Product category:
Industrial Motors
News Release from: WEG Electric Motors (UK) | Subject: W21 Line of high-efficiency motors
Edited by the Engineeringtalk Editorial
Team on 16 March 2007
Motors adopt new insulation
Insulating materials using a laminate of Nomex offer a high thermal classification (220C), high mechanical strength, outstanding electrical qualities and superior thermal resistance.
WEG's commitment to ever-higher levels of quality, performance and reliability from its electric motors is being underlined with the adoption of DuPont Nomex for phase and slot insulation in the company's W21 line of high efficiency motors Insulating materials using a laminate of Nomex (also known as NMN) offer a high thermal classification (220C), high mechanical strength, outstanding electrical qualities and superior thermal resistance
This article was originally published on Engineeringtalk on 1 Aug 2008 at 8.00am (UK)
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The adoption of NMN is in keeping with WEG's policy of always incorporating the latest technology into its manufacturing processes to produce products that conform to the highest and most demanding total quality control standards required by customers.
In this case the technology objective was to develop a range of high efficiency motors with higher thermal protection.
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According to Jose Reinaldo Cardoso, Material Development Analyst of WEG Industrias Motors Division, this is exactly what has been achieved with the adoption of Nomex laminate insulation.
"NMN supports a thermal stress three times higher than DMD, the material that we used previously".
"The polyester film inside the laminate ensures a high di-electric strength and Nomex, in addition to its excellent thermal resistance, has good saturability and impregnation properties with the resin and varnishes that are used".
"This allows us to reduce the air voids inside the insulation material that could lead to premature failures".
"In addition, should the polyester component in a NMN laminate fail because of overheating, the Nomex layers remain intact and continue to act as a physical barrier and electrical insulation material, which prevents total failure of the system".
"What all this means for our customers is more reliable and safer machines, especially since there is an extra margin of safety in cases where equipment is not operated correctly".
The use of Nomex in WEG's W21 Line of high-efficiency motors is part of an overall design initiative that also includes impregnation of the motor windings with higher insulation Class "H" varnish.
The result of this combination is a state of the art insulation system that withstands the voltage spikes commonly encountered with inverter use.
In addition, bearing protection against EDM (electrical discharge machining), which can cause motor failure, is offered as an option on W21 Line motors with frame sizes of 225 and above.
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