NEMA Contactors and Starters - Tri-State Electrical Supply
NEMA Contactors and Starters - Tri-State Electrical Supply
NEMA Contactors and Starters - Tri-State Electrical Supply
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33.1<br />
<strong>NEMA</strong> <strong>Contactors</strong> <strong>and</strong> <strong>Starters</strong><br />
Freedom Series<br />
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<strong>Electrical</strong> Life—AC-3 <strong>and</strong> AC-4 Utilization Categories<br />
Life Load Curves<br />
Eaton’s Freedom Series<br />
<strong>NEMA</strong> contactors have been<br />
designed <strong>and</strong> manufactured<br />
for superior life performance<br />
in any worldwide application.<br />
All testing has been based on<br />
requirements as found in<br />
<strong>NEMA</strong> <strong>and</strong> UL st<strong>and</strong>ards <strong>and</strong><br />
conducted by Eaton. Actual<br />
application life may vary<br />
depending on environmental<br />
conditions <strong>and</strong> application<br />
duty cycle.<br />
AC-3 <strong>and</strong> AC-4 Utilization Categories<br />
Operations Operations<br />
100,000,000<br />
10,000,000<br />
1,000,000<br />
100,000<br />
100,000,000<br />
10,000,000<br />
1,000,000<br />
100,000<br />
9<br />
1 10<br />
Utilization Categories<br />
The International<br />
Electrotechnical Commission<br />
(IEC) has developed utilization<br />
categories for contactors <strong>and</strong><br />
auxiliary contacts. The IEC<br />
utilization categories are used<br />
to define the type of electrical<br />
load for estimating electrical<br />
life, <strong>and</strong> do not imply the<br />
devices are IEC rated.<br />
AC-1—Non-inductive or<br />
slightly inductive loads,<br />
such as resistance furnaces<br />
<strong>and</strong> heating.<br />
Size 00<br />
Size 0<br />
Size 1<br />
Size 2<br />
Size 3<br />
Break Amperes<br />
<strong>NEMA</strong> AC-3 Load Life, Sizes 00–5, 480V 60 Hz<br />
Size 4<br />
AC-2—Starting of slip-ring<br />
motors.<br />
AC-3—Squirrel cage motors;<br />
starting, switching off motors<br />
during running.<br />
AC-4—Squirrel cage motors;<br />
starting, plugging, inching<br />
or jogging.<br />
Note: AC-3 tests are conducted<br />
at rated device currents <strong>and</strong> AC-4<br />
tests are conducted at six times<br />
rated device currents. All tests<br />
have been run at 460V, 60 Hz.<br />
Size 5<br />
18 27 45 90 135 270<br />
100 1000<br />
Size 00<br />
Size 0<br />
Size 1<br />
10,000<br />
54 108 153 270 540 822 1620<br />
1 10<br />
100 1000 10,000<br />
Break Amperes<br />
<strong>NEMA</strong> AC-4 Load Life, Sizes 00–5, 480V 60 Hz<br />
Size 2<br />
Size 3<br />
Size 4<br />
Size 5<br />
Contactor Choice<br />
●<br />
Decide what utilization<br />
category your application<br />
is <strong>and</strong> choose the<br />
appropriate curve<br />
●<br />
Locate the intersection of<br />
the life-load curve of the<br />
appropriate contactor with<br />
the applications operational<br />
current (I e ), as found on<br />
the horizontal axis<br />
● Read the estimated<br />
contact life along the<br />
vertical axis in number<br />
of operational cycles<br />
38 Control Products Catalog CA08102001E—August 2010 www.eaton.com
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