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What is the rating of the number of switching operations of Square D, 100A, General Duty, F-Series Safety Switches? These ratings are also sometimes referred to as Endurance operations and Horsepower-overload operations.

Issue:
Product Design Features

Product Line:
General Duty Safety Switches

Environment: 
Mechanical Endurance

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.  For the endurance test, however, Square D F-Series Safety Switches exceed the UL and NEMA requirements by up to 3 times the total (see below table).
 
NUMBER OF OPERATIONS
Square D Safety Switches (F-series) 100A, General Duty:
Endurance test number of operations
Test Standards At rated load* No load Total (load + no load)
UL 6000 4000 10000
NEMA 6000 4000 10000
Square D 6000 24000 30000
* endurance test performed at switch rated load current
Horsepower test number of operations
Test Standards At rated HP**
UL 50
NEMA 50
Square D 50
** horsepower test - make/break motor inrush/locked rotor current at rated HP
Number of switching operations for other General Duty safety switches:
  • For 30-60A series E General Duty safety switches, see FA112144
  • For 30-60A series F General Duty safety switches, see FA99707
  • For 200A series F General Duty safety switches, see FA99735
  • For 400A series E General Duty safety switches, see FA99736
  • For 600A series E General Duty safety switches, see FA99737
  • For 800A series E General Duty safety switches, see FA99761
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