for total system transfer and have the current and voltage ratings as
indicated. The rating of the switch shall be adequate for withstanding the
effects of the indicated RMS symmetrical fault current when protected by
the indicated overcurrent device without contact welding. The switch
operating mechanism shall be electrically operated from the source to which
it is transferring, shall have quick-make, quick-break, load break
contacts, and shall be mechanically held in both positions. [Switches
utilizing circuit breakers are not acceptable.] Non-fire pump service
transfer switches shall have manual operating means provided for
maintenance and servicing accessible only by opening the enclosure.
[Transfer switches for fire pump service shall have manual operating means
externally operable without opening the enclosure.] The manual operating
means shall affect the opening and closing of the switch contacts at the
same rate of speed as that caused by the automatic operation of the switch.
[Automatic transfer switches provided with by-pass/isolation switches
shall be mounted on a drawout mechanism so that the automatic transfer
switch can be removed from the enclosure.] [The switch enclosure shall
comply with UL 508, NEMA Type [1], [12],[____], and shall be equipped with
an equipment ground lug.]
[2.1.1
By-Pass/Isolation Switches
**************************************************************************
NOTE: Include by-pass/isolation switches only where
the nature of the loads make continuance of power
essential when the associated ATS switch is
disconnected for repairs, preventive maintenance, or
testing. Provide by-pass/isolation switches for
automatic transfer switches to be installed in
facilities complying with MIL-HDBK-1191, DOD Medical
and Dental treatment Facilities Design and
Construction Guide.
**************************************************************************
Include by-pass/isolation switches for the indicated automatic transfer
switches. Provide by-pass/isolation switches in accordance with UL 1008
that can be used to manually select an available power source to feed load
circuits and to permit total isolation of the automatic transfer switch.
The by-pass/isolation switch shall be rated for total system transfer and
have the same current rating, voltage rating, number of poles, and
withstand and closing rating as the associated automatic transfer switch.
]2.1.2
Automatic Transfer Switch Controls
[2.1.2.1
Controls for Utility-Generator Automatic Transfer Switch
**************************************************************************
NOTE: The following paragraph is intended for use
when the automatic transfer switch is to be used for
transferring loads to an emergency generator upon
loss of the normal (utility) source.
**************************************************************************
Provide all necessary controls to start the generator set upon loss of the
normal (utility) source, transfer the load to the generator set upon
reaching rated voltage and frequency, re-transfer the load when the normal
(utility) source returns, and stop the generator set.
The switch shall include the following control features.
SECTION 16410N
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