Checking Contactor And/Or Relays; Checking Contactor Contacts; Checking Fan Relay Contacts - Daikin DP14UM Service Instructions Manual

SERVICING
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.
Disconnect ALL power before servicing.
1. Remove control panel cover, or etc., to gain access to
transformer.
With power ON:
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
transformer 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.
12
WARNING
WARNING
WARNING
If the coil does not test continuous, replace the relay or
contactor.
S-8 Checking Contactor Contacts
Single Phase
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.
1. Disconnect the wire leads from the terminal (T) side
of the contactor.
2. With power ON, energize the contactor.
Line voltage now present
Testing Compressor Contactor
(Single Phase)
3. Using a voltmeter, test across terminals.
A. L1 - L2 - No voltage. Check breaker or fuses on
main power supply.
B. L2 - T1 - No voltage indicates CC1 contacts
open.
If a no voltage reading is obtained - replace the contactor.
WARNING
WARNING