Daikin Air-Cooled Split System Condensing Units RCS 025D

The condenser coils are an all-aluminum design including the connections, micro-channels, fins (an oven brazing process brazes the fins to the micro-channel flat tube), and headers.

During the condensing process, refrigerant in the coil passes through the micro-channel flat tubes, resulting in higher efficiency heat transfer from the refrigerant to the airstream.

Connecting the Condenser Coil to Copper Tubing

Because of the low melting point of aluminum (1220°F compared to 1984°F for copper), this brazed joint is performed with a low temperature brazing process.

CAUTION! Potential equipment damage. If a standard copper brazing process is performed at this joint, the process will damage the aluminum connection.

If a leak is found at a copper-aluminum joint, it is recommended that the entire microchannel coil module be replaced. Do not attempt to repair the copper-aluminum joint on site.

Micro-Channel aluminum coil cleaning recommendations

Any detergent left on the coil surfaces will promote corrosion.

When replacing an individual scroll compressor on tandem or trio assemblies, three refrigerant lines must be disconnected and re-assembled:

a. This line (Figure 23) contains the oil sight glass.

b. This line connects to each compressor at “rota-lock” fittings (Figure 24).

c. This line should be disconnected and re-used

a. This is the largest diameter piping.

b. This line is brazed to each compressor.

The steps below are necessary only if the unit has been started.

Each circuit is properly pumped down.

All the refrigerant service valves on each circuit are closed.

Valves are tagged as a warning for the technician who restarts the units.

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.

Danger! Hazardous voltage. Will cause severe injury or death. Disconnect electric power before servicing equipment. More than one disconnect may be required to de-energize the unit.

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.

Clean condenser coils with cold water, if necessary.

Check each circuit’s refrigerant sightglass when the circuit is operating under steady-state, full-load conditions.

Warning: Only authorized personnel should perform this procedure.

Check if the short circuit indicator is functional.

If the motor ampacity changes or the MMP is replaced, adjust the MMP trip points.

Select the motor service factor

For motors with a 1.15 service factor, rotate the arrow on the dial to correspond to the motor FLA.

For motors with a 1.0 service factor, multiply the motor FLA by 0.9; then rotate the arrow on the dial to correspond to that value.

If the MMP has tripped, rotate the knob counterclockwise to the OFF position; then rotate knob clockwise to the ON position.