Capacity Control-Comfortnet Models; Unloader Solenoid; Coils And Blower Coils - Goodman ComfortNet ASXC160**1AA Series Service Instructions Manual

PRODUCT DESIGN
• Compliant scroll compressors perform "quiet" shutdowns
that allow the compressor to restart immediately without
the need for a time delay. This compressor will restart
even if the system has not equalized.
NOTE: Operating pressures and amp draws may differ
from standard reciprocating compressors. This informa-
tion can be found in the unit's Technical Information
Manual.
CAPACITY CONTROL - COMFORTNET
MODELS
During the compression process, there are several pockets
within the scroll that are compressing gas. Modulation is
achieved by venting a portion of the gas in the first suction
pocket back to the low side of the compressor thereby
reducing the effective displacement of the compressor. See
Figure A. Full capacity is achieved by blocking these vents,
increasing the displacement to 100%. A solenoid in the
compressor, controlled by an external 24-volt ac signal,
moves the slider ring that covers and uncovers these vents.
The vent covers are arranged in such a manner that the
compressor operates somewhere around 67% capacity
when the solenoid is not energized and 100% capacity when
the solenoid is energized. The loading and unloading of the
two step scroll is done "on the fly" without shutting off the
motor between steps. See Figure C below. The unloaded
mode default was chosen for two reasons:
Molded Plug*
Internal Unloader
Coil
24 vdc
*Rectifier is integrated on the UC PCB
FIGURE C
1. It is expected that the majority of run hours will be in the
low capacity, unloaded mode.
2. It allows a simple two-stage thermostat to control capac-
ity through the second stage in both cooling and possibly
heating if desired.

UNLOADER SOLENOID

A nominal 24-volt direct current coil activates the internal
unloader solenoid. The input control circuit voltage must be
28
18 to 28 volt ac. The coil power requirement is 20 VA. The
external electrical connection is made with a molded plug
assembly. This plug is connected to the Communicating
Unitary Control PCB (UC PCB) which contains a full wave
rectifier to supply direct current to the unloader coil.

COILS AND BLOWER COILS

MBVC blower cabinets are designed to be used as a two-
TM
piece blower and coil combination and can be utilized with the
CAUF, CAPF and CAPT coils for upflow and downflow
applications. The CACF and CHPF coils are designed for
horizontal applications. This two-piece arrangement allows
for a variety of mix-matching possibilities providing greater
flexibility.
The MBVC blower cabinets use a variable speed motor that
maintains a constant airflow with a higher duct static. MBVC
blower cabinets are approved for applications with cooling
coils of up to 0.8 inches W.C. external static pressure. The
MBVC models allow airflow trimming of +/-10%.
All units are constructed with R-4.2 insulation. In areas of
extreme humidity (greater than 80% consistently), insulate
the exterior of the blower with insulation having a vapor barrier
equivalent to ductwork insulation, providing local codes
permit.
AVPTC Multi-Position Air Handler
AVPTC is a multi-position, variable-speed air handler used
with R-410A and are available in 2 to 5 ton sizes with optional
3 kW to 25kW electric heat kits available for field installation.
The AVPTC unit's blower design includes a variable-speed
Line
ECM motor and is compatible with heat pumps and variable-
Run Capacitor
capacity cooling applications.
This appliance can be installed in the vertical or left horizontal
position without modification. The horizontal right and downflow
Line
positions require product modification. This product is de-
signed for zero inches (0 inches) clearance; however, ad-
equate access for service or replacement must be consid-
ered without removing permanent structure. This unit can be
installed on a platform when deemed necessary.
In an attic installation a secondary drain pan must be provided
by the installer and placed under the entire unit with a
separate drain line properly sloped and terminated in an area
visible to the owner. This secondary drain pan is required in
the event that there is a leak or main drain blockage. Closed
cell insulation should be applied to the drain lines in uncon-
ditioned spaces where sweating may occur.