Electric Motor Control Basics - Book - Page 11
Industrial Control Basics: Part 1, Contactors
IEC vs NEMA
IEC
NEMA
Less expensive
More compact
Global market
Less versatile: IEC contactors are specific
application requirements
Finger safe
Faster reaction to overloads
More expensive
Larger design
North American market
More versatile: A NEMA contactor can cover
a broader range of applications
Safety covers required
Can handle short circuits better
People often mistakenly perceive NEMA contactors as more robust. In reality, this is
due to their design being oversized.
The following two tables detail how NEMA and IEC size contactors and starters.
NEMA Contactor and Starter Sizes
NEMA Size
Max. Continuous
Amperes
Max. HP
at 200 V AC
Max. HP
at 230 V AC
Max. HP at 480/575
V AC
00
9
1.5
1.5
2
0
18
3
3
5
1
27
7.5
7.5
10
2
45
10
15
25
3
90
25
35
50
4
135
40
50
100
5
270
75
100
200
6
540
150
200
400
7
810
–
300
600
8
1215
–
450
900
9
2250
–
800
1600
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
11
