Product Design; Condensing Unit - Daikin ComfortNet DX16TC Series Service Instructions Manual

PRODUCT DESIGN

This section gives a basic description of cooling unit operation,
its various components and their basic operation. Ensure
your system is properly sized for heat gain and loss according
to methods of the Air Conditioning Contractors Association
(ACCA) or equivalent.

CONDENSING UNIT

The condenser air is pulled through the condenser coil by a
direct drive propeller fan. This condenser air is then discharged
out of the top of the cabinet. These units are designed for free
air discharge, so no additional resistance, like duct work, shall
be attached.
The suction and liquid line connections on present models are
of the sweat type for field piping with refrigerant type copper.
Front seating valves are factory installed to accept the field run
copper. The total refrigerant charge for a normal installation is
factory installed in the condensing unit.
DX16TC, DZ16TC, DX18TC, DZ18TC models are available in
2 through 5 ton sizes and use R-410A refrigerant. They are
designed for 208/230 volt single phase applications.
DX16TC, DZ16TC, DX18TC, DZ18TC R-410A model units use
the Copeland Scroll "Ultratech" Series compressors which are
specifically designed for R-410A refrigerant. These units also
have Copeland® ComfortAlert diagnostics. The Copeland®
ComfortAlert diagnostics are integrated into the unitary (UC)
control. These models are ComfortNetTM ready.
There are a number of design characteristics which are differ-
ent from the traditional reciprocating and/or scroll compres-
sors.
"Ultractech" Series scroll compressors will not have a discharge
thermostat. Some of the early model scroll compressors re-
quired discharge thermostat.
"Ultratech" Series scroll compressors use "POE" or polyolester
oil which is NOT compatible with mineral oil based lubricants
like 3GS. "POE" oil must be used if additional oil is required.
The DX16TC, DZ16TC, DX18TC, DZ18TC series split system units
use a two-stage scroll compressor. The two-step modulator
has an internal unloading mechanism that opens a bypass port
in the first compression pocket, effectively reducing the dis-
placement of the scroll. The opening and closing of the bypass
port is controlled by an internal electrically operated solenoid.
The ZPS two-step modulated scroll uses a single step of un-
loading to go from full capacity to approximately 67% capacity.
A single speed, high efficiency motor continues to run while
the scroll modulates between the two capacity steps.
A scroll is an involute spiral which, when matched with a mat-
ing scroll form as shown, generates a series of crescent shaped
gas pockets between the two members.
During compression, one scroll remains stationary (fixed scroll)
while the other form (orbiting scroll) is allowed to orbit (but
not rotate) around the first form.
As this motion occurs, the pockets between the two forms are
slowly pushed to the center of the two scrolls while simulta-
neously being reduced in volume. When the pocket reaches
the center of the scroll form, the gas, which is now at a high
pressure, is discharged out of a port located at the center.
During compression, several pockets are being compressed
simultaneously, resulting in a very smooth process. Both the
suction process (outer portion of the scroll members) and the
discharge process (inner portion) are continuous.
Some design characteristics of the Compliant Scroll compres-
sor are:
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FIGURE A