ABB achieve Ex motor certification
ABB have achieved both stator and rotor component certification for their high-voltage modular and cast iron induction motors (up to 7,000kW), and rotor component certification for their low-voltage cast iron motors.
The accreditation proves that the company’s non-sparking (Ex nA) and increased safety (Ex e) motors meet the latest IEC and EN standards – IEC 60079-15:2005 and EN 60079-15:2005 for Ex nA; and IEC 60079-7:2006 and EN 60079-7:2007 for Ex e.
Achieving certification for their products ensures ABB customers benefit from reduced initial capital expenditure, lower operating costs and quicker starting, compared with uncertified motors that need special measures such as pre-start ventilation (purging), which means higher capacity air-compressors, piping and ventilation control units are required, thereby increasing capital expenditure. Uncertified motors also require purging every time the engine starts, increasing the time taken to get plant up and running.
More importantly, ABB’s certified motors offer proven safety. The latest IEC and EN standards specify criteria for risk assessment and gas environment tests for rotor and stator designs to ascertain that the motors are spark-free in all operational conditions.
Stator sparking, which consists of partial discharges at the winding surface due to high potential differences, tends to occur continuously when the motor is running. Typical causes include high voltage, inappropriate stress grading and degradation of the insulation due to aging, voltage transients, or dirt in the windings.
Rotor sparking takes place during starting and occurs between the rotor bars and rotor core, particularly in the vicinity of the first radial cooling ducts. It is generally caused by shaking of the rotor bars in the slots, which interrupts current flow between the bars and core.
The ABB motors achieved the following standards in the tests:
The accreditation proves that the company’s non-sparking (Ex nA) and increased safety (Ex e) motors meet the latest IEC and EN standards – IEC 60079-15:2005 and EN 60079-15:2005 for Ex nA; and IEC 60079-7:2006 and EN 60079-7:2007 for Ex e.
Achieving certification for their products ensures ABB customers benefit from reduced initial capital expenditure, lower operating costs and quicker starting, compared with uncertified motors that need special measures such as pre-start ventilation (purging), which means higher capacity air-compressors, piping and ventilation control units are required, thereby increasing capital expenditure. Uncertified motors also require purging every time the engine starts, increasing the time taken to get plant up and running.
More importantly, ABB’s certified motors offer proven safety. The latest IEC and EN standards specify criteria for risk assessment and gas environment tests for rotor and stator designs to ascertain that the motors are spark-free in all operational conditions.
Stator sparking, which consists of partial discharges at the winding surface due to high potential differences, tends to occur continuously when the motor is running. Typical causes include high voltage, inappropriate stress grading and degradation of the insulation due to aging, voltage transients, or dirt in the windings.
Rotor sparking takes place during starting and occurs between the rotor bars and rotor core, particularly in the vicinity of the first radial cooling ducts. It is generally caused by shaking of the rotor bars in the slots, which interrupts current flow between the bars and core.
The ABB motors achieved the following standards in the tests:
- All rotor tests passed (motors up to 15kW) with Group IIA, IIB and IIC gases.
- Stator tests passed up to 15kW with Group IIA and IIB gases.
- Stator tests passed up to 13.2kW with Group IIC gases, including hydrogen.
