only once per 7 days during normal operation. Provide tanks with a valved
cold water line and, if necessary, a valved hot water fill line with
suitable air gap. Provide tanks with device to indicate quantity of
solution in the tank. Provide electric mixing device with tank.
2.8.3
Valve Injection Assemblies
Provide for each feed pump. Construct of bronze or material suitable for
chemicals being used and install in condenser water line common to all
pumps. Injection fittings shall have male pipe threads. Assemblies shall
include shut-off valve and check valve provided close to condenser water
line.
2.8.4
Bleed-Off Solenoid Valves
Provide in bleed-off line. Valves shall normally be in closed position and
be opened by a 120-volt waterproof solenoid coil. Connect bleed-off line
to condenser water line and include a gate valve ahead of solenoid valve.
Extend a discharge line from solenoid valves to sewer drain.
2.8.5
Water Meters
Provide with electric contacting register, and remote accumulative counter
and installed in make-up water line near cooling tower. Meters shall be
standard product used in water treatment.
2.8.6
Timers
Automatic reset, adjustable type, and electrically operated. House in
metal NEMA type cabinet with a hinged front. Timers shall be suitable for
120 volt current.
2.8.7
Conductivity Controllers
Controllers shall measure total dissolved solids in system water by
conductivity. Conductivity sensors shall consist of epoxy insulated carbon
electrodes and shall not require platinizing. Controllers shall have a
meter with a visual readout, set point adjustment with a range between 200
micromhos/cm and 4000 micromhos/cm and a red pilot light indicating water
conductivity above set point. Units shall operate from a 120-volt power
source.
2.8.8
Control Panels
Provide a factory-wired, NEMA 12, control panel for each system. Construct
of steel with hinged door and lock, and suitable for surface mounting.
Pre-wire controls to numbered terminal strips. Provide laminated plastic
nameplates identifying the switch function. Include the following with the
panel:
a.
Main power switch and indicating lamp;
b.
MAN-OFF-AUTO selector switch;
c.
Indicating lamp for bleed-off valve;
d.
120 Volt, heavy-duty, grounded duplex receptacle;
e.
Conductivity controller;
SECTION 15601N
Page 39
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