Cut Sheet

Volume 10—Enclosed Control CA08100012E—November 2012 www.eaton.com V10-T17-7
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Technical Data and Specifications
NEMA Contactors and Starters
Electrical Life—AC-3 and AC-4 Utilization Categories
Life Load Curves
Eaton’s Freedom Series
NEMA contactors have been
designed and manufactured
for superior life performance
in any worldwide application.
All testing has been based on
requirements as found in
NEMA and UL standards and
conducted by Eaton. Actual
application life may vary
depending on environmental
conditions and application
duty cycle.
Utilization Categories
AC-1—Non-inductive or
slightly inductive loads, such
as resistance furnaces and
heating.
AC-2—Starting of slip-ring
motors.
AC-3—Squirrel cage motors;
starting, switching off motors
during running.
AC-4—Squirrel cage motors;
starting, plugging, inching or
jogging.
Note: AC-3 tests are conducted at
rated device currents and AC-4
tests are conducted at six times
rated device currents. All tests
have been run at 460V, 60 Hz.
Contactor Choice
●
Decide what utilization
category your application is
and choose the appropriate
curve
●
Locate the intersection of
the life-load curve of the
appropriate contactor with
the applications operational
current (I
e
), as found on the
horizontal axis
●
Read the estimated
contact life along the
vertical axis in number of
operational cycles
AC-3 and AC-4 Utilization Categories
NEMA AC-3 Load Life, Sizes 00–5, 480V 60 Hz
100,000,000
10,000,000
1,000,000
100,000
9
110
Break Amperes
100 1000
18 27 45 90 135 270
Size 00
Size 0 Size 1
Size 2 Size 3
Size 4 Size 5
Operations Operations
NEMA AC-4 Load Life, Sizes 00–5, 480V 60 Hz
100,000,000
Size 00
Size 0 Size 1 Size 2 Size 3 Size 4
Size 5
10,000,000
1,000,000
100,000
10,000
10854
110
Break Amperes
100 1000 10,000
153 270 540 822 1620