Start-Up Procedure - International comfort products CAC075 Installation Instructions Manual

Installation Instructions
Start- -Up Procedure
Start- -up Procedure
1. Close electrical disconnects to energize system.
2. Energize crankcase heater on units so equipped.
3. Set Thermostat selector switch to OFF.
4. Set room thermostat at desired temperature. Be sure
setpoint is below indoor ambient temperature for cooling
and above indoor ambient for heating.
5. Set the system switch of the thermostat on COOL and
fan switch for continuous operation or AUTO, as desired.
Operate unit for 15--20 minutes, then check the system re-
frigerant charge if it was necessary to adjust.
6. After the refrigerant charge has been adjusted, the sys-
tem is now ready for continuous operation.
Final Refrigeration Charge Adjustment
Before any adjustment is made to the refrigerant charge, it
is imperative that the air flow characteristics of the indoor
blower be established.
When checking indoor air flow, it is important to remember
that the blower will deliver a higher quantity of air across a
dry coil versus a wet coil. Blower charts are calculated with
a dry coil.
Recommended air flow for installations of cooling units and
heat pumps is 350--450 CFM per ton (12,000 BTUH)
through a wet coil. Refer to indoor unit installation instruc-
tions for proper methods of determining air flow and blower
performance.
To Check System Refrigerant Charge
(Subcooling Method), Cooling Only
1. Attach an accurate temperature sensing device to the
liquid line approximately 4" -- 6" away from the liquid line
service valve. The temperature sensing device should be
clamped securely to the liquid line, on a horizontal plane
(between 9 & 3 O'clock) and insulated. Record the liquid
line temperature.
2. Measure and record the liquid line refrigeration pres-
sure. (Measure at the liquid line service valve gauge port.)
Using Temperature / Pressure Chart convert this pressure
to the saturation refrigerant temperature. The difference
between actual and saturated temperatures is the amount
of subcooling.
8
Figure 7 - - Temperature / Pressure Chart R- -22
Deg. F PSIG
70 121.4
72 125.7
74 130
76 134.5
78 139
80 143.6
82 148.4
84 153.2
86 158.2
88 163.2
90 168.4
92 173.7
94 179.1
96 184.6
98 190.2
100 195.9
102 201.8
104 207.7
106 213.8
108 220
110 226.4
3. The unit is properly charged if the subcooling level is
within the acceptable range as recommended in Figure 7.
If the actual subcooling levels are higher than shown, the
system is most likely over--charged, and charge should be
removed. Remove charge, and recalculate subcooling val-
ues. Continue adjusting charge until the actual subcooling
matches the recommended values.
If the actual subcooling levels are lower than shown, the
system is most likely under--charged, and charge should
be added. Add charge in 4 to 6 ounce increments, and re-
calculate subcooling values. Continue adjusting charge
until the actual subcooling level matches the recom-
mended values.
NOTE: Each time that charge is added or removed from
the system, allow the system to run approximately 15 min-
utes before pressure and temperature readings are taken
and subcooling calculations made.
Split System Condensers
Deg. F PSIG
112 232.7
114 239.3
116 246.1
118 252.9
120 259.9
122 267
124 274.2
126 281.6
128 289.1
130 296.8
132 304.6
134 312.5
136 320.6
138 328.8
140 337.3
142 345.8
144 354.5
146 363.3
148 372.3
150 381.5
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