Carrier 48/50AJ specifications

Variable Air Volume Units Using Return Air Sensor or Space Temperature Sensor — To con-

figure the unit, perform the following:

1.The type of control is configured under Configuration →UNIT→C.TYP. Set C.TYP to 1 (VAV-RAT) for return air sensor. Set C.TYP to 2 (VAV-SPT) for space tempera- ture sensor.

NOTE: For VAV with a space sensor (VAV-SPT), under Configuration→UNIT→SENS→SPT.S, enable the space sensor by setting SPT.S to ENBL.

2.Install jumpers between R-W2 and W2-W1 on TB4 in the control box.

3.The space temperature set points and the supply air set points are configured under the Setpoints menu. The heating and cooling set points must be configured. See the Heating Control and Cooling Control sections for further description on these configurations. Configure the following set points:

OHSP Occupied Heat Setpoint

OCSP Occupied Cool Setpoint

UHSP Unoccupied Heat Setpoint

V.C.ON VAV Occupied Cool On Delta

V.C.OF VAV Occupied Cool Off Delta

SASP Supply Air Setpoint

4.To program time schedules, make sure SCH.N=1 under Configuration→CCN→SC.OV→SCH.N to configure the control to use local schedules.

5.Under the Timeclock→SCH.L submenu, enter the de- sired schedule. See Time Clock Configuration section on page 75 for further description of these configurations.

6.Under Configuration→SP→SP.SP, the supply duct Stat- ic Pressure Setpoint should be configured.

SP.SP Static Pressure Setpoint

7.If supply air temperature reset is desired, under the Configuration→EDT.R submenu, the following set points should be configured:

RS.CF EDT Reset Configuration RTIO Reset Ratio (if RS.CF = 1 or 2) LIMT Reset Limit (if RS.CF = 1 or 2)

RES.S EDT 4-20 mA Reset Input (if RS.CF = 3)

NOTE: Configure either RTIO and LIMT or RES.S. All three are not used.

8.See the Economizer Options section on this page for ad- ditional economizer option configurations.

9.See the Exhaust Options section on page 29 for additional exhaust option configurations.

Multi-Stage Constant Volume Units with Mechanical Thermostat — To configure the unit, per- form the following:

1.Under Configuration→UNIT→C.TYP, set C.TYP to 3 (TSTAT MULTI).

2.Remove jumpers from R-W2 and W2-W1 on TB4 in the control box. Connect thermostat to TB4.

3.Under the Setpoints menu, set the following configurations:

SA.HI Supply Air Set Point Hi

SA.LO Supply Air Set Point Lo

4.See the Economizer Options section on this page for ad- ditional economizer option configurations.

5.See the Exhaust Options section on page 29 for additional exhaust option configurations.

Multi-Stage Constant Volume Units with Space Sensor — To configure the unit, perform the following:

1.Under Configuration→UNIT→C.TYP, set C.TYP to 5 (SPT MULTI).

2.Install jumpers between R-W2 and W2-W1 on TB4 in the control box.

3.Under the Setpoints menu, the following configurations should be set:

OHSP Occupied Heat Setpoint

OCSP Occupied Cool Setpoint

UHSP Unoccupied Heat Setpoint

UCSP Unoccupied Cool Setpoint

GAP Heat-Cool Setpoint Gap

SA.HI Supply Air Set Point Hi

SA.LO Supply Air Set Point Lo

4.The degrees of demand from the space temperature set points are configured under the Configuration→D.LV.T submenu. See the Heating Control and Cooling Control sections for further description on these configurations. Configure the following set points:

L.H.ON Demand Level Lo Heat On

H.H.ON Demand Level Hi Heat On

L.H.OF Demand Level Lo Heat On

L.C.ON Demand Level Lo Cool On

H.C.ON Demand Level Hi Cool On

L.C.OF Demand Level Lo Cool On

5.Under Configuration→UNIT→SENS→SPT.S, enable the space sensor by setting SPT.S to ENBL.

6.Under Configuration→UNIT→CV.FN, set CV.FN to 1 for continuous fan or 0 for automatic fan.

7.To program time schedules, set SCH.N=1 under Config- uration→CCN→SC.OV→SCH.N to configure the con- trol to use local schedules.

8.Under the Timeclock→SCH.L submenu, enter the de- sired schedule. See Time Clock Configuration section on page 75 for further description of these configurations.

9.See the Economizer Options section below for additional economizer option configurations.

10.See the Exhaust Options section on page 29 for additional exhaust option configurations.

Economizer Options — Under the Configuration→ ECON submenu, the following set points may be configured:

EC.EN Economizer Enabled? EC.MN Economizer Min.Position EC.MX Economizer Maximum Position E.TRM Economizer Trim for SumZ? E.SEL Econ Changeover Select OA.E.C OA Enthalpy Change Over Select OA.EN Outdoor Enthalpy Compare Value OAT.L High OAT Lockout Temp O.DEW OA Dew Point Temp Limit ORH.S Outside Air RH Sensor

Configuration→ECON→EC.MN should always be set for

the minimum damper position.

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