Servicing; Checking Voltage; Checking Wiring; Checking Thermostat, Wiring - Maytag Amana SXV9 Series Service And Troubleshooting

SERVICING

CHECKING VOLTAGE

1. Remove outer case, control panel cover, etc., from unit
being tested.
With power ON:
Line voltage now present.
2. Using a voltmeter, measure the voltage across terminals
L1 and L2 of the contactor for the Air Conditioner con-
denser unit or at the field connections for the air handler
or heaters.
ComfortNet™ Ready Air Conditioner Condenser
Units: Measure the voltage across the L1 and L2 lugs
on the unitary (UC) control.
3. No reading - indicates open wiring, open fuse(s) no pow-
er or etc., from unit to fused disconnect service. Repair
as needed.
4. With ample voltage at line voltage connectors, energize
the unit.
Unit Type
Outdoor Unit, Air Handler,
Modular Blower, Heater Kit
Gas Furnaces
NOTE: When operating electric heaters on voltages other
than 240 volt, refer to the System Operation section on
electric heaters to calculate temperature rise and air flow.
Low voltage may cause insufficient heating.

CHECKING WIRING

HIGH VOLTAGE
Disconnect all power before servicing or
installing this unit. Multiple power sources
may be present. Failure to do so may cause
property damage, personal injury or death.
1. Check wiring visually for signs of overheating, damaged
insulation and loose connections.
2. Use an ohmmeter to check continuity of any suspected
open wires.
3. If any wires must be replaced, replace with comparable
gauge and insulation thickness.
CHECKING THERMOSTAT AND WIRING
Communicating Thermostat Wiring: The maximum wire
length for 18 AWG thermostat wire is 250 feet.
WARNING
Unit Supply Voltage (VAC)
voltage min.
208/230 197
115 103
WARNING

THERMOSTAT AND WIRING

Line voltage now present.
With power ON, thermostat calling for cooling/heating.
1. Use a voltmeter to check for 24 volt at thermostat wires
C and R in the indoor unit control panel.
2. No voltage indicates trouble in the thermostat, wiring or
transformer source.
3. Check the continuity of the thermostat and wiring. Repair
or replace as necessary.
Line voltage now present.
RESISTANCE HEATERS
With power ON:
1. Set room thermostat to a higher setting than room
temperature so both stages call for heat.
2. With voltmeter, check for 24 volt at each heater relay.
3. No voltage indicates the trouble is in the thermostat or
wiring.
max.
4. Check the continuity of the thermostat and wiring.
253
Repair or replace as necessary.
126
NOTE: Consideration must be given to how the heaters
are wired (O.D.T. and etc.). Also safety devices must be
checked for continuity.
THERMOSTAT COMFORTBRIDGE™ SYSTEM
OVERVIEW
The ComfortBridge based inverter heating and air condi-
tioning system uses an indoor unit and outdoor unit digitally
communicating with one another via a two-way communica-
tions path.
The 24 VAC single-stage thermostat sends commands to
the indoor and outdoor units.
The indoor and outdoor units interacting with one another
directly while taking simple analog commands from the ther-
mostat are the core of unlocking the benefits and features
of the ComfortBridge control system.
NOTE: It is strongly recommend the use of thermostat
with humidity sensor and dehumidification terminal. Without
these functions, Dehumidification operation does not work.
WARNING
WARNING
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