**************************************************************************
Seismic requirements shall be as specified in Sections 13080 SEISMIC
PROTECTION FOR MISCELLANEOUS EQUIPMENT, 15070A SEISMIC PROTECTION FOR
MECHANICAL EQUIPMENT and 16070A SEISMIC PROTECTION FOR ELECTRICAL EQUIPMENT
[as indicated]. ATS shall be suitable for prolonged performance under
following service conditions:
a.
Altitude:
[_____] m feet above mean sea level.
b.
[_____] percent maximum, continuous.
c.
Temperature:
Minus [_____] to [_____] degrees C F.
d.
Seismic Parameters:
[_____].
PART 2
PRODUCTS
**************************************************************************
NOTE: Normally, switched poles should be limited to
three for three-phase, three- or four-wire systems.
Switching of neutral (fourth pole) should only be
considered where emergency/alternate power source is
a separately derived system; where ground potential
at the two voltage sources differs significantly; or
where NFPA 70 requires ground fault protection for
equipment.
Sizing of neutral bus, pole, contacts, and
terminations should consider harmonic currents.
Nonlinear loads such as switch mode power supplies,
electronic ballasts, personal computers, laser
printers, variable frequency motor drives, static
uninterruptible power supplies, and other equipment
described in IEEE 519 and 1100 will produce harmonic
currents with high zero phase sequence components
which are additive in neutral circuit. Neutral
ampere rating may need to be higher than phase
contacts (200 percent is typical for 100% harmonic
load).
**************************************************************************
2.1
AUTOMATIC TRANSFER SWITCH (ATS)
**************************************************************************
NOTE: Calculate short-circuit current available at
ATS supply terminals. Caution: emergency source may
be capable of supplying larger amount of
short-circuit current. Ampere interrupting capacity
(AIC) rating of circuit protective devices on ATS
supply side should equal or exceed available
short-circuit current. Since ATS WCR should be
equal to or greater than AIC rating of upstream
circuit protective devices, care should be used in
determining available AIC to avoid high costs of
over-rated ATS. WCRs listed in UL 1008 should be
used when fault currents are less than WCR listed.
However, in no case should WCR be less than 10,000
amperes.
SECTION 16410A
Page 8
Previous Page
