KS 3-2010
Page 11
Section 6
TEST PROCEDURES
6.1 General
The KS 3 Standards Publication is not intended, nor is it adequate, to verify proper electrical performance
of a switch that has been disassembled, modified, rebuilt, refurbished, or handled in any manner not
intended or authorized by the original switch manufacturer. The following non-destructive tests may be
used to verify specific operational characteristics of switches: mechanical operation test, insulation
resistance test, and individual pole resistance test (millivolt drop test).
6.2 Mechanical Operation Test
6.2.1 Purpose
To verify that the switch mechanism is operating freely.
6.2.2 Equipment
Appropriately rated continuity indicating device.
6.2.3 Procedure
WARNING—Follow all safety procedures described in Section 2.
6.2.3.1 After disconnecting and locking out all power, operate the switch ON and OFF 2 or 3 times. The
switch handle should operate smoothly without binding.
6.2.3.2 Using an ohmmeter or other indicating device, verify that all switch contacts are open when the
handle is in the OFF position and closed when the handle is in the ON position.
6.2.3.3 For switches that are provided with mechanical trip provisions (generally indicated by a test
button), operate the tripping means according to the manufacturer's instructions. With the
switch in the tripped position, verify that the contacts are open using an ohmmeter (or other
indicating device). Reset the switch according to the manufacturer's instructions and operate
the switch to the ON and OFF positions. Use an ohmmeter (or other indicating device) to verify
that all the contacts are closing and opening respectively.
6.2.4 Results
The switch must be repaired or replaced if:
a. The contacts are not open with the switch in the OFF position
b. The contacts are not closed with the switch in the ON position
c. The switch does not reset
d. The mechanical trip provisions (if provided) do not trip the switch
6.2.5 Reinstallation Procedure
For reinstallation or replacement of the switch and/or accessories, follow the safety installation
procedures given in 2.3.
© Copyright 2010 by the National Electrical Manufacturers Association.
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