Rockwell Automation and ACTOM Electrical Machines collaboration results in ‘oil and gas’ hazardous area certification

25 September, 2015

Technical lowdown

As a subset of a larger project, five Allen-Bradley PowerFlex 7000 Medium Voltage AC Variable Speed Drives by Rockwell Automation and five ACTOM motors which will be used by Engen Petroleum’s Greenfields project to control Flowserve’s 1320 m³/h centrifugal pumps, facilitating the movement of product from Engen’s Island View facilities to Transnet’s NMPP Island View West site. Rockwell Automation’s PowerFlex 7000 are fitted with an 11 kV to 6.6 kV integral transformer to power ACTOM’s 650 kW, 6600 V, 4 pole motor situated in the hazardous area.

VSD and motor combination test

The VSD and motor combination test was conducted to determine the maximum surface temperature of the ACTOM Electrical Machines motor in accordance with SANS 60079-0: 2012 Ed 5 Clause 26.5.1.3 and Annex E, which included the monitoring of the motor winding temperature; ambient temperature; DE & NDE bearing temperatures; and motor supply voltage, current and rpm. The combination test was conducted at the motors maximum duty point for 8 continuous hours.

Meeting the requirements

Explolabs found that the drive and motor combination complied with the requirements set out in the standards and certified the installation for ‘Zone 2’ (‘Gas: Surface’) application, i.e. as the ‘location’ while the ‘environment’ is listed as ‘Group IIA and IIB’. ‘Frequency’ is listed as ‘abnormal’ as could occur under normal operation.

“Considering the criticality of this project and the stringent Engen specification meant we needed to supply a reliable solution that conformed to all the requirements of the various stakeholders,” said Henry Craukamp, ETO sales manager – Southern Europe and Africa.

Compatibility

“The test results prove the compatibility between Rockwell Automation drives and ACTOM’s motors, one of the reasons we entered into our co-operation agreement in 2013.” This agreement is to supply Rockwell Automation and ACTOM customers with appropriately paired variable speed drives and motor products.

The now Exn-certified VSD and motor combination was delivered to-site and the installation completed. The Rockwell Automation commissioning team is on stand-by to begin on-site commissioning as soon as Engen completes the remainder of the installation.

No temperature effect

“Rockwell Automation is extremely pleased with the outcome as it verifies that our VSDs has no temperature effect on the motor whatsoever. The tests further prove that our VSDs and ACTOM’s motors are compatible in one of the harshest environments. We will continue the certification process with our Low Voltage PowerFlex 755 series VSDs and ACTOM’s Low Voltage Motors,” Craukamp concluded. He adds that Engen Petroleum indicated it was “extremely satisfied with the result”.

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