JOHNSON CONTROLS
34
FORM 160.81-NOM1
ISSUE DATE: 10/3/2020
SECTION 1 – INSTALLATION
Stop Valves
Stop valves may be provided (by others) in the evapo-
rator and condenser water piping, adjacent to the unit
to ease maintenance. Pressure taps should be provided
(by others) in the piping as close to the unit as possible,
to aid in obtaining operating checks.
Flow Switches (Field Installed)
A flow switch or pressure differential control in the
chilled water line(s), adjacent to the unit, is an ac-
cessory which can be provided by Johnson Controls
for connection to the control center. If a flow switch
is used, it must be directly in series with the unit and
sensing only water flow through the unit. The differ-
ential switch must sense pressure drop across the unit.
Drain and Vent Valves
Drain and vent valves (by others) should be installed
in the connections provided in the evaporator and con-
denser liquid heads. These connections may be piped
to drain if desired.
Checking Piping Circuits and Venting Air
After the water piping is completed, but before any wa-
terbox insulation is applied, tighten and torque the nuts
on the liquid head flanges (to maintain between 30 and
60 ft. lbs. / 41 and 81 mm). Gasket shrinkage and han-
dling during transit may cause nuts to loosen. If water
pressure is applied before this is done, the gaskets may
be damaged and have to be replaced. Fill the chilled
and condenser water circuits, operate the pumps manu-
ally and carefully check the evaporator and condenser
water heads and piping for leaks. Repair leaks as nec-
essary.
Before initial operation of the unit both water circuits
should be thoroughly vented of all air at the high points.
FIGURE 15 -
COOLING TOWER PIPING WITH 3 PORT BY-PASS VALVE
Cooling
Tower
Condenser
Controller
Gauges
Alternate Bypass
Sump w/ Strainer
Roof
3-Way Diverting Valve
LD10024
