Carrier 50LC 07, Service And Maintenance Instructions, Page: 60 / 100

60
Menu 3: Setpoints
Parameter
Project
Value
Parameter
Default
Value
Parameter
Range and Increment
Notes
MAT SET 53
_
F
(12
_
C)
38 to 65
_
F;
(3 to 18
_
C)
increment by 1
_
SUPPLY AIR SETPOINT
Setpoint determines where the economizer will modulate the OA
damper to maintain the supply air temperature.
See Menu Note 2 (on page 44).
LOW T LOCK 32
_
F
(0
_
C)
---45 to 80
_
F
(---43 to 27
_
C)
increment by 1
_
COMPRESSOR LOW TEMPERATURE LOCKOUT
Setpoint determines outdoor temperature when the mechanical
cooling cannot be turned on.
DRYBLB SET 63
_
F
(17
_
C)
48 to 80
_
F;
(9 to 27
_
C)
increment by 1
_
OA DRY BULB TEMPERATURE CHANGEOVER SETPOINT
Setpoint determines where the economizer will assume outdoor air
temperature is good for free cooling; e.g.: at 63
_
F (17
_
C), unit will
economize at 62
_
F (16.7
_
C) and below and not economize at 64
_
F
(17.8
_
C) and above. There is a 2
_
F (1.1
_
C) deadband.
See Menu Note 3 (on page 44).
ENTH CURVE ES3 ES1, ES2, ES3, ES4,
or ES5
ENTHALPY CHANGEOVER CURVE
(Requires enthalpy sensor option)
Enthalpy boundary “curves” for economizing using single enthalpy.
DCV SET 1100ppm 500 to 2000 ppm;
increment by 100
DEMAND CONTROL VENTILATION SETPOINT
Displays only if CO
2
sensor is connected. Setpoint for Demand Control
Ventilation of space. Above the setpoint, the OA dampers will modulate
open to bring in additional OA to maintain a space ppm level below
the setpoint.
MIN POS L 6.0 V 2 to 10Vdc VENTILATION MINIMUM POSITION AT LOW SPEED
Displays ONLY if a CO2 sensor is NOT connected.
MIN POS H 4.4 V 2 to 10Vdc VENTILATION MINIMUM POSITION AT HIGH SPEED
Displays ONLY if a CO2 sensor is NOT connected.
VENTMAX L 6.0 V 2 to 10Vdc DCV MAXIMUM DAMPER POSITION AT LOW SPEED
(Requires CO
2
sensor connected)
VENTMAX H 4.4 V 2 to 10Vdc DCV MAXIMUM DAMPER POSITION AT HIGH SPEED
(Requires CO
2
sensor connected)
VENTMIN L 3.7 V 2 to 10Vdc DCV MINIMUM DAMPER POSITION AT LOW SPEED
(Requires CO
2
sensor connected)
VENTMIN H 2.8 V 2 to 10Vdc DCV MINIMUM DAMPER POSITION AT HIGH SPEED
(Requires CO
2
sensor connected)
ERV OAT SP 32
_
F
(0
_
C)
0 to 50
_
F;
(---18 to 10
_
C)
increment by 1
_
ENERGY RECOVERY VENTILATION UNIT OUTDOOR AIR
TEMPERATURE SETPOINT
Only when AUX1 O = ERV
EXH1 L SET 65% 0 to 100%;
increment by 1
EXHAUST FAN STAGE 1 SETPOINT AT LOW SPEED
Setpoint for OA damper position when exhaust fan1 is powered by the
economizer.
EXH1 H SET 50% 0 to 100%;
increment by 1
EXHAUST FAN STAGE 1 SETPOINT AT HIGH SPEED
Setpoint for OA damper position when exhaust fan1 is powered by the
economizer.
EXH2 L SET 80% 0 to 100%;
increment by 1
EXHAUST FAN STAGE 2 SETPOINT AT LOW SPEED
Setpoint for OA damper position when exhaust fan 2 is powered by
the economizer.
Only used when AUX1---O is set to EHX2.
EXH2 H SET 75% 0 to 100%;
increment by 1
EXHAUST FAN STAGE 2 SETPOINT AT HIGH SPEED
Setpoint for OA damper position when exhaust fan 2 is powered by
the economizer.
Only used when AUX1---O is set to EHX2.
Staged Air Volume (SAV
t
) with Variable
Frequency Drive
The Staged Air Volume (SAV) system utilizes a Variable
Frequency Drive (VFD) to automatically adjust the indoor
fan motor speed in sequence with the unit’s ventilation,
cooling and heating operation. Per ASHRAE 90.1 2010
standard section 6.4.3.10.b, during the first stage of
cooling operation the SAV system will adjust the fan
motor to provide two--thirds (2/3) of the design airflow
rate for the unit. When the call for the second stage of
cooling is required, the SAV system will allow the design
airflow rate for the unit established (100%). During the
heating mode, the SAV system will allow total design
airflow rate (100%) operation. During ventilation mode,
the SAV system will operate the fan motor at 2/3 speed.