63
VCCX2 Controller Technical Guide
Entering Air Temperature
Sensor
Reset In 0-10 VDC
GND
+
-
Emergency
Shutdown
Line
GND
40 VA
transformer
minimum
Heat 1 Relay
Heat 2 Relay
Heat 3 Relay
Heat 4 Relay
Heat 5 Relay
Heat 6 Relay
Relay
Contact
PWM SSR
+
Modulating SCR
(0-10 VDC)
+
Leaving Air 2
Temperature Sensor
Leaving Air 1
Temperature Sensor
SAFETIES
(by others)
N.C.
Heat Enable
Signal (24 VAC)
W1
Mount inside PREHEAT-X
box wall
Mount inside PREHEAT-X
box wall
EBC E-BUS cable connects to
the VCCX2 Controllers Expansion Port
18-30
VAC
Make splice
connections inside
sensor enclosure as
shown. Seal all
conduit fittings with
Silicone sealant.
Mount sensor outdoors in a
shaded protected area and
in the upright position as
shown.
Note:
Reset In and Heat Enable
Inputs are used in Stand-Alone
Mode only.
Note:
All relay outputs are normally open
and rated for 24 VAC only.
1 amp maximum load.
Figure 44: PREHEAT-X to VCCX2 Controller Wiring
PREHEAT-X and PREHEAT-X-EXT
Controller Wiring
The ASM01688 PREHEAT-X and ASM01689 PREHEAT-X-
EXT are designed to control fixed stages of Preheat and optional
modulating Preheat to maintain a desired Preheat Leaving Air
Temperature Setpoint. The PREHEAT-X is limited to a 35°F
Leaving Air Temperature Setpoint. The PREHEAT-X-EXT has
an extended Leaving Air Temperature Setpoint range down to
0°F. It should only be used with the approval of AAON.
Either PREHEAT-X directly connects to the VCCX2 Controller
or indirectly using an E-BUS Expansion Board via an E-BUS
cable. See
Figure 44, this page
for wiring.
The following information will be passed between either
PREHEAT-X and the VCCX2 Controller:
•
Leaving Air Temperature Setpoint
•
Entering Air Temperature Setpoint
•
Preheat Enable Signal
•
Leaving Air Temperature Status
•
Entering Air Temperature Status
•
Alarm Status
•
If the communication is interrupted between the
PREHEAT-X and the VCCX2 Controller, the
PREHEAT-X will be disabled.
For more information, refer to the
PREHEAT-X
or
PREHEAT-
X-EXT Technical Guide
.
WIRING
PREHEAT-X and PREHEAT-X-EXT