GVZC20 Service Manual

SYSTEM OPERATION
10
• Prole D (default) ramps up to 50% of the demand
for 1/2 minute, then ramps to 82% of the full cooling
demand airow and operates there for approximately
7 1/2 minutes. The motor then steps up to the full
demand airow. Prole D has a 1/2 minute at 50%
airow OFF delay.
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This menu allows for the adjustment of several heating
performance variables. Heat Airow trim (*1), Heat Fan ON
Delay, Heat Fan OFF Delay and timed Defrost interval can
be adjusted in this menu. Time interval of 30, 60, 90 and
120 minutes between two defrost cycles can be set to suit
the weather conditions and performance of the unit.


User can change the airow trim at high, intermediate and
low for cooling and heat pump heating mode.
Select:
Cool/Heat Airow Trim (High): high speed cooling/heating
Cool/Heat Airow Trim (Int): intermediate speed cooling/
heating Cool/Heat Airow Trim (Low): low speed cooling/
heating Under each trim setting, the airow can be in-
creased or decreased by a certain percentage.
*1
1) At Cool and Heat Hi speed trim, *VZC200601* with
**VC960804C, **VM970804C and *MVC800804C com-
bination trim more than 5% settings are invalid. Trimmed
up CFM makes miss matching error.
2) At Cool Hi speed trim, Other than the above, depending
on the connected indoor unit, there are restrictions on
the positive side Trim setting.
If you want to change the Cool Airow Trim to positive
side, be sure to conrm the Airow Trim restrictions in
the latest indoor unit installation manual. The latest
manual can be obtained from the website “Partner-
Link(InfoFinderPlus/ Literature)”.
[PartnerLink URL]
https://partnerlinkmarketing.goodmanmfg.com/goodman/
info-nder-plus
3) At Cool Intermediate and Low speed trim, The Inverter
system uses lower compressor speed and lower indoor
unit CFM to optimize system performance. To obtain
100% CFM for home circulation, use full Trim setting
instead of Int/Low speed. This is recommended for ap-
plications with unusually cold return temperatures such
as basements.

When Dehumidication mode exists, the circulating fan out-
put is reduced, increasing system run time, over cooling the
evaporator coil and ultimately removing more humidity from
the structure than if only in cooling mode.
The system can have Dehumidication operation in setting
“Standard”, “A”, “B” or “C” of “dehumidify with cooling” menu
based on dehumidication demand.
Setting “Standard” allows for the widest compressor opera-
tion range with lower CFM than Cooling mode.
In the Enhanced Dehumidication (setting A, B and C)
the indoor airow is lower than Standard Dehumidication
(Standard).
Setting “A” allows for the same compressor operation range
in Dehumidication operation with lower CFM than standard
dehumidication (Standard).
Setting “B” limits compressor operation range and keeps
high dehumidication capacity.
In setting “C” the system runs xed at 100% compressor
and airow. See Figure 1.
NOTE: In high humidity environments, sweating on supply
ducts, cased coils or air handler cabinets can become an
issue in Enhanced Dehumidication operation. It is strongly
recommended covering then with 2” berglass insulation for
these installations.
* The specication of *VZC200241AF, 0361AE, 0481AE
and 0601AE or earlier models are di󰀨erent from this
specication.
For details, see the Installation Manual or Service Manual
that matches the Major and Minor revision of model name.