Checking Voltage; Checking Wiring; S-3A Thermostat And Wiring; S-3E Daikin Communicating Thermostat - Daikin DX17VSS B Series Service Instructions Manual

SERVICING
S-1 CHECKING VOLTAGE
1. Remove outer case, control panel cover, etc., from unit
being tested.
With power on:
WARNING
L V .
INE OLTAGE NOW PRESENT
2. Using a voltmeter, measure the voltage across L1 and
L2 terminals of outdoor unit or at the field connections
for the indoor units or heaters.
3. no reading - indicates open wiring, open fuse(s), no
power 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 (DV*FEC),
Modular Blower, Heater Kit
Gas Furnaces
Cased Coil (CAPE(A)*/CHPE*)
NOTE: When operating electric heaters on voltages oth-
er than 230 volt, refer to the System operation section on
electric heaters to calculate temperature rise and airflow.
Low voltage may cause insufficient heating.
S-2 CHECKING WIRING
WARNING
HIGH VOLTAGE !
D ALL
ISCONNECT POWER BEFORE SERVICING OR
. M
INSTALLING ULTIPLE POWER SOURCES MAY BE
. F
PRESENT AILURE 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.
16
Unit Supply Voltage (VAC)
voltage Min. Max.
208/230 197 253
115 103 126
24 22.6 25.5
.

S-3A THERMOSTAT AND WIRING

WARNING
L V .
INE OLTAGE NOW PRESENT
With power on, check the thermostat.
1. Use a voltmeter to check for 24 volt at thermostat wires
C and R in the thermostat.
2. no voltage indicates trouble in the wiring or transformer
source.
3. Check the continuity of the thermostat and wiring. Re-
pair or replace as necessary.

S-3E DAIKIN COMMUNICATING THERMOSTAT

typical wiring will consist of two wires between the indoor
unit and outdoor unit, and four wires between the indoor
unit and thermostat. the figure that follows shows the
required wires: data lines, 1 and 2; "R" (24 vAC hot) and "C"
(24 vAC common).
<In Case of Air Handler>
1 2 C R
1 2 R C
1 2 R C
<In Case of Cased Coil>
1 2 C R
1 2 R C
1 2 R C
1 2 R C
it is strongly recommended that you do not connect more
than two wires into a single terminal in the field because
there is a risk of the wires becoming loose, which may result
in intermittent operation.
to wire the system components, it is strongly recommend-
ed to use the same type and same gauge for the wires pre-
pared in the field. (for best results, use 18 AWG.) However,
communications reliability may be improved by using a high
quality, shielded, twisted pair cable for the data transmis-
sion lines.
finally, be sure to confirm that the wires do not come off
each terminal after all connections are finished.
Communica�ng Thermostat
(In case of Daikin One+
Smart Thermostat)
125 �. (*)
Air Handler Blower
Integrated Control Module
250 �. (*)
Outdoor unit
Integrated Control Module
Communica�ng Thermostat
(In case of Daikin One+
Smart Thermostat)
125 �. (*)
Cased Coil
Integrated Control Module
Gas Furnace or Module Blower
Integrated Control Module
250 �. (*)
Outdoor unit
Integrated Control Module