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RH Sensor O n OAQ I nput (RH.S)
This configuration identifies if a space relative humidity sensor is
installed on the outdoor air quality (OAQ) input. A YES value
enables SP.RH display. A NO value disables SP.RH display and
use.
Space Humidity Swi tch (RH.SW)
This configuration identifies if a space relative humidity switch is
installed on the ENTHALPY input, and what status (normally
open, normally closed) the input is when the space humidity is
LOW.
Temperature Compensated Start Cooling Factor
(TCS.C)
This factor is used in the equation of the Temperature
Compensated Start Time Bias for cooling. A setting of 0 minutes
indicates Temperature Compensated Start in Cooling is not
permitted.
Temperature Compensated Start Heati ng Factor
(TCS.H)
This factor is used in the equation of the Temperature
Compensated Start Time Bias for heating. A setting of 0 minutes
indicates Temperature Compensated Start in Heating is not
permitted.
General Operating Sequence
The PD unit must be connected to a space temperature sensor
T--55, T--56, T58 or T59 and will not operate with a conventional
R, Y1, Y2, W1, W2, G, C thermostat. When a T--55, T--56, T58 or
T59 space temperature sensor is connected to the low voltage
terminal board as shown in the Installation Instructions Manual, the
PD unit will try to maintain the Space Temperature
(Temperatures→AIR.T→SPT) at one of four set points: The
Occupied Cool Set Point (Setpoints→OCSP), the Unoccupied
Cool Set Point (Setpoints→UCSP), Occupied Heat Set Point
(Setpoints→OHSP), or the Unoccupied Heat Set Point
(Setpoints→UHSP).
Occupancy Determination
When the building is in occupied mode, the occupied set points are
active. When the building is in unoccupied mode, the unoccupied
set points are active. The PD control will switch automatically
between cooling and heating to maintain temperature. However, to
minimize unnecessary cool to heat and heat to cool changes, there
is a 10 --minute delay after the last stage turns off before the control
will switch modes. The heating and cooling set points are also
separated by a Heat--Cool Set Point Gap (Setpoints→GAP)thatis
user configurable from 2 to 10 degrees F. This parameter prevents
the unit from over cooling the conditioned space to where heating
mode is required or over heating the conditioned space to where
cooling mode is required.
The T55 space temperature sensor senses the temperature in the
conditioned space with no provisions for adjusting the space
temperature set point at the sensor. The T--56 space temperature
sensor senses the temperature in the conditioned space and allows
for adjustment of the space temperature set point by a configurable
number of degrees F higher or a configurable number of degrees F
lower at the space temperature sensor. The T58 space temperature
sensor communicates with the PD unit control board through a
CCN RS--485 +, --, and ground connection. The T59 space
temperature sensor is a T56 s ensor with an integrated temperature
display. A jumper wire is not needed between R and W1 when
using space temperature sensors T55, T56, T58 or T59.
The building’s occupancy is affected by a number of different
factors. When the unit is operating with a space temperature sensor
(T--55, T --56, T--58 or T--59), occupancy affects the unit set points
and the operation of the economizer. The factors affecting
occupancy are listed below from highest to lowest priority.
Level 1 Priority
The CCN point OCCUPIED is forced via an external device such
as a ComfortIDt controller: when OCCUPIED is forced to YES,
the unit is considered occupied, when OCCUPIED is forced to
NO, the unit is considered unoccupied. If OCCUPIED is not being
forced, proceed to the level 2 priority.
Level 2 Priority
Remote Occupancy Switch should be configured to either
Normally Open or Normally Closed when the user would like to
control the occupancy with an external switch. This switch is
field--supplied (24v, single pole, single throw [SPST]). There are
three possible configurations for the remote occupancy switch:
1. (Configuration→UNIT→RM.SW = 0) No Switch
2. (Configuration→UNIT→RM.SW = 1) Normally Open
Switch
3. (Configuration→UNIT→RM.SW = 2) Normally Closed
Switch
If the switch is configured to No Switch (0), the switch input value
will be ignored and software will proceed to level 3 priority. For
each type of switch, the appropriate configuration and states are
listed in the table below.
TYPE OF SWITCH
SWITCH
CONFIGURATION
STATE OF
SWITCH AND
STATE OF
OCCUPANCY
Occupied when
Closed or
Unoccupied when
Open
Normal Open (1)
Open and
Unoccupied
Closed and
Occupied
Occupied when Open Normal Closed (2)
Open and
Occupied
Unoccupied when
Closed
Normal Closed (2)
Closed and
Occupied
IMPORTANT: To perform remote occupancy, an Economizer
Control Board must be installed in the unit.
Level 3 Priority
The following occupancy options are determined by the state of
Occupancy Schedule Number
(Configuration→CCN→SCH.O→SCH.N) and the Global
Schedule Broadcast (Configuration→CCN→BROD→B.GS).
1. (Configuration→CCN→SCH.O→SCH.N = 0) The unit is
always considered occupied and the programmed schedule
is ignored. This is the factory default.
2. (Configuration→CCN→SCH.O→SCH.N = 1-64) Follow
the local programmed schedule. Schedules 1 to 64 are local
within the controller. The 48/50PD unit can only store one
local schedule and therefore changing this number only
changes the title of the schedule table.
3. (Configuration→CCN→SCH.O→SCH.N = 65-99)
Follow the global programmed schedule. If the 48/50PD
unit is configured as a Global Schedule Broadcaster
(Configuration→CCN→ROD→B.GS = YES), the unit
will follow the unit’s programmed schedule and broadcast
the schedule so that other devices programmed to follow
this schedule number can receive the schedule. If the
48/50PD unit is not programmed as a Global Schedule
Broadcaster
(Configuration→CCN→BROD→B.GS = NO), the unit
will receive broadcasted schedules from the unit
programmed to broadcast this schedule number. While
using the programmed schedule, occupancy can be
temporarily switched from unoccupied to occupied by
pressing the override button for approximately 3 seconds on
the T--55, T --56, T--58 or T --59 space temperature sensor.
Override will only occur if SPT Override Enabled
48/50PD