Carrier Weathermaster 48P030-100 Controls, Start-Up, Operation, Service, And Troubleshooting page 93

ITEM
DEHU DEHUMIDIFICATION CONFIG.
D.SEL Dehumidification Config
D.SEN Dehumidification Sensor
D.EC.D Econ disable in DH mode?
D.V.CF Vent Reheat Setpt Select
D.V.RA Vent Reheat RAT offset
D.V.HT Vent Reheat Setpoint
D.C.SP Dehumidify Cool Setpoint
D.RH.S Dehumidify RH Setpoint
HZ.RT Humidi-MiZer Adjust Rate
HZ.PG Humidi-MiZer Prop. Gain
DH.DB Dehumidify RH Deadband
DH.TG Dehumidification Discrete Timeguard
Table 73 — Dehumidification Heat Source Dependency upon Heating Stages
HT.CF (HEATTYPE)
Heating provided by the system
0–5 any
0–5 any
0–5 any
0 No heat
1 2-stage electric heat
2 2-stage gas heat
3 Staged or mod gas heat
4 Hydronic
5 SCR electric
LEGEND
DHSELECT — Dehumidification Heat Source
HEATTYPE — Heating Type
HTSTGTYP — Heating Stage Type
Vent Reheat RAT Offset (D.V.RA)
Set point offset used only during the vent mode. The air will be re-
heated to return-air temperature less this offset.
Vent Reheat Set Point (D.V.HT)
Set point used only during the vent mode. The air will be reheated
to this set point.
Dehumidify Cool Set Point (D.C.SP)
This is the dehumidification cooling set point.
Dehumidity RH Set Point (D.RH.S)
This is the dehumidification relative humidity trip point.
Dehumidify RH Deadband (DH.DB)
This is the control deadband for the RH control.
Dehumidify Discrete Timeguard (DH.TG)
This is the amount of time that the discrete input humidity sensor
(D.SEN=3) must remain OFF before the dehumidification mode
is disabled.
OPERATION
Dehumidification can occur on all P series units. However, dehu-
midification with reheat (Venting Dehum, Cooling Dehum or
Heating Dehum) can only occur if the unit is equipped with one of
the following types of heat: Multi-Staged or Modulating Gas, Hy-
dronic heat, third-party Heat or Humidi-MiZer. Dehumidification
without reheat (D.SEL=5) will only operate in Venting Dehum or
Cooling Dehum. See Humidi-MiZer Adaptive Dehumidification
System section on page 94 for details on the operation of the Hu-
midi-MiZer system for dehumidification and reheat. If the ma-
chine's control type is a TSTAT type (Configuration
C.TYP=3) and the discrete input selection for the sensor is not
configured (D.SEN not equal to 3), dehumidification will be
disabled.
Table 72 — Dehumidification Configuration
EXPANSION
0 to 4
1 to 3
Yes/No
0 to 1
0 to 8
55 to 95
40 to 55
10 to 90
5 to 120
0 to 10
1 to 30
10 to 90
HT.ST
HTSTGTYP
N/A
N/A
N/A
N/A
N/A
0
0–5
N/A
6, 7, 8
  
UNIT
RANGE UNITS
DHSELECT
DHSENSOR
DHECDISA
DHVHTCFG
deltaF DHVRAOFF
dF DHVHT_SP
dF DHCOOLSP
% DHRELHSP
sec HMZRRATE
HMZR_PG
% DHSENSDB
seconds DHDISCTG
D.SEL (DHSELECT)
Selected Heat for Dehum
0 None
4 Humidi-MiZer
5 Dehum without reheat
3 3rd party heat
5 Dehum without reheat
5 Dehum without reheat
2 Stage or mod gas
1 Hydronic
5 Dehum without reheat
If the machine's control type is a TSTAT type (Configura-
 
tion UNIT C.TYP=3) and the economizer is able to provide
cooling, a dehumidification mode may be called out, but the con-
trol will not request mechanical cooling.
NOTE: Configuring Configuration
3 will enable the CEM board along with the sensor selected for
control.
NOTE: If Configuration
staged gas or hot water valve control will be automatically enabled

(Configuration HEAT
If a tempering, unoccupied, or "mechanical cooling locked out"
HVAC mode is present, dehumidification will be disabled. An
HVAC: Off, Vent or Cool mode must be in effect to launch either a
Heat or Dehumidification mode.
If an associated sensor responsible for dehumidification fails, de-
humidification will not be attempted (SPRH, RARH).
Initiating a Dehumidification Mode
To call out a Dehumidification mode in the Off, Vent, Cool, or
Heat HVAC mode, one of the following conditions must be true:
• The space is occupied and the humidity is greater than the
relative humidity trip point (D.RH.S).
• The space is occupied and the discrete humidity input is
closed.
Dehumidification and Reheat Control
If a dehumidification mode is initiated, the rooftop will attempt to
lower humidity as follows:
• Economizer Cooling — The economizer, if allowed to per-
form free cooling, will have its control point (Run Sta-
 
tus VIEW EC.C.P) set to Configuration
D.C.SP. If Configuration
economizer will always be disabled during dehumidification.
93
CCN POINT DEFAULT
0
1
Yes
0
0
70
45
55
30
0.8
5
30
DEHUM
ALLOWED ALLOWED
No
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
 
DEHU D.SEN to 1, 2 or
 
DEHU D.SEL = 1 or 2, then either

HT.CF will be set to either 3 or 4).
 
DEHU D.EC.D is disabled, the
REHEAT
No
Yes
No
Yes
No
No
Yes
Yes
No
  
DEHU