Carrier 38APD130 - Space Temperature Control Mode Response for C.TYP=8

107
Table 36 — Space Temperature Control Mode Response for C.TYP=8
C.TYP = 9 (VAV SETPOINT) — With this configuration, the
38AP unit operates as a VAV unit and controls unit capacity in
an attempt to meet a field-supplied 4 to 20 mA supply air tem-
perature request, by staging compressors to attempt to meet the
current Control Point (Run Status
o
VIEW
o
CTPT). A field-
supplied 4 to 20 mA signal determines the Active Setpoint,
(Run Status
o
VIEW
o
SETP). The Control Point is the Ac-
tive Setpoint Run Status
o
VIEW
o
SETP adjusted for any
temperature reset that is applied. See Temperature Reset on
page 129 for information on Temperature Reset. This control
type requires the energy management module option or
accessory.
This configuration is compatible with both standard and
digital compressors.
Recommended Applications
— This control type is used
when variable supply air set points are required and determined
by a third-party Building Management System.
Hardware Requirements
• energy management module
• 4 to 20 mA generator
• return/mixed air sensor
• supply air sensor
This control scheme requires a supply air sensor and a re-
turn air sensor or mixed air sensor. In lieu of wiring sensors to
the 38AP unit, both values can be communicated via CCN to
the 38AP unit. For information on broadcasting values, see
Thermistors on page 28. The Supply Configuration
o
OPT1
o
SAT.T (SAT Thermistor Type) and Configuration
o
OPT1
o
RAT.T (RAT Thermistor Type) must be configured for
either 0 (5 k:) or 1 (10 k:) type sensors whether they are hard
wired or their values are communicated to the controller.
Required Configurations
— Table 37 lists the configurations
required for proper operation.
Recommended Settings
— With this Control Type, CSP.1
should be set to the design supply air temperature used most
often.
Wiring
— See Fig. 141.
Sequence of Operation
— The 4-20 mA Cooling Set Point
(Inputs
o
4-20
o
CL.MA) is translated into a desired active set
point ranging from 40 to 80 F (4.4 to 26.7 C). The control
translates the input linearly with 4 mA equal to 40 F (4.4 C)
and 20 mA equal to 80 F (26.7 C) as the basis for the Active
Set Point (Run Status
o
VIEW
o
SETP). With the loss of the
field-supplied signal, the Active Setpoint will change to Cool-
ing Set Point 1 (Set Points
o
COOL
o
CSP.1). See Fig. 142
and 143.
The Control Point (Run Status
o
VIEW
o
CTPT) is the Ac-
tive Set Point (SETP) or Cooling Set Point 1 (CSP.1) adjusted
for any temperature reset that is applied. See Temperature Re-
set on page 129 for additional information.
For mechanical cooling, the unit’s Control Method (Config-
uration
o
OPT2
o
CTRL) and inputs must allow the machine
to run. See Control Methods on page 60 for additional informa-
tion.
On power up or changing from Off to Enabled, the machine
will remain off until Minutes Off Time (Configuration
o
OPT2
o
DELY) timer has expired. See Minutes Off Time on
page 128 for additional information. Liquid line solenoid valve
operation is as described in Liquid Line Solenoid Valves on
page 40. Time Guard is honored for all compressors. For spe-
cific information on Time Guard, see MDTG - Time Guard
Active on page 135.
In this Control Type, Space Temp Control Mode, Run
Status
o
VIEW
o
SPT.M=0 (Off Cool) as long as Run
Status
o
VIEW
o
STAT=1 (Off Local), 2 (Off CCN), 3 (Off
Time) or 4 (Off Emrgcy). SPT.M=3 (Cool On) when Control
Mode, STAT=5 (On Local), 6 (On CCN), or 7 (On Time). In
this Control Type, if the Indoor Fan Status Switch opens (In-
puts
o
GEN.I
o
ID.F.A=OFF) Control Mode (STAT) will
change to 8 (IDFS Not On); the unit will alarm and switch to 4
(Off Emrgcy). Table 38 shows the space temperature control
mode response for C.TYP=9.
CONTROL MODE STAT
Y1 STATUS
Y.1
AND/OR
Y3 STATUS
Y.3
Y2 STATUS
Y.2
AND/OR
Y4 STATUS
Y.4
INDOOR FAN STATUS CIR A
ID.F.A
AND/OR
INDOOR FAN STATUS CIR B
ID.F.B
SPACE TEMPERATURE
CONTROL MODE
SPT.M
1 (Off Local) Off or On Off or On Off or On 0 (Off Cool)
2 (Off CCN) Off or On Off or On Off or On 0 (Off Cool)
3 (Off Time) Off or On Off or On Off or On 0 (Off Cool)
4 (Off Emrgcy) Off or On Off or On Off or On 0 (Off Cool)
5 (On Local)
Off Off Off or On 0 (Off Cool)
On Off On 1 (Lo Cool)
Off or On On On 2 (Hi Cool)
6 (On CCN)
Off Off Off or On 0 (Off Cool)
On Off On 1 (Lo Cool)
Off or On On On 2 (Hi Cool)
7 (On Time)
Off Off Off or On 0 (Off Cool)
On Off On 1 (Lo Cool)
Off or On On On 2 (Hi Cool)
8 (IDFS Not On) Off or On Off
or On Off 0 (Off Cool)
9 (SPT Satisfied) Not Applicable