Checking Transformer And Control Circuit; Checking High Pressure Switch - Daikin DX17VSS B Series Service Instructions Manual

SERVICING
S-4 CHECKING TRANSFORMER AND CONTROL
CIRCUIT
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
A step-down transformer (208/230 or 115 volt primary to
24 volt secondary) is provided with each indoor unit. this
allows ample capacity for use with resistance heaters. the
outdoor sections do not contain a transformer (see indoor
unit WiRinG diAGRAMS on page 66 and 67).
D ALL
ISCONNECT POWER BEFORE SERVICING
1. Remove control panel cover, or etc., to gain access to
transformer.
With power on:
WARNING
L V .
INE OLTAGE NOW PRESENT
2. Using a voltmeter, check voltage across secondary volt-
age side of transformer (R to C).
3. no voltage indicates faulty transformer, bad wiring, or
bad splices.
4. Check transformer primary voltage at incoming line volt-
age connections and/or splices.
5. if line voltage available at primary voltage side of trans-
former and wiring and splices are good, transformer is
inoperative. Replace the transformer.
WARNING
.
WARNING
.
S-12 CHECKING HIGH PRESSURE SWITCH
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
the high pressure switch senses the pressure in the com-
pressor discharge line. if abnormally high condensing pres-
sures develop, the contacts of the switch open, breaking
the control circuit before the compressor motor overloads.
this control is not automatically reset, need to turn main
power off for reset.
Using an ohmmeter, check across PCB side terminals
of high pressure switch wiring with wire on PCB side
removed. if not continuous, the circuit is open. Replace if
necessary.
.
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