JOHNSON CONTROLS
79
SECTION 2 – INSTALLATION
FORM 145.05-NOM7
ISSUE DATE: 10/31/2019
6. A strainer to remove foreign matter from the wa-
ter before it enters the pump. It should be placed
far enough upstream to prevent cavitations at the
pump inlet (consult pump manufacturer for rec
-
ommendations). Using a strainer prolongs pump
life and helps maintain system performance.
7.
A strainer with a #30 mesh or finer to remove
foreign matter from the water before it enters the
unit.
8. Size piping to minimize system pressure drop.
9. All piping must be supported independent of the
unit.
10. To aid in service the unit should have a union in
the water inlet and outlet water lines.
Condenser Connections
)
1. Condenser water connections enter the unit from
the top.
2. All condensers are factory piped for a common
condenser water supply and common condenser
water return connection.
3. The condenser water supply and return lines are
manufactured to allow the use of Victaulic cou-
plings to connect the field piping to the unit. The
connections between the unit and the field piping
can also be made with a sweat connection. This
can be accomplished by cutting off the grooved
section of the factory supplied copper tube, in-
tended for the Vitaulic coupling, and using a cop-
per coupling to sweat the field piping to the unit.
On units ordered with the limited access option it
is recommended that Vitaulic couplings be used
for the connection of the field piping to the unit.
Access to these joints is achieved by removing the
access panel between the blower and evaporator
coil compartment and removing the access panel
on the left hand side of the evaporator coil com-
partment. This restricted access makes it difficult
to make a quality sweat joint.
4.
Reference the Unit Dimension drawings (
25 on page 45 through Figure 43 on page 73
for the exact location of the supply and return wa-
ter line connections.
SUPPLY
CONNECTION
SUPPLY
CONNECTION
RETURN
CONNECTION
RETURN
CONNECTION
LIMITED ACCESS
PANEL
LIMITED ACCESS
PANEL
FIGURE 56 -
CONDENSER CONNECTIONS
5. Units with factory mounted waterside economiz-
er should not require head pressure control. The
economizer typically elevates the water tempera-
ture by 5.0–10.0°F before entering the condenser,
allowing suitable condenser water temperatures
whenever the tower supply temperature is 50.0°F
or higher.
6. Head pressure control must be provided if entering
condenser water temperatures go below 45.0°F.
a. Fan cycling and/or modulating discharge
dampers on the cooling tower, or a three-way
bypass around the tower are often used to
maintain condenser water temperature. Cool-
ing tower control to maintain the temperature
greater than 45.0°F is generally more cost ef-
fective if multiple units are in the loop.
b. If valves are installed on the individual units,
a single water regulating valve controlled by
the lowest discharge pressure of the operat-
ing compressors control head pressure.