Carrier 38ED - Manual (Page 6)

See Table 4 for recommended wire and fuse sizes.
When making electric connections, provide clear­
ance at unit for refrigerant piping connections.
INSTALL A BRANCH CIRCUIT DISCONNECT
PER NEC of adequate size to handle unit starting
current. Locate disconnect within sight from and
readily accessible from the unit, per section 440-14
of National Electrical Code (NEC).
ROUTE LINE POWER LEADS INTO UNIT —
Extend leads from disconnect thru power wiring
hole provided (see Fig. 1) and into unit splice area.
Remove top cover to gain access to unit wiring.
CONNECT GROUND LEAD AND POWER
WIRING — Connect ground lead to a ground lug in
control box for safety. Then connect power wiring.
See Fig. 6. Splice line power leads to yellow and
black pigtails. Use wire nuts and tape at each con­
nection. Connect unit wiring to copper or copper-
clad aluminum power wiring. Do not connect to
aluminum wiring.
I-PHASE
CONN. TO
DISCONNECT
PER NEC
■------- GROUND LEAD-KDGROUNDING LUG
BLK-----------
-YEL-
I-PHASE
CONO UNIT
Splice Connections
Field Wiring
Factory Wiring
Fig. 6 — Line Power Connections
CONNECT CONTROL POWER WIRING —
Route 24-v control wires thru control wiring hole
and connect to pigtails supplied with unit (Fig. 1).
Splice control leads to black and blue pigtails on all
units. See Fig. 5.
Use a furnace or fan coil transformer as 24-v
(60-va minimum) supply for system as shown in Fig. 5
or use accessory transformer shown in Table 3).
START-UP
1. Backseat (open) liquid and suction line service
valves.
2. Set thermostat selector switch at OFF.
3. Set room thermostat at desired temperature.
Be sure this temperature is below indoor ambient
temperature.
4. Energize electrical disconnects for entire system.
5. Set room thermostat at COOL and fan switch at
FAN or AUTO, as desired. Operate unit for 15
minutes; then cheek system refrigerant charge.
See Refrigerant Charging, this page.
Motors and controls are designed to operate satis-
faetorily in the voltage range shown in Table 4. If
necessary to use manifold gages for servicing, refer
to Carrier Standard Service Techniques Manual,
Chapter 1, Refrigerants, page 1-5, Fig. 8 for bypass
method of returning charge to system. Removal of
liquid line charging hose without following these
precautions could result in some loss of eharge.
Refrigerant Charging
Condensing units contain correct operating
charge for complete system when connected to
Carrier-approved evaporators of same capacity as
condensing unit with 25 ft or less of Carrier acces­
sory tubing or field-supplied tubing of recommended
size. For every 10 ft of liquid line of recommended
size over 25 ft, add refrigerant charge as follows:
.4 lb for 3/8-in. line; .28 lb for 5/ 16-in. line. On all
other systems, adjust charge for correct operation
as applicable.
Service port connections are provided on liquid
and suction line service valves for evacuation and
charging. See Fig. 1.
TO CHECK, ADJUST OR REPLACE REFRIG­
ERANT CHARGE use method recommended in
Table 5. Details of charging methods are listed
below.
Before recharging system, thoroughly evacuate
system and then weigh in refrigerant charge speci­
fied in Table 6. Check or adjust charge as required.
Refer to Carrier Standard Service Techniques
Manual, Chapter 1, Refrigerants, for additional
system evacuation and dehydration instructions.
WEIGHT METHOD — Refer to Table 6 or unit
nameplate for correct system refrigerant charge.
Remove any refrigerant remaining in system before
recharging.
When system is not evaeuated, subtract the
following amount from total charge.
38ED018 thru 036 — .10 lb (1.6 oz)
38ED042 thru 060 — .20 lb (3.2 oz)
The Dial-a-charge charging cylinder is an accu­
rate device used to recharge system by weight. These
cylinders are available at refrigeration supply firms.
CHARGING CHART METHOD — Use Charging
Chart, Fig. 7, and the following procedure.
1. Operate unit a minimum of 10 minutes before
checking charge.