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What is the rating of the number of switching operations of Square D, 400A, Heavy Duty, E-Series Safety Switches? These ratings are also sometimes referred to as Endurance operations and Horsepower-overload operations.

Issue:
Product design feature

Product Line:
Heavy Duty Safety Switches

Environment:
Number of operations

Cause:
Application

Resolution:

For Safety Switches, the standard for design and testing of the number of switching operations is governed by UL98 and NEMA KS-1.There are two separate tests: (1) Endurance Test, and (2) Horsepower-overload test. The below table shows the minimum number of operations required (OFF to ON to OFF) by UL and NEMA, as well as the number of operations required by Square D.

NUMBER OF OPERATIONS
Square D Safety Switches (E-series)
400A, Heavy Duty
-------------------------Endurance test # of ops------------------. . . . . . . ----HP test # of ops
test stds.....rated Load*...... No-Load...... total (L + NL) . . . . . . . . . . . . . at rated HP**
UL...................1000..................5000.................6000 . . . . . . . . . . . . . . . . . . . . .10
NEMA............1500..................6000.................7500. . . . . . . . . . . . . . . . . . . . . 10
Square D.........1500..............6000................7500 . . . . . . . . . . . . . . . . . . . . 10
* endurance test done at switch rated Load current
** horsepower test - make/break motor inrush/locked rotor current at rated HP



CTA-ID : 2003391
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