Checking Transformer And Control Circuit; Checking Contactor And/Or Relays; Checking Contactor Contacts - Daikin DAR09 Service Instructions Manual

SERVICING
NOTE: Consideration must be given to how the heaters are
wired (O.D.T. and etc.). Also safety devices must be checked for
continuity
.
S-4

Checking Transformer And Control Circuit

HIGH VOLTAGE!
Disconnect ALL power before servicing
or installing. Multiple power sources
may be present. Failure to do so may
cause property damage, personal injury
or death.
A step-down transformer (208/240 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 note below).
WARNING
Disconnect ALL power before servicing.
1. Remove control panel cover, or etc., to gain access to trans-
former.
With power ON:
WARNING
Line Voltage now present.
2. Using a voltmeter, check voltage across secondary voltage
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 voltage
connections and/or splices.
5 If line voltage available at primary voltage side of transform-
er and wiring and splices good, transformer is inoperative.
Replace.
S-7

CHECKING CONTACTOR AND/OR RELAYS

HIGH VOLTAGE!
Disconnect ALL power before servicing
or installing. Multiple power sources
may be present. Failure to do so may
cause property damage, personal injury
or death.
The compressor contactor and other relay holding coils are
wired into the low or line voltage circuits. When the control
circuit is
energized, the coil pulls in the normally open contacts or opens
the normally closed contacts. When the coil is de-energized,
springs return the contacts to their normal position.
NOTE: Most single phase contactors break only one side of the
line (L1), leaving 115 volts to ground present at most internal
components.
1. Remove the leads from the holding coil.
2. Using an ohmmeter, test across the coil terminals.
If the coil does not test continuous, replace the relay or contac-
tor.
S-8

CHECKING CONTACTOR CONTACTS

WARNING
Disconnect ALL power before servicing.
SINGLE PHASE:
1. Disconnect the wire leads from the terminal (T) side of the
contactor.
2. With power ON, energize the contactor.
WARNING
Line Voltage now present.
3. Using a voltmeter, test across terminals.
A. L2 - T1 - No voltage indicates CC1 contacts open.
If a no voltage reading is obtained - replace the contactor.
VOLT/OHM
METER
Ohmmeter for testing holding coil
Voltmeter for testing contacts
TESTING COMPRESSOR CONTACTOR
THREE PHASE
Using a voltmeter, test across terminals:
A. L1-L2, L1-L3, and L2-L3 - If voltage is present, proceed to B. If
voltage is not present, check breaker or fuses on main power
supply..
B. T1-T2, T1-T3, and T2-T3 - If voltage readings are not the
same as in "A", replace contactor.
53
T2
CC
L2
(Single Phase)
T1
L1