Bryant 548J - Manual (Page 36)

36
Table 14 – RTU--MP Controller Inputs and Outputs
POINT NAME
BACnet OBJECT
NAME
TYPE OF I/O
CONNECTION PIN
NUMBERS
INPUTS
Space Temperature Sensor sptsens AI (10K Thermistor) J20---1, 2
Supply Air Temperature sat AI (10K Thermistor) J2---1, 2
Local Outside Air Temperature Sensor oatsens AI (10K Thermistor) J2---3, 4
Space Temperature Offset Pot sptopot AI (100K Potentiometer) J20---3
Indoor Air Quality iaq AI (4---20 ma) J4---2, 3
Outdoor Air Quality oaq AI (4---20 ma) J4---5, 6
Safety Chain Feedback safety DI (24 VAC) J1---9
Compressor Safety compstat DI (24 VAC) J1---2
Fire Shutdown firedown DI (24 VAC) J1---10
Enthalpy Switch enthalpy DI (24 VAC) J2---6, 7
Humidistat Input Status humstat DI (24 VAC) J5---7, 8
CONFIGURABLE INPUTS*
Space Relative Humidity sprh AI (4---20 ma)
J4---2,3 or J4---5,6
Outside Air Relative Humidity oarh AI (4---20 ma)
Supply Fan Status fanstat DI (24 VAC)
J5---1,2 or J5---3,4 or
J5 5,6 or J5---7,8
Filter Status filtstat DI (24 VAC)
Remote Occupancy Input remocc DI (24 VAC)
OUTPUTS
Economizer Commanded Position econocmd 4---20ma J2---5
Supply Fan Relay State sf DO Relay (24VAC , 1A) J1---4
Compressor 1 Relay State comp_1 DO Relay (24VAC , 1A) J1---8
Compressor 2 Relay State comp_2 DO Relay (24VAC , 1A) J1---7
Heat Stage 1 Relay State heat_1 DO Relay (24VAC , 1A) J1---6
Heat Stage 2 Relay State heat_2 DO Relay (24VAC , 1A) J1---5
Power Exhaust Relay State aux_2 DO Relay (24VAC , 1A) J11---3
Dehumidification Relay State humizer DO Relay (24VAC, 1A) J11---7, 8
LEGEND
AI --- Analog Input
AO --- Analog Output
DI --- Discrete Input
DO --- Discrete Output
* These inputs (if installed) take the place of the default input on the specific channel according to schematic.
Parallel pins J5---1 = J2---6, J5---3 = J1---10, J5---5 = J1---2 are used for field---installation.
Refer to the input configuration and accessory sections for more detail.
The RTU--MP controller requires the use of a Bryant
space sensor. A standard thermostat cannot be used with
the RTU--MP system.
Supply Air Temperature (SAT) Sensor — On
FIOP--equipped 548J unit, the unit is supplied with a
supply--air temperature (SAT) sensor (33ZCSENSAT).
This sensor is a tubular probe type, approx 6--inches
(153 mm) in length. It is a nominal 10--k ohm thermistor.
See Table 15 for temperature--resistance characteristic.
The SAT is factory--wired. The SAT probe is wire--tied to
the supply--air opening (on the horizontal opening end) in
its shipping position. Remove the sensor for installation.
Re--position the sensor in the flange of the supply--air
opening or in the supply air duct (as required by local
codes). Drill or punch a 1 /
2
--in. (12.7 mm) hole in the
flange or duct. Use two field--supplied, self--drilling
screws to secure the sensor probe in a horizontal
orientation. See Fig. 49.
SUPPLY AIR RETURN AIR
SUPPLY AIR
TEMPERATURE
SENSOR ROOF
CURB
C08200
Fig. 49 -- Typical Mounting Location for Supply Air
Temperature (SAT) Sensor on Small Rooftop Units
548J