70
Dehumidification Configuration (
D.SEL
) — The dehumidi-
fication configuration can be set for the following settings:
•
D.SEL
= 0 – (NO DEHUMIDIFY) – No dehumidifica-
tion and reheat.
•
D.SEL
= 1 – (DH - ST.GAS) – The control will perform
dehumidification and reheat with staged gas only.
•
D.SEL
= 2 – (DH - RELAY) – The control will perform
both dehumidification and reheat with third party heat
via an alarm relay. In the case of
D.SEL
=2, during dehu-
midification, the alarm relay will close to convey the
need for “re-heat.” A typical application might be to
energize a 3-way valve to perform DX reheat.
•
D.SEL
= 3 – (DH - HUMDZR) – The control will use
the Humidi-MiZer
®
adaptive dehumidification system.
• This configuration shall have a range of 0 to 3 with
default of 0.
Dehumidification Sensor (
D.SEN
) — The sensor can be con-
figured for the following settings:
•
D.SEN
= 1 — Initiated by return air relative humidity
sensor.
•
D.SEN
= 2 — Initiated by discrete input.
Economizer Disable in Dehum Mode (
D.EC.D
) — This
configuration determines economizer operation during Dehu-
midification mode. This configuration shall have a range of 1-2
with default of 1.
The RARH Sensor and discrete input utilized must be com-
patible with the
Comfort
LINK hardware and software.
•
D.EC.D
= YES — Economizer disabled during dehu-
midification (default).
•
D.EC.D
= NO — Economizer not disabled during dehu-
midification.
Vent Reheat Setpoint Select (
D.V.CF
) — This configuration
determines how the vent reheat setpoint is selected.
•
D.V.CF
= 0 — Reheat follows an offset subtracted from
return air temperature (
D.V.RA
).
•
D.V.CF
= 1 — Reheat follows a dehumidification heat
setpoint (
D.V.HT
).
Vent Reheat RAT Offset (
D.V.RA
) — Setpoint offset used
only during the vent mode. The air will be reheated to return-
air temperature less this offset. This configuration shall have a
range of 0 to 8 F with default of 0.
Vent Reheat Setpoint
(
D.V.HT
) — Setpoint used only during
the vent mode. The air will be reheated to this setpoint. This
configuration shall have a range of 55 to 95 with default of 70.
Dehumidify Cool Setpoint (
D.C.SP
) — This is the dehumid-
ification cooling setpoint. This configuration shall have a range
of 40 to 55 with default of 45.
Dehumidity RH Setpoint (
D.RH.S
) — This is the dehumidi-
fication relative humidity trip point. This configuration shall
have a range of 10 to 90 with default of 55.
Enable Hmzr St Oil Ret (
HZ.OR
) — [ENHORTST] This
configuration can enable or disable the Humidi-MiZer oil
return during service test. It is recommended leaving this con-
figuration enabled.
This configuration shall have a range of DSLB/ENBL with
default of ENBL.
OPERATION — Dehumidification and reheat can only occur
if the unit is equipped with either staged gas or hydronic heat.
Dehumidification without reheat can be done on any unit but
Configuration
DEHU
D.SEL
must be set to 2.
If the machine’s control type is a TSTAT type (
Configura-
tion
UNIT
C.TYP
=3 or 4) and the discrete input selection
for the sensor is not configured (
D.SEN
not equal to 2),
dehumidification will be disabled. It shall not be possible to
perform dehumidification using the return air relative humidity
sensor when configured for TSTAT operation.
If the machine’s control type is a TSTAT type (
Configura-
tion
UNIT
C.TYP
=3 or 4) and the economizer is able to
provide cooling, a dehumidification mode may be called out,
but the control will not request mechanical cooling and
D.EC.D
=NO.
NOTE: Configuring
Configuration
DEHU
D.SEN
to 1
(RARH SENSOR) will enable the ECB1 board along with the
sensor selected for control.
NOTE: Configuring
Configuration
DEHU
D.SEN
to 2
(DISCR.INPUT) will enable the CEM board along with the
switch input for control.
NOTE: Configuring
Configuration
DEHU
D.SEL
to 3
(DH-HMZR) will enable the EXB2/RXB board with the CCT
input and three-way valve in addition to the EXV board with
the modulating valves.
If an associated RARH sensor responsible for dehumidifi-
cation fails, dehumidification will not be attempted, see Alert
T078 Return Air Relative Humidity Sensor Fail.
If an associated sensor responsible for dehumidification
fails, dehumidification will not be attempted (
SPRH
,
RARH
).
Initiating a Reheat or Dehumidification Mode — To call out
a Reheat mode in the Vent or the Off HVAC mode, or to call
out a Dehumidification mode in a Cool 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 dehumidifica-
tion mode is initiated, the rooftop will attempt to lower
humidity as follows:
• Economizer Cooling — The economizer, if allowed to
perform free cooling, will have its control point (
Run
Status
VIEW
EC.C.P
) set to
Configuration
DEHU
D.C.SP
. If
Configuration
DEHU
D.EC.D
is disabled, the economizer will always be disabled
during dehumidification.
Table 70 — Dehumidification Configuration
ITEM
EXPANSION
RANGE
UNITS
CCN POINT
DEFAULT
DEHU
DEHUMIDIFICATION CONFIG.
D.SEL
Dehumidification Config
0-3
DHSELECT
0
D.SEN
Dehumidification Sensor
1-2
DHSENSOR
1
D.EC.D
Econ disable in DH mode?
Yes/No
DHECDISA
Yes
D.V.CF
Vent Reheat Setpt Select
0-1
DHVHTCFG
0
D.V.RA
Vent Reheat RAT offset
0-8
^F
DHVRAOFF
0
D.V.HT
Vent Reheat Setpoint
55-95
dF
DHVHT_SP
70
D.C.SP
Dehumidify Cool Setpoint
40-55
dF
DHCOOLSP
45
D.RH.S
Dehumidify RH Setpoint
10-90
%
DHRELHSP
55
HZ.RT
Humidi-MiZer Adjust Rate
5-120
sec
HMZRRATE
30
HZ.PG
Humidi-MiZer Prop. Gain
0-10
HMZR_PG
0.8
HZ.OR
Enable HMZR St Oil Ret
Dsbl/Enbl
ENHORTST
Enbl
Содержание Carrier Weathermaker 48A2
Страница 105: ...105 Fig 20 Typical Main Control Box Wiring Schematic 48 50A2 A3 A4 A5 Units...
Страница 106: ...106 Fig 21 Typical Auxiliary Control Box Wiring Schematic...
Страница 107: ...107 Fig 22 Typical 2 Stage Gas Heat Wiring Schematic Size 060 Units Shown a48 8357...
Страница 108: ...108 TO NEXT PAGE Fig 23 Typical Staged Gas Heat Wiring Schematic Size 060 Units Shown A48 7296...
Страница 109: ...109 Fig 23 Typical Staged Gas Heat Wiring Schematic Size 060 Units Shown cont A48 8358...
Страница 110: ...110 Fig 24 Typical Electric Heat Control Schematic 50 Series Size 060 Units Shown a50 8228...
Страница 111: ...111 Fig 25 Typical Power Schematic 48 50A2 A3 A4 A5 060 Unit Shown...
Страница 112: ...112 Fig 26 Typical Low Ambient Controls Option Wiring...
Страница 113: ...113 Fig 27 Typical Small Chassis Component Location Size 020 035 Units...
Страница 114: ...114 Fig 28 Typical Large Chassis Component Locations Size 040 060 Units...
Страница 118: ...118 Fig 30 Economizer Control Board ECB1 and VAV Control Board ECB2 A48 7706...
Страница 142: ...142 A48 3733 Fig 56 Main Burner Removal...
Страница 176: ...176 APPENDIX C VFD INFORMATION cont Fig F Internal Enclosure Fan Replacement A48 7716...