035-16734-000
560.20-N1Y
Unitary Products Group
21
ACCESSORY WIRING
If the unit includes an electric heat accessory, separate power
wiring must be provided. Refer to electric heat instruction,
Form 550.13-N10.1U, for additional installation instructions.
Refer to Figure 15 and 16 for field wiring diagrams. Refer to
Table 17 to size the disconnect switch, the power wiring and
the fuses.
NOTE:Three phase motor rotations may be incorrect when
unit is first started. Reverse phase (leads L1 and L2) at
blower motor contactor to obtain correct rotation.
WATER REGULATING VALVES
Water regulating valves provide control of quantity of con-
denser water supplied to the unit under varying load condi-
tions by sensing compressor discharge pressure. This
feature is required in some areas where water conservation is
mandated.
Water regulating valves are shipped separately for field
installation.
Accessory kits 1WR0413, 1WR0402, and 1WR0403 are
used on the CED060, CED090 and CED120, and CED180
respectively.
Installation of water control valves is accomplished by remov-
ing front panel of condenser section, breaking water line
unions to condenser coils and removing water inlet piping.
Factory installed nipples are removed and replaced with the
nipples and water valve furnished for each condenser, unit is
repiped and capillary is attached to proper discharge line.
Valves are designed to operate between 25 and 150 psig. A
water pressure-reducing valve must be installed in condenser
water inlet line if pressure exceeds 150 psig.
COOLING TOWER
Where water costs are high, or water is not plentiful, an out-
door or indoor forced or induced draft-cooling tower is recom-
mend for condenser water.
Typical piping and wiring arrangements for installing one or
more units with pump and cooling tower as shown in Figures
17, 18 and 19.
1.
Figure 17 illustrates the piping including a bleed-off valve
and strainer in the suction line to the pump. The bleed-
off is needed to keep the concentration of salts down,
especially in areas having hard water.
The by-pass is used to permit circulation of a larger
quantity of water over the tower than through the con-
denser. This allows the tower to operate at greater effi-
ciency without suffering the pressure drip through the
condenser.
2.
Figure 18 shows the suggested wiring arrangement nec-
essary to interconnect the units pump and tower fan
motor. The entire system starts and stops automatically
3.
Figure 19 shows an alternate wiring arrangement. Its
room thermostat individually controls each unit. The
conditioner control circuit is energized by the pump
motor also starts the tower fan. After the pump is started
annually it will continue to operate until the stop button is
pushed. This arrangement is suggested where there will
be a long run of condenser water piping exposed so that
it might be heated excessively during the off periods with
automatic operation.
In each case, the wiring is such that there is water circulation
through the condenser when units are running.
Cooling towers must be selected for the specific conditions of
each application. Local representatives of cooling tower
manufacturers will assist in the selection of proper size tower
for each CED installation.
FIGURE 14 : ELECTRICAL CONTROL BOX
(CED090 SHOWN)
POWER WIRING
KNOCKOUTS
TERMINAL
BLOCK
(1TB)
TERMINAL
BLOCK
(2TB)
CONTROL BOX
