108
Table 37 — C.TYP=9 (VAV Setpoint) Required Configuration
Table 38 — Space Temperature Control Mode
Response for C.TYP=9
38APD Units
— On a call for cooling, the Indoor Fan Status
Cir A (
Inputs
o
GEN.I
o
ID.F.A
) is checked. The switch must
be closed before the capacity routine will start. The lead circuit
is determined. See Lead/Lag Determination on page 112. The
lead compressor will be determined and started. See Circuit
Compressor Staging on page 112. If the lead compressor is a
digital compressor and is enabled, the compressor will start
fully loaded for 90 seconds prior to starting to cycle between
loaded and unloaded. Compressors will be staged until the
unit’s supply air temperature meets the Control Point (
CTPT
)
as described in Supply Air Temperature Control on page 110.
If additional capacity requires the lag circuit to start, the lag
circuit’s lead compressor will be determined and started. Dur-
ing operation, the controls will stage the condenser fans to
maintain head pressure. See Head Pressure Control on
page 117.
As part of normal operation, if a single compressor in a mul-
tiple compressor circuit (38APD040-130) operates for the cu-
mulative time of 60 minutes without an increase in circuit ca-
pacity, an oil recovery routine is initiated. When this routine is
initiated, a second compressor in the circuit is started. Once
started, the normal capacity control routine takes priority and
will turn off the compressor if needed.
As the capacity requirement begins to decrease, the ma-
chine controls will reduce the unit’s capacity to maintain the
Control Point. If the unit is equipped with Minimum Load
Control, it will not be active until the unit is on its last stage of
capacity.
38APS Units
— On a call for cooling, the Indoor Fan Status
Cir A (
Inputs
o
GEN.I
o
ID.F.A
) is checked. The switch must
be closed before the capacity routine will start. The lead com-
pressor will be determined and started. See Circuit Compres-
sor Staging on page 112. If the lead compressor is a digital
compressor and is enabled, the compressor will start fully
loaded for 90 seconds prior to starting to cycle between loaded
and unloaded. Compressors will be staged until the unit’s sup-
ply air temperature meets the Control Point (
CTPT
) as
described in Supply Air Temperature Control on page 110.
During operation, the controls will stage the condenser fans to
maintain head pressure. See Head Pressure Control on
page 117.
As part of normal operation, if a single compressor operates
for the cumulative time of 60 minutes without an increase in
circuit capacity, an oil recovery routine is initiated. When this
routine is initiated, a second compressor in the circuit is started.
Once started, the normal capacity control routine takes priority
and will turn off the compressor if needed.
As the capacity requirement begins to decrease, the ma-
chine controls will reduce the unit’s capacity to maintain the
Control Point. If the unit is equipped with Minimum Load
Control, it will not be active until the unit is on its last stage of
capacity.
CONFIGURATION MODE
SUBMODE
ITEM
DISPLAY
ITEM DESCRIPTION
COMMENT
OPT1
RAT.T
X
RAT Thermistor Type
Default: 0
Range: 0 to 2
Must be set for appropriate value:
0 = 5 k
:
1 = 10 k
:
2 = None
SAT.T
X
SAT Thermistor Type
Default: 0
Range: 0 to 2
Must be set for appropriate value:
0 = 5 k
:
1 = 10 k
:
2 = None
EMM
YES/NO
EMM Module Installed
Default: YES, if factory installed; NO, if
not.
EMM must be installed and configured
for YES.
OPT2
C.TYP
X
Machine Control Type
Default: 4
Range: 1 to 9
Set Item to 9 (VAV Setpoint)
SETPOINTS MODE
COOL
CSP.1
XX.X
Cooling Setpoint 1
Default: 60.0 F (15.6 C)
Range: 40.0 to 80.0 F (4.4 to 26.7 C)
CONTROL MODE
STAT
INDOOR FAN
STATUS CIR A
ID.F.A
SPACE
TEMPERATURE
CONTROL MODE
SPT.M
1
(Off Local)
Off
or
On
0
(Cool Off)
2
(Off CCN)
Off
or
On
0
(Cool Off)
3
(Off Time)
Off
or
On
0
(Cool Off)
4
(Off Emrgcy)
Off
or
On
0
(Cool Off)
5
(On Local)
On
3
(Cool On)
6
(On CCN)
On
3
(Cool On)
7
(On Time)
On
3
(Cool On)
8
(IDFS Not On)
Off
3
(Cool On)
9
(SPT Satisfied)
Not Applicable