mounting batteries. Provide reliable separation between cells and from
ground. Connect batteries to "float" on the exterior fire alarm reporting
and receiving system circuits.
2.7.4
Electronic Inverters
**************************************************************************
NOTE: Nickel-cadmium batteries should not be
specified over lead-calcium type unless some unusual
environmental or operational condition warrants the
additional cost of nickel-cadmium. For normal
installations, battery selection may be left as a
contractor's option. Ensure battery room or
location has adequate ventilation to keep hydrogen
concentrations below 3 percent.
**************************************************************************
Provide units capable of 115-volt 60-Hz ac output in alarm receiving
headquarters [and in each fire station] for operating alarm receiving,
alarm transmitting, recording and signalling devices, or components
requiring 115 Vac. Inverters shall be battery powered and arranged to
operate automatically in the event of loss of normal ac power. Provide
battery power supply from either the main alarm system standby battery or
from separate [sealed,] wet-cell, [lead-acid (lead antimony)] [or]
[lead-calcium] batteries and charger. Provide battery power supply to
sustain the connected devices under normal operating load for a minimum of
24 hours. If supplied from the main alarm system, provide alarm system
batteries to sustain connected loads for the full 24-hour period.
2.7.5
Transformers
**************************************************************************
NOTE: Detail transformers on drawings.
**************************************************************************
Provide isolation and step-down transformers for proper operation of the
various components of the system.
2.8
WIRING
Provide color coded wires and cables.
2.8.1
Wiring Within Buildings
**************************************************************************
NOTE: Type THW insulation can only be obtained in
large quantity. Use of this type insulation is not
recommended for small projects.
**************************************************************************
Provide in conduit or electrical metallic tubing, except wiring within
cabinets and other components of the system. Wiring for 120-volt circuits
shall be not less than No. [12] [_____] AWG. Wiring shall comply with NFPA
70 and NFPA 1221. Conductors shall be copper, Type [THW] or [THWN]
conforming to UL 83. Color code conductors. Distinctly color code
conductors used for the same functions. Use two different color codes for
each alarm circuit; one for each loop. Wiring color code shall remain
uniform throughout the circuit.
SECTION 13851N
Page 21
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