Daikin Roofpak Heating and Cooling IM 738-2: Maintenance

Installation and maintenance must be performed only by qualified personnel who are experienced with this type of equipment and familiar with local codes and regulations.

Servicing Control Panel Components

Disconnect all electric power to the unit when servicing control panel components. Before servicing, always inspect units for multiple disconnects to ensure all power is removed from the control panel and its components.

Planned Maintenance

Preventive maintenance is the best way to avoid unnecessary expense and inconvenience. Have this system inspected at regular intervals by a qualified service technician. The required frequency of inspections depends upon the total operating time and the indoor and outdoor environmental conditions.

Unit Storage

Location

The Daikin Rooftop Packaged System Unit is an outdoor unit. However, the schedule may dictate storage either on the ground or in its final position at the site.

If the unit is stored on the ground, additional precautions should be taken as follows:

Make sure that the unit is well supported along the length of the base rail.
Make sure that the unit is level (no twists or uneven ground surface).
Provide proper drainage around the unit to prevent flooding of the equipment
Provide adequate protection from vandalism, mechanical contact, etc. The condenser fins are particularly vulnerable to damage by even light contact with ground based objects.
Make sure all doors are securely closed.
If isolation dampers are provided, verify that they are properly installed and fully closed to prevent the entry of animals and debris through the supply and return air openings
Units without isolation dampers should be fitted with covers over the supply and return air openings.

Winterizing Water Coils

Coil freeze-up can be caused by such things as air stratification and failure of outdoor dampers and/or preheat coils. Routine draining of water cooling coils for winter shutdown cannot be depended upon as insurance against freeze-up. Severe coil damage may result.

It is recommended that all coils be drained as thoroughly as possible and then treated in the following manner.

Fill each coil independently with an antifreeze solution using a small circulating pump and again thoroughly drain.
Check freezing point of antifreeze before proceeding to next coil. Due to a small amount of water always remaining in each coil, there will be a diluting effect. The small amount of antifreeze solution remaining in the coil must always be concentrated enough to prevent freeze-up.
Note: Carefully read instructions for mixing antifreeze solution used. Some products have a higher freezing point in their natural state than when mixed with water.

Installation and maintenance must be performed only by qualified personnel who are experienced with this type of equipment and familiar with local codes and regulations.

Servicing Control Panel Components

Disconnect all electric power to the unit when servicing control panel components. Before servicing, always inspect units for multiple disconnects to ensure all power is removed from the control panel and its components.

Planned Maintenance

Preventive maintenance is the best way to avoid unnecessary expense and inconvenience. Have this system inspected at regular intervals by a qualified service technician. The required frequency of inspections depends upon the total operating time and the indoor and outdoor environmental conditions.

Routine maintenance should cover the following items:

Tighten all belts, wire connections, and setscrews.

Clean the 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.

Lubricate the motor and fan shaft bearings.

Align or replace the belts as needed.

Clean or replace the filters as needed.

Check each circuit's refrigerant sightglass when the circuit is operating under steady-state, full load conditions. The sightglass should then be full and clear. If it is not, check for refrigerant leaks.

Note: A partially full sight glass is not uncommon at part load conditions.

Check for proper superheat.

Check for blockage of the condensate drain. Clean the condensate pan as needed.

Check the power and control voltages.

Check the running amperage of all motors.

Check all operating temperatures and pressures.

Check and adjust all temperature and pressure controls as needed.

Check and adjust all damper linkages as needed.

Check the operation of all safety controls.

Examine the gas furnace (see Bulletin No. IM 684 or IM 685).

Check the condenser fans and tighten their setscrews.

Lubricate the door latch mechanisms.

Unit Storage

Location

The Daikin Rooftop Packaged System Unit is an outdoor unit. However, the schedule may dictate storage either on the ground or in its final position at the site.

If the unit is stored on the ground, additional precautions should be taken as follows:

Make sure that the unit is well supported along the length of the base rail.

Make sure that the unit is level (no twists or uneven ground surface).

Provide proper drainage around the unit to prevent flooding of the equipment

Provide adequate protection from vandalism, mechanical contact, etc. The condenser fins are particularly vulnerable to damage by even light contact with ground based objects.

Make sure all doors are securely closed.

If isolation dampers are provided, verify that they are properly installed and fully closed to prevent the entry of animals and debris through the supply and return air openings

Units without isolation dampers should be fitted with covers over the supply and return air openings.

Winterizing Water Coils

Coil freeze-up can be caused by such things as air stratification and failure of outdoor dampers and/or preheat coils. Routine draining of water cooling coils for winter shutdown cannot be depended upon as insurance against freeze-up. Severe coil damage may result.

It is recommended that all coils be drained as thoroughly as possible and then treated in the following manner.

Fill each coil independently with an antifreeze solution using a small circulating pump and again thoroughly drain.

Check freezing point of antifreeze before proceeding to next coil. Due to a small amount of water always remaining in each coil, there will be a diluting effect. The small amount of antifreeze solution remaining in the coil must always be concentrated enough to prevent freeze-up.

Note: Carefully read instructions for mixing antifreeze solution used. Some products have a higher freezing point in their natural state than when mixed with water.