b.
Sealed batteries: Provide batteries with leakproof, spillproof
electrolyte utilizing highly absorbent material to separate the
positive and negative plates. Battery jars shall be hermetically
sealed with welded seams. Batteries shall be maintenance-free and
shall not require water to be added. Capacity shall be calculated by
switchgear manufacturer and approved by Contracting Officer before
acceptance.
c.
Battery charger shall be full-wave rectifier type, utilizing silicon
semiconductor devices. Charger shall maintain a float charge of 2.15 V
per cell and an equalizing charge of 2.33 V per cell. An equalizing
charge timer shall be provided which operates automatically after an AC
power failure of 5 seconds or more. Timer shall be adjustable for any
time period up to 24 hours. Timer shall also be capable of being
actuated manually. Adjustable float and equalizing voltage
potentiometers shall be provided. Charger voltage shall be maintained
within plus or minus 1/2 percent from no load to full load with AC line
variations of plus or minus 10 percent and frequency variations of plus
1/2 inch scale and 2 percent accuracy of full scale shall be provided.
Output current shall be limited to 115 percent of rated output current,
even down to short circuit of the DC output terminals. Solid state
circuit shall have AC and DC transient voltage terminals. AC and DC
magnetic circuit breakers shall be provided. Circuit breakers shall
not be overloaded or actuated under any external circuit condition,
including recharge of a fully discharged battery and short circuit of
the output terminals. Charger shall be capable of continuous operation
at rated current at an ambient temperature of 40 degrees C. Output DC
current capacity shall match the requirements of the batteries provided.
d.
Secure battery rack such that it can not overturn or be disrupted by
lateral forces accompanying a seismic disturbance. Provide steel,
three-step racks, painted with two coats of acid resistant paint for
mounting batteries. Provide lead-plated copper inter-rack connectors
and cell numbers with each rack.
2.2.8
Metal-Enclosed Interrupter Switchgear Outgoing Section
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NOTE: This paragraph may also be used to specify
freestanding switchgear not directly connected to a
unit substation. This paragraph can not be used for
generator control switchgear. Specify Category A
requirements when switchgear area is subject to
access by the unsupervised general public. Category
B enclosures must be fence enclosed or in a locked
room.
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NOTE: To help determine whether metal-clad
switchgear or metal-enclosed interrupter switchgear
is more appropriate for a project, consider that the
primary applications for interrupter switchgear are
where there are no instantaneous relaying and where
switching is infrequent. Also interrupter
switchgear is significantly less costly than
metal-clad switchgear.
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SECTION 16361N
Page 31
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