Carrier 38AK007 - Manual (Page 5)

FIELD CONTROL WIRING — Install a Carrier-approved
accessory thermostat assembly according to installation in­
structions included with the accessory. Locate thermostat
assembly on a solid wall in the conditioned space to sense
average temperature in accordance with thermostat instal­
lation instructions.
Route thermostat cable or equivalent single leads of col­
ored wire from subbase terminals to low-voltage connec­
tions on unit (shown in Fig. 4) as described in Steps 1 through
3 below.
NOTE: For wire runs up to 50 ft, use no. 18 AWG (Amer­
ican Wire Gage) insulated wire (35 C minimum). For 50 to
75 ft, use no. 16 AWG insulated wire (35 C minimum).
For over 75 ft, use no. 14 AWG insulated wire (35 C min­
imum). All wire larger than no. 18 AWG cannot be directly
connected to the thermostat and will require a junction box
and splice at the thermostat.
1. Connect thermostat wires to screw terminals of low-
voltage connection board.
2. Pass the control wires through the hole provided in the
comer post.
3. Feed wire through the raceway built into the comer post
to the 24-v barrier located on the left side of the control
box. See Fig. 5. The raceway provides the UL required
clearance
wiring.
THERMOSTAT
between the high- and low-voltage
THERMOSTAT CONNECTIONS
FOR STANDARD UNIT
WIRING CONNECTIONS
UNIT CONNECTION
BOARD
Fig. 4 — Control Wiring Connections
HOLE IN
END PANEL
(HIDDEN)
START-UP
Preliminary Checks
1. Check that all internal wiring connections are tight and
that all barriers, covers, and panels are in place.
2. Field electrical power source must agree with unit name­
plate rating.
3. All service valves must be open.
Leak Test — Test entire refrigerant system by using soap
bubbles and/or an electronic leak detector.
Evacuate and Dehydrate — Evacuate and dehy­
drate entire refrigerant system by use of the methods de­
scribed in GTAC II, Module 4, System Dehydration.
Refrigerant Charge — Refer to GTAC II, Module 5,
Charging Recovery, Recycling and Reclamation.
Unit panels must be in place when unit is operating dur­
ing charging procedure.
Unit is shipped with holding charge only. Weigh in 7 lbs
R-22 to start unit.
NO CHARGE — Use standard evacuating techniques. Af­
ter evacuating system, weigh in the specified amount of re­
frigerant. (Refer to Table 1.)
LOW CHARGE COOLING - Use Cooling Charging Chart,
Fig. 6. Vary refrigerant until the conditions of the chart are
met. Note the charging chart is different from type nor­
mally used. Chart is based on charging the units to the cor­
rect subcooling for the various operating conditions. Accu­
rate pressure gage and temperature sensing device are required.
Connect the pressure gage to the service port on the liquid
line service valve. Mount the temperature sensing device
on the liquid line, close to the liquid line service valve and
insulate it so that outdoor ambient temperature does not af­
fect the reading. Indoor-air cfm must be within the normal
operating range of the unit.
Operate unit and adjust charge to conform with charging
chart, using liquid pressure and temperature to read chart.
TO USE COOLING CHARGING CHART - Initially charge
with 7 lbs. R-22. Place pressure gage at liquid line service
valve. Install thermocouple to liquid line near the liquid line
service valve. Operate unit. Plot liquid pressure and tem­
perature on chart and add or reduce charge to meet curve.
Fig. 5 - Field Control Wiring Raceway
CHARGING
CHART
- 38
AK
007 OUTDOOR FAN MUST BE OPERATIN
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.
/
g
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Q
1 AC
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UJ
1 i
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7
2
5
o 2
2
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/ « XX£ : h UMe
IF
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ave
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s h 0 r
UOUiO
0 2
PRESSURE
0 25
LIQUID
0 31
VALVE (PS
0 3!
IG
)
i
0 400
Fig. 6 — Cooling Charging Chart — 38AK007