Kollmorgen has long supported motion systems used in explosive atmospheres and hazardous locations, including the popular Goldline EB servo motors. With the introduction of the new AKME Servo Motor Series, customers are now asking: What are the differences and which motor should I choose?”
While we can’t make the final choice for you, this high-level overview highlights the different types of protection each product line offers and the applications they’re best suited for, based on their certification markings found on the nameplate.
First things first: What makes a motor safe for hazardous locations?
Motors for use in hazardous locations must be engineered to prevent the ignition of potentially explosive atmospheres. Typical applications include mining, oil and natural gas refining, flour mills, grain elevators, textile mills, industrial paint booths, and other environments subject to hazardous atmospheres where ignitable gases, vapors or dusts may be present.
To meet these requirements, explosion-proof motors use a variety of protection features. These may include motor enclosures capable of withstanding an internal explosion, flame paths that prevent any internal flame or spark from reaching the outside environment, or encapsulation and IP-rated sealing approaches that keep flammable gases and dust away from electrical components. All are designed to make sure surface temperatures and internal energy levels never become hot enough to ignite hazardous materials.
What are hazardous location certifications?
Equipment used in potentially explosive atmospheres must be certified for use under the standards that apply in the regions where the equipment will be operated. These certifications are based on rigorous testing performed by recognized third-party certification bodies. Kollmorgen offers HazLoc products certified to key global standards, including:
- IECEx – An international certification system for equipment used in explosive atmospheres, recognized in most regions of the world, but not directly accepted in the United States or Canada.
- ATEX – A mandatory certification for hazardous locations in the European Union, the European Economic Area and the United Kingdom; also recognized (but not mandatory) in several other regions.
- UL – The North American standards for hazardous location equipment, covering both Zone and Division systems.
These are primary certifications for OEMs that want to deliver HazLoc equipment to markets around the world.
What are ATEX certification markings?
Certified hazardous location products include markings on the nameplate that indicate where and how the product may be safely used.
In this article, we’ll focus on ATEX markings, which provide a good overall guide and basis of comparison between Goldline EB and AKME servo motors.
ATEX Markings for AKME Series
II 3G Ex ec mc IIC T4 Gc
II 3D Ex tc IIIC T130°C Dc
ATEX Markings Goldline EB Series
What ATEX markings mean for motor choice
It’s beyond the scope of this article to define the meaning of each ATEX marking. Please consult an expert before specifying a Kollmorgen product for use in hazardous locations. That said, the similarities and differences between Goldline EB and AKME servo motors can all be gleaned from these markings. Let’s explore how these two HazLoc motors compare based on their individual markings and certifications.
- Both products are in the II equipment group, which means the equipment is suitable for use in surface-level environments other than mines susceptible to methane gas.
- The third-party certification body is different between products.
- AKME Series is certified by TÜV SÜD Product Service GmbH (0123).
- Goldline EB Series is certified by the Electrical Testing Laboratories (ETL) and Laboratoire Central des Industries Électriques (LCIE), now known as LCIE Bureau Veritas (0081).
- Both certification bodies are highly respected in the field of electrical equipment testing, particularly for equipment used in explosive atmospheres.
- AKME Series is Kollmorgen’s newest ATEX-certified brushless servo motors for hazardous locations.
- AKME motors can be used in environments (other than coal mines) where explosive gases, vapors or ignitable dusts are unlikely to occur, or they only occur infrequently and for a short period.
- Goldline EB motors can be used in hazardous locations where explosive gases exist continuously or are present for long periods of time.
- The equipment protection level (EPL) differs between products.
- ATEX uses a Zone system to characterize the likelihood of electrical equipment becoming a source of ignition.
- For gases, Zone 1 indicates a likely to occur risk and Zone 2 indicates an infrequent risk of explosive material being present.
- For dusts, Zone 21 indicates a likely to occur risk and Zone 22 indicates an infrequent risk of an ignitable powder or dust being present.
- AKME motors are rated for use in explosive atmospheres in Zones 2 and 22 environments, where gas or dust is not normally present in ignitable quantities but may occur for short periods (3G, 3D & Gc, Dc).
- Goldline EB motors are rated for Zone 1 environments, where there is a high risk of explosive gases or vapors (2G & Gb). Equipment suitable for Zone 1 can also be used in Zone 2.
- ATEX uses a Zone system to characterize the likelihood of electrical equipment becoming a source of ignition.
- The products are appropriate for use in different gas environments.
- AKME motors are designed for infrequent exposure to the most explosive gas atmospheres, such as hydrogen or acetylene (IIC). Equipment suitable for IIC environments can also be used in less-easily ignitable IIA and IIB environments.
- Goldline EB motors are suitable for use near gases that are in the midrange of explosive potential, for example, ethylene, diethyl ether and ethanol (IIB). It can also be used in IIA environments, which are the least hazardous category of flammable gases and vapors.
- The protection type differs. Various equipment design methods can be used to achieve protection in explosive atmospheres.
- AKME Series protection for explosive gas atmospheres includes Increased Safety (Ex ec) and Encapsulation (Ex mc) methods. Increased Safety means that the enclosure is designed to prevent the occurrence of arcs, sparks and high temperatures that could ignite. Encapsulation means that electrical components are cast in a compound that separates potential sources of ignition from the explosive atmosphere.
- AKME Series protection for explosive dust atmospheres includes Protection by Enclosure method (Ex tc), which is designed to prevent dust ingress and limit surface temperatures to prevent ignition of dust layers or clouds.
- Goldline EB Series protection for explosive gas atmospheres includes Flameproof and Explosion-Proof methods (Ex d). Also, robust housing can withstand an internal explosion and flame paths that allow explosion gases to escape while cooling them sufficiently to prevent ignition of the external atmosphere.
- The temperature classes differ. If the surface temperature of a motor exceeds the ignition temperature of a flammable gas or vapor, spontaneous combustion can result. HazLoc equipment must be designed to prevent these dangerous temperatures. The lower, the better. Always check the temperature class of your equipment against the auto-ignition temperature of any hazardous gas it may be exposed to.
- AKME motors are limited to a surface temperature of ≤ 135ºC (temperature class T4) for gas environments and ≤ 130ºC for dust environments.
- Goldline EB motors are limited to a surface temperature of ≤ 200ºC (temperature class T3).
- The ambient temperatures differ. This specification is not reflected in the ATEX markings but does indicate the range of environments these motors can be used in with optimal performance, longevity and safety.
- AKME servo motors are suitable for ambient temperatures ranging from 5ºC to 40 ºC.
- Goldline EB servo motors are suitable for ambient temperatures ranging from –40ºC to 40ºC.
- AKME Series applications: Built on the proven AKM servo motor platform, Kollmorgen’s new AKME motors bring unsurpassed torque density, compactness, mounting options, feedback versatility and value to Zone 2 and Zone 22 locations in these applications:
- Pharmaceutical production
- Food processing
- Grain elevators
- Industrial paint booths
- Metallurgical coating
- Waste-processing plants
- Petrochemical plants
- Textile mills
- Many other industrial settings
- Goldline EB Series applications: Goldline explosion-proof servo motors have been proven in a range of industries, particularly in Zone 1 and Zone 2 locations in these applications:
- Oil and natural gas (O&G) refining
- Top side O&G work environments
- Automated pipe-racking
- Industrial paint booths
- Petrochemical plants
- Tank interior cleaning applications
How to ensure safety first
Kollmorgen takes industrial safety seriously, and we know you do too. We’ve given you an overview of the features, capabilities and applications of the Goldline EB and the new AKME servo motor series for hazardous environments. But you should never feel the need to make such an important decision without any support.
We’re always here to help. Reach out to a Kollmorgen engineer to discuss your particular application requirements, learn more about all of our explosion-proof offerings, and make a confident choice for safety.
