Daikin DBC Series, Installation Instructions Manual

17

During operation the power to the circuit board is 

controlled by a temperature sensor, which is clamped to 

a feeder tube entering the outdoor coil. Defrost timing 

periods of 30,60 and 90 minutes may be selected by 

connecting the circuit board jumper to 30, 60 and 90 

respectively. Accumulation of time for the timing period 

selected starts when the sensor closes (approximately 

31° F), and when the wall thermostat calls for heat. At the 

end of the timing period, the unit’s defrost cycle will be 

initiated provided the sensor remains closed. When the 

sensor opens (approximately 75° F), the defrost cycle is 

terminated and the timing period is reset. If the defrost 

cycle is not terminated due to the sensor temperature, a 

ten minute override interrupts the unit’s defrost period.

MAINTENANCE

WARNING

 ELECTRICAL SHOCK, FIRE OR EXPLOSION HAZARD

Failure to follow safety warnings exactly could 

result in dangerous operation, serious injury, 

death or property damage. 

Improper servicing could result in dangerous 

operation, serious injury, death or property 

damage. 

• 

Before servicing, disconnect all electrical 

power to furnace. 

• 

When servicing controls, label all wires 

prior to disconnecting. Reconnect wires 

correctly. 

• 

Verify proper operation after servicing. 

WARNING

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.

WARNING

To prevent personal injury or death due to 

improper installation, adjustment, alteration, 

service or maintenance, refer to this manual. 

For additional assistance or information, 

consult a qualified installer, servicer agency or 

the gas supplier. 

CAUTION

Sheet metal parts, screws, clips and similar 

items inherently have sharp edges, and it 

is necessary that the installer and service 

personnel exercise caution. 

Preventive maintenance is the best way to avoid 

unnecessary expense and inconvenience. Have this 

system inspected at regular intervals by qualified service 

personnel, at least twice a year. Routine maintenance 

should cover the following items:

1.  Tighten all belts, set screws, and wire connections.

2.  Clean evaporator and condenser coils mechanically 

or with cold water, if necessary. Usually any fouling 

is only matted on the entering air face of the coil and 

can be removed by brushing.

3.  Lubricate motor bearings.

4.  Align or replace belts as needed.

5.  Replace filters as needed (see Filters section).

6.  Check for blockage of condensate drain.

7.  Check power and control voltages.

8.  Check running amperage.

9. 

Check operating temperatures and pressures.

10. Check and adjust temperature and pressure controls.

11.   Check and adjust damper linkages.

12. Check operation of all safety controls.

13. Check condenser fans and tighten set screws.

Filters

CAUTION

To prevent property damage due to fire and loss 

of equipment efficiency or equipment damage due 

to dust and lint build up on internal parts, never 

operate unit without an air filter installed in the 

return air system.

Every application may require a different frequency of 

replacement of dirty filters. Filters must be replaced at least 

every three (3) months during operating seasons.

Dirty filters are the most common cause of inadequate 

heating or cooling performance. Filter inspection should be 

made at least every two months; more often if necessary 

because of local conditions and usage.

Dirty throwaway filters should be discarded and replaced 

with a new, clean filter. 

Disposable return air filters are supplied with this unit. See 

the unit Specification Sheet or Technical Manual for the 

correct size and part number. To remove the filters, remove 

the filter access panel on return side of the unit.