51
Configuration
→
AIR.Q
→
IA.FN
= 2
(Always) — The indoor
fan performance for
IA.FN
= 2
is the same as the performance
when
IA.FN
= 1
except the algorithm is not limited to occu-
pied periods only. The fan can be triggered on when the space
is occupied or unoccupied.
FAN ENABLE (IAQ Switch Input) — The DCV algorithm
will operate whenever the building is occupied and the indoor
fan is operating or the whenever the IAQ algorithm has caused
the indoor fan to operate. The configuration
Configuration
→
AIR.Q
→
II.FN
(IAQ Switch Input Fan CFG) determines
whether or not the IAQ algorithm can turn on the indoor fan.
If the indoor fan is not operating, the economizer position
will be zero. The damper position may exceed
Configuration
→
AIR.Q
→
EC.MN
to provide economizer cooling.
Configuration
→
AIR.Q
→
II.FN
= 0
(Never) — When
II.FN
= 0
, the IAQ algorithm can never turn on the fan.
Configuration
→
AIR.Q
→
II.FN
= 1
(Occupied) — When
II.FN
= 1
, the IAQ algorithm will turn on the indoor fan when-
ever the building is occupied and IAQ is high. The indoor fan
will turn off if IAQ returns to normal.
Configuration
→
AIR.Q
→
II.FN
= 2
(Always) — The indoor
fan performance for
II.FN
= 2
is the same as the performance
when
II.FN
= 1
except the algorithm is not limited to occupied
periods only. The fan can be triggered on when the space is
occupied or unoccupied.
Temperature Compensated Start —
This logic is
used when the unit is in the unoccupied state. The control will
calculate early Start Bias time based on Space Temperature
deviation from the occupied cooling and heating set points.
This will allow the control to start the unit so that the space is at
conditioned levels when the occupied period starts. This is
required for ASHRAE 90.1 compliance. This control function
requires a valid occupancy schedule. A space sensor is required
for non-linkage applications.
SETTING UP THE SYSTEM — The settings for tempera-
ture compensated start can be found in the local display under
Configuration
→
UNIT
.
Temp Comp Strt Cool Factr (
TCS.C
) — This is the factor for
the start time bias equation for cooling.
Temp Lamp Strt Heat Factr (
TCS.H
) — This is the factor for
the start time bias equation for heating.
NOTE: Temperature compensated start is disabled when these
factors are set to 0.
TEMPERATURE COMPENSATED START LOGIC — The
following conditions must be met for the algorithm to run:
• Unit is in unoccupied state.
• Next occupied time is valid.
• Current time of day is valid.
• Valid space temperature reading is available (sensor or
CCN network).
The algorithm will calculate a Start Bias time in minutes us-
ing the following equations:
If (space temperature > occupied cooling set point)
Start Bias Time = (space temperature – occupied cooling set
point)*
TCS.C
If (space temperature < occupied heating set point)
Start Bias Time = (occupied heating set point – space
temperature)*
TCS.H
When the Start Bias Time is greater than zero the algorithm
will subtract it from the next occupied time to calculate the new
start time. When the new start time is reached, the Temperature
Compensated Start mode is set, the fan is started and the unit
controlled as in an occupied state. Once set, Temperature
Compensated mode will stay on until the unit goes into the
Occupied mode. The Start Bias Time will be written into the
CCN Linkage Equipment Table if the unit is controlled in DAV
mode. If the Unoccupied Economizer Free Cool mode is active
when temperature compensated start begins, the Unoccupied
Free Cool mode will be stopped.
Carrier Comfort Network® (CCN) Configura-
tion —
It is possible to configure the
Comfort
Link™ control
to participate as an element of the Carrier Comfort Network
(CCN) system directly from the local display. This section will
deal with explaining the various programmable options which
are found under the CCN sub-menu in the Configuration mode.
The major configurations for CCN programming are
located in the local displays at
Configuration
→
CCN
.
See
Appendix A.
CCN Address (
CCN.A
) — This configuration is the CCN ad-
dress the rooftop is assigned.
CCN Bus Number (
CCN.B
) — This configuration is the
CCN bus the rooftop is assigned.
CCN Baud Rate (
BAUD
) — This configuration is the CCN
baud rate.
CCN Time/Date Broadcast (
BROD
→
B.TIM
) — If this con-
figuration is set to ON, the control will periodically send the
time and date out onto the CCN bus once a minute. If this
device is on a CCN network then it will be important to make
sure that only one device on the bus has this configuration set
to ON. If more than one time broadcaster is present, problems
with the time will occur.
NOTE: Only the time and date broadcaster can perform
daylight savings time adjustments. Even if the rooftop is stand
alone, the user may want to set this to ON to accomplish the
daylight/savings function.
CCN OAT Broadcast (
BROD
→
B.OAT
) — If this configura-
tion is set to ON, the control will periodically broadcast its
outside-air temperature at a rate of once every 30 minutes.
Global Schedule Broadcast (
BROD
→
B.GS
) — If this con-
figuration is set to ON and the schedule number (
SCH.N
) is be-
tween 65 and 99, then the control will broadcast the internal
time schedule once every 2 minutes.
CCN Broadcast Acknowledger (
BROD
→
B.ACK
) — If this
configuration is set to ON, then when any broadcasting is done
on the bus, this device will respond to and acknowledge. Only
one device per bus can be configured for this option.
Schedule Number (
SCH.O
→
SCH.N
) — This configuration
determines what schedule the control may follow.
SCH.N
= 0
The control is always occupied.
SCH.N
= 1
The control follows its internal time sched-
ules. The user may enter any number
between 1 and 64 but it will be overwritten
to “1” by the control as it only has one
internal schedule.
SCH.N
= 65-99
The control is either set up to receive to a
broadcasted time schedule set to this number
or the control is set up to broadcast its inter-
nal time schedule (
B.GS
) to the network and
this is the global schedule number it is
broadcasting. If this is the case, then the con-
trol still follows its internal time schedules.
Accept Global Holidays? (
SCH.O
→
HOL.G
) — If a device
is broadcasting the time on the bus, it is possible to accept the
time yet not accept the global holiday from the broadcast
message.
Override Time Limit (
SCH.O
→
OV.TL
) — This configura-
tion allows the user to decide how long an override occurs
when it is initiated. The override may be configured from 1 to
4 hours. If the time is set to 0, the override function will
become disabled.
ITEM
EXPANSION
RANGE UNITS CCN POINT
TCS.C
Temp.Cmp.Strt.Cool Factr 0 - 60
min
TCSTCOOL
TCS.H
Temp.Cmp.Strt.Heat Factr 0 - 60
min
TCSTHEAT
Summary of Contents for 48PG24
Page 68: ...68 Fig 14 Low Voltage Control Schematic 48PG20 28 Units without Humidi MiZer System a48 7627...
Page 69: ...69 Fig 15 Low Voltage Control Schematic 48PG20 28 Units with Humidi MiZer System a48 8227...
Page 70: ...70 Fig 16 Low Voltage Control Schematic 50PG20 28 Units without Humidi MiZer System a48 7778...
Page 71: ...71 Fig 17 Low Voltage Control Schematic 50PG20 28 Units with Humidi MiZer System a50 8101...
Page 72: ...72 Fig 18 Power Schematic Units without Humidi MiZer System a48 7628...
Page 73: ...73 Fig 19 Power Schematic Units with Humidi MiZer System a48 8228...
Page 74: ...74 Fig 20 Component Arrangement Units without Humidi MiZer System a48 8229...
Page 75: ...75 Fig 21 Component Arrangement Units with Humidi MiZer System a48 8230...
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