtain guidance from the inspection authority to ensure that the new spec was properly adhered to,” Craig pointed out.
The work performed by the zone certified OEM consisted of manufacturing a new stator core and coils in accordance with the applicable voltage and zone certification requirements and performing the rewind as designed by M&C and the OEM.
It was the first stator core rewind for a zone certified compressor drive train motor to be performed in South Africa.
The work culminated in a successful test run of the repaired and reassembled motor in M&C’s Cleveland plant at the end of February this year.
This again demonstrates M&C’s design, engineering and test capability and their flexibility to partner with various OEM’s to assist customers in providing the best possible quality solution.
