Table of Contents
Advertisement
NOTE: The enthalpy control must be set to the "D" setting for
differential enthalpy control to work properly.
The enthalpy control receives the indoor and return enthalpy from
the outdoor and return air enthalpy sensors and provides a dry
contact switch input to the PremierLink™ controller. Locate the
controller in place of an existing economizer controller or near the
actuator. The mounting plate may not be needed if an existing
bracket is used.
A closed contact indicates that outside air is preferred to the return
air. An open contact indicates that the economizer should remain
at minimum position.
To wire the outdoor air enthalpy sensor, perform the following
(see Fig. 4 and 23):
NOTE: The outdoor air sensor can be removed from the back of
the enthalpy controller and mounted remotely.
1.
Use a 4-conductor, 18 or 20 AWG (American Wire Gage)
cable to connect the enthalpy control to the PremierLink
controller and power transformer.
2.
Connect the following 4 wires from the wire harness located
in rooftop unit to the enthalpy controller:
a. Connect the BRN wire to the 24 vac terminal (TR1) on
enthalpy control and to pin 1 on 12-pin harness.
b. Connect the RED wire to the 24 vac GND terminal (TR)
on enthalpy sensor and to pin 2 on 12-pin harness.
c. Connect the ORN/GRAY wire to J4-2 on PremierLink
controller and to terminal 3 on enthalpy sensor.
d. Connect the RED/GRAY wire to J4-1 on PremierLink
controller and to terminal 2 on enthalpy sensor.
NOTE: If installing in a Carrier rooftop, use the two gray wires
provided from the control section to the economizer to connect
PremierLink controller to terminals 2 and 3 on enthalpy sensor. If
NOT using Carrier equipment, wires may need to be
field-supplied and installed.
RETURN AIR ENTHALPY SENSOR (HH57AC078)
Mount the return air enthalpy sensor (HH57AC078) in the return
air duct. The return air sensor is wired to the enthalpy controller
(HH57AC077) (see Fig. 25 and 26). The outdoor enthalpy
changeover set point is set at the controller.
To wire the return air enthalpy sensor, perform the following (see
Fig. 26):
1.
Use a 2-conductor, 18 or 20 AWG, twisted pair cable to con-
nect the return air enthalpy sensor to the enthalpy controller.
2.
At the enthalpy control remove the factory-installed resistor
from the (SR) and (+) terminals.
3.
Connect the field-supplied RED wire to (+) spade connector
on the return air enthalpy sensor and the (SR+) terminal on
the enthalpy controller. Connect the BLK wire to (S) spade
connector on the return air enthalpy sensor and the (SR) ter-
minal on the enthalpy controller. (See Fig. 26.)
24VAC TR
TR1
HOT
COM
B
C
S
O
A
D
H570A ENTHALPY CONTROL
S
TR
24 VAC
R
1
CONTACTS SHOWN IN HIGH ENTHALPY
OR UNPOWERED STATE.
CONTACT RATINGS: 1.5A RUN, 3.5A IN
RUSH AT 24 VAC 3mA MIN. AT 11VDC
3
CW-SETPOINTS-CCW
D C B A
%
90
2
1
H
70
U
M
50
I
D
30
I
10
T
50 55 60 65 70 75 80 85
Y
OUTDOOR TEMP.
HH57AC078 Enthalpy
Sensor (Used With
Enthalpy Control
For Differential
Enthalpy Operation)
Fig. 25 — Enthalpy Control, Sensor and Mounting
ENTHALPY CONTROLLER
B
TR
TR1
C
A
D
+
SO
+
SR
3
2
1
LED
Fig. 26 — Outdoor and Return Air Enthalpy Sensor
NOTE: Remove factory-installed jumper across SE and + before
connecting wires from return air enthalpy sensor. Switches are
shown in high outdoor air enthalpy state. Terminals 2 and 3 close
on low outdoor air enthalpy relative to indoor air enthalpy. Re-
move sensor mounted on back of control and locate in outside air-
stream.
ENTHALPY SWITCH/RECEIVER (33CSENTHSW)
The accessory enthalpy switch/receiver (33CSENTHSW) senses
temperature and humidity of the air surrounding the device and
calculates the enthalpy when used without an enthalpy sensor. The
relay is energized when enthalpy is high and de-energized when
enthalpy is low (based on ASHRAE 90.1 [American Society of
Heating, Refrigeration and Air Conditioning Engineers] criteria).
If an accessory enthalpy sensor (33CSENTSEN) is attached to the
return air sensor input, then differential enthalpy is calculated. The
relay is energized when the enthalpy detected by the return air
enthalpy sensor is less than the enthalpy at the enthalpy switch/
receiver. The relay is de-energized when the enthalpy detected by
the return air enthalpy switch/receiver (differential enthalpy con-
trol). (See Fig. 27 and 28.)
11
HH57AC077
Enthalpy
Control And
Bracket
TR1
2
3
Outdoor Air
Enthalpy Sensor
DAMPER
CLOSDER
°F
Mounting Plate
Plate
S
RED
BRN
+
BLK
RED
S
(RETURN AIR
+
GRAY/ORN
WIRE HARNESS
IN UNIT
GRAY/RED
Wiring
+
S
(OUTDOOR
AIR
ENTHALPY
SENSOR)
ENTHALPY
SENSOR)
Advertisement
Table of Contents
