Table of Contents
Advertisement
DIFFERENTIAL ENTHALPY CONTROL — Differen-
tial enthalpy control is provided by sensing and comparing the
outside air and return air enthalpy conditions. Install the out-
door air enthalpy control as described above. Add and install a
return air enthalpy sensor.
RETURN AIR ENTHALPY SENSOR — Mount the re-
turn-air enthalpy sensor (33CSENTSEN) in the return-air sec-
tion of the economizer. The return air sensor is wired to the en-
thalpy controller (33CSENTHSW). See Fig. 62.
24V
– 4-20
MAIN
GND
+ VDC
OUT
LOW
OUTSIDE AIR
ENTHALPY SWITCH
+ 24-36
VDC IN
– 4-20 MAIN
OUT
Fig. 62 — Outside and Return Air Enthalpy Sensor
Wiring
To wire the return air enthalpy sensor, perform the follow-
ing:
1. Use a 2-conductor, 18 or 20 AWG, twisted pair cable to
connect the return air enthalpy sensor to the enthalpy con-
troller.
2. Connect the field-supplied RED wire to (+) spade con-
nector on the return air enthalpy sensor and the (+) termi-
nal on the enthalpy controller. Connect the BLK wire to
(–) spade connector on the return air enthalpy sensor and
the (
) terminal on the enthalpy controller.
–
Smoke Detectors —
Smoke detectors are available as fac-
tory-installed options on 581J models. Smoke detectors may be
specified for Supply Air only or for Return Air without or with
economizer or in combination of Supply Air and Return Air.
All components necessary for operation are factory-provided
and mounted. The unit is factory-configured for immediate
smoke detector shutdown operation; additional wiring or modi-
fications to unit terminal board may be necessary to complete
STEP 1
RED
PL6-1 (24-V)
BLK
PL6-4 (COM)
CTB ECON
GRA
7
(P'LINK: to J4-2) or
(RTU Open: to J2-6)
RETURN AIR
ENTHALPY
SENSOR
Fig. 64 — Completing Installation of Return Air Smoke Sensor
the unit and smoke detector configuration to meet project re-
quirements.
Units equipped with factory-optional Return Air smoke de-
tectors require a relocation of the sensor module at unit installa-
tion. See Fig. 63 for the as shipped location.
Completing Installation of Return Air Smoke Sensor:
1. Unscrew the two screws holding the Return Air Smoke
Detector assembly. See Fig. 64, Step 1. Save the screws.
2. Turn the assembly 90 and then rotate end to end. Make
sure that the elbow fitting is pointing down. See Fig. 64,
Step 2.
3. Screw the sensor and detector plate into its operating po-
sition using screws from Step 1. See Fig. 64, Step 3.
4. Connect the flexible tube on the sampling inlet to the
sampling tube on the basepan.
RETURN AIR
SMOKE DETECTOR
(AS SHIPPED)
Fig. 63 — Return Air Smoke Detector, Shipping
ADDITIONAL APPLICATION DATA — Refer to the
Application Data sheet titled Factory Installed Smoke Detec-
tors for Small and Medium Rooftop Units 2 to 25 Tons for dis-
cussions on additional control features of these smoke detec-
tors including multiple unit coordination.
STEP 2
46
Position
STEP 3
Advertisement
Table of Contents
