Due to the processes involved, many industries such as oil and gas, chemical and petrol-chemical, energy or pharmaceutical industries may encounter flammable substances (gas, vapour, mist, liquid, dust, small fibres) and could involve an explosive atmosphere. Where dynamic performance or compact dimensions are required, servo motor technology provides the best solution. Parker has developed specific ATEX Permanent Magnet AC (PMAC) motors where compact dimensions and dynamic response with torque, speed or positioning control are required. These 10-pole servomotors are up to five times more compact than comparable asynchronous motors.
Parker’s EX series is also ideal for applications that include: filling machines in the packaging sector, oil and gas valve actuators, automotive paint shop robots and feed mills in the food sector.
An explosive atmosphere is a mixture of air and flammable substances such as gas, vapour or dust under atmospheric conditions that can explode, where for an explosion to occur, three circumstances must be fulfilled: the presence of fuel, oxygen and a source of ignition. Ignition sources, such as flames, electric arcs and sparks, ultrasound, chemicals or electromagnetic radiation have the potential to cause an explosion in certain circumstances.
Parker EX servomotors, characterized by excellent motion quality, great acceleration/deceleration capabilities and high torque output over a wide speed range, are specifically designed to follow the European ATEX regulation for explosive atmospheres, based on the following European directives:
1- 1999/92/EC: Under the end-user responsibility, 1- 1999/92/EC regulates worker safety and explosive zone classification. EX servomotors are designed and certified to be safe under normal operating conditions both in a place where an explosive atmosphere is likely to occur only occasionally (between 10 to 1000h/y) as well as in a place where it can occur for a very short period (>10/y) (see left-hand side of the chart below).
2- 2014/34/EU: Under the supplier's responsibility, 2- 2014/34/EU regulates the device's design compliance for operation in explosive environments. EX servomotors are designed to guarantee safety with a high level of protection, giving single fault tolerance. (see right-hand side of the chart below).
EX servomotors are ATEX compliant for operation in surface industries (Equipment Group II) and in accordance with given levels of flammability for substances present in the atmosphere, such as propane (IIA), ethylene (IIB), Hydrogen & Acetylene (IIC) regarding gas reference and combustible flying (IIA), non-conductive dust (IIB) and conductive dust (IIC) regarding dust reference. While the temperature classification is T4 (135°C).
In 2016, Parker extended the EX servo motor compliance to the IECEx standard as well as to the regional Kosha certification for the Korean market. More recently, EX servo motors have been CCC certified to guarantee compliance with Chinese legislation, where CCC certification is mandatory for explosion proof products (Ex products). Apart from the specific nameplate, CCC motors have the same construction as IECEx motors. They are intended for use in the same areas (gas or dust) and have the same degree of safety.
As an option, Parker offers a version of the EX series that is certified UL for the North American market in accordance with the UL674 standard. Importantly, Parker’s extensive portfolio of ATEX-rated motors, gearheads and actuators ensures the right combination of application-compatible products can be selected every time. Various winding variants and numerous options are available to offer maximum flexibility.
The precision helical gearing design of the GXA gearbox series associated with the powerful Parker ATEX servomotors range offers smooth and quiet operation for the most demanding high-performance applications. Finally, our well-known ETH electro cylinder range for explosive atmospheres are certified for use in explosive gas atmospheres (device group II, category 2G)
Want to know more about our motor series and international standards? View the slideshare presentation.
and Giulia Seri, product manager - electric motors, Electric Motion & Pneumatic Division, Parker Hannifin Corporation