Electric Motor Control Basics - Book - Page 81
NEMA vs IEC Motor Controls
Comparing NEMA vs IEC
When choosing between NEMA vs IEC, there are some key differences to note.
• IEC-rated equipment is less expensive than NEMA-rated ones.
• NEMA ratings are more versatile, designed to apply to many different applications.
• NEMA caters to large-sized devices in North American Markets only.
• IEC ratings are for more compact devices in the global market.
• IEC ratings react faster to overloads while NEMA ratings withstand short circuits.
• IEC devices are safe to the user, while NEMA devices require safety covers.
Despite these significant differences, there are still some common misunderstandings
that need to be debunked. One of them is concerning the NEMA starter. Although it
looks larger than the IEC starter, some people think it makes more robust devices.
In actuality, it merely looks more extensive because of its design. As a result, the wrong
IEC classification will be used instead of the accurate NEMA classification. This will lead
to blame on the IEC system when the rating fails to perform as expected.
In reality, the Underwriters Laboratories testing applies across the board for both IEC
and NEMA applications. In essence, the differences are not merely about the sizes or
cost-effectiveness. There’s a need to gain a deeper understanding of how each system
works.
Industrial Control
Basics:
Part 1, Contactors
Industrial Control
Basics: Part 2,
Overload Relays
Industrial Control
Basics: Part 3,
Starters
The Benefits of Type E/F
Motor Protection
Circuit Breakers
Basic Pump Control:
Three Phase DOL Starter
Control of an Electric Pump
Applying Motor Control
in a Wastewater
Application
NEMA vs IEC Motor
Controls
Understanding
IP Ratings
81
