Carrier 38EV024320 - Manual (Page 40)

STEP 6—Service And Maintenance
TABLE OF CONTENTS
38EV, 38QV Outdoor Unit Service and Maintenance Page
—Replacement of:
Service Valves......................................................................40
Refrigeration Cod............................................................... 40
Control Box..........................................................................40
Outdoor Pan........................................................................ 41
Compressor......................................................................... 41
Reversing Valve.................................................................. 41
Main Control Board........................................................... 41
Thermistors............ ...........................................................41
Contactor............................................................................. 42
Emergency Stop Switch (ESS)...........................................42
Solenoid Expansion Valve (SEV)...................................... 42
Outdoor Unit................................................................... 42
Indoor Unit...................................................................... 42
Interface Cable....................................................................42
Low, High Pressure Switches............................................ 43
Crankcase Heater, Switch and Fan Motor...................... 43
Electrical Terminals, Connectors......................................43
—Elimination of Television, Radio Interference
—Maintenance:
Fan Motor Lubrication 43
Compressor Oil. .. . . . . . . . . . . . ............. ...........................................................................43
Coil and Heat Sink Cleaning............................................. 43
40 QV Fan Cod, 58SSB blower Accessory Service
and Maintenance.....................................................................44
38EV, 38QV Outdoor Unit Service and Maintenance
NOTE: Malfunction of certain electronic control compo­
nents can cause lack of Automatic Emergency Heat initia­
tion. See below for corrective servicing procedures.
Component replacement and maintenance procedures are
covered in this text. Refer to 38EV or 38QV Instadation
Instruction for the foUowing procedures:
—System Startup Checkout
—System Charging
—Optimizer, Electric Heat Lockout Setup
—Blower Speed Checkout, Adjustment
Manual Emergency Heat Activation—
38EV and 38QV systems are designed to automaticaUy pro­
vide emergency gas or electric heat in the event of compres­
sor lockout on a system malfunction.
However, certain system control malfunctions may cause
lack of emergency heat initiation.
In the event that replacement parts are not readdy avadable
in the heating season, malfunction of the main control board
or interface cable can be manuaUy bypassed as described
below to restore gas or electric heat operation.
Note, however, that a malfunction of the interface board
causing inability to control blower speed, or fadure of
blower motor or controUer cannot be bypassed and must be
repaired.
Install a standard thermostat in the heated space for tempo­
rary control untd the system can be repaired. Connect ther­
mostat leads to the indoor unit terminal board across R and
W, as connected in conventional systems. The interface
board wdl control gas or electric heat to setpoint of the tem­
porary thermostat.
COMPONENT REPLACEMENT
Before replacing any component in the entire system, turn
off main power to system. There may be more than one dis­
connect switch. Turn off accessory heater power, if
/tn
applicable.
A WARNING
High voltage circuit remains energized after main dis­
connect is opened. Normal capacitive discharge time is
ten (10) minutes, but this period may be extended indef­
initely by component fadure. Before servicing, always
check with D.C. Voltmeter between contactor terminal
#23 (violet wire) and ground. Do not service until read­
ing is lOVDC or less. Electrical shock can cause per­
sonal injury or death. Always re-install safety shield in
top of control box after servicing.
A CAUTION
Aluminum tubing is used in unit cods. Do not overheat
or place excessive strain on tubing or damage may
result.
NOTE: To remove reversing valve, accumulator or compres­
sor, control box and coil must be removed first. Coil
removes quickly and easdy. The minimal time required for
cod removal facilitates service and component removal. See
instructions below.
SERVICE VALVE REMOVAL-Cod must be removed to
remove screws holding service valves.
COIL REMOVAL
1. Shut off power to indoor and outdoor units.
2. Remove refrigerant from unit, using refrigerant
removal methods described in Carrier Standard Service
Techniques Manual, Chapter 1, Refrigerants. Be sure
system is 0 psig before proceeding.
3. FoUow steps 4 through 12 below.
CONTROL BOX REMOVAL
Make sure power is off to indoor and outdoor units.
4. Remove control box cover (3 screws).
5. Disconnect (3) in-hne electrical connectors in lower con­
trol box.
6. Disconnect power leads and interface cable if control
box cannot be removed and set aside with them
attached.
7. Remove (8) screws securing control box to louvered cas­
ing and (2) securing support legs to base pan.
A WARNING
High voltage circuit remains energized after main dis­
connect is opened. Normal capacitive discharge time is
ten (10) minutes, but this period may be extended indef­
initely by component failure. Before servicing, always
check with D.C. Voltmeter between contactor terminal
#23 (violet wire) and ground. Do not service until read­
ing is lOVDC or less. Always re-instaU safety shield in
top of control box after servicing.
8. Supporting control box with one hand, remove safety
shield and (2) top screws securing box to fan orifice
ring. Remove control box by sliding horizontally away
from unit.
NOTE: Before reinstalling box, gray plastic through-the-
coU vent tube must be removed from control box. Do this by
squeezing top and bottom of vent where it protrudes from
rear of box. Then slide vent out through front of box, taking
care not to damage wires.
Once the box is fuUy reinstalled, slide vent into slot in rear
of box and through existing opening in coil. Make sure front
lip of vent is against rear panel of box.