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Two Condenser Head Pressure II Module Technical Guide
4
OVERVIEW
Overview
The Two Condenser Head Pressure II Module (ASM01891)
monitors four individual head pressure transducers and controls
two Condenser Fans or Water Valves on units with two physically
separate condenser sections. The highest reading of head pressure
transducers 1 & 2 controls Condenser Signal A. The highest
reading of head pressure transducers 3 & 4 controls Condenser
Signal B. If this is a heat pump unit, the module is able to detect
when the unit is in Heat Pump Heating mode and will force the
condenser signal to 100% until it leaves this mode.
The Two Condenser Head Pressure II Module is designed to work
stand-alone by using its OPTIONS dip switch to adjust the Head
Pressure setpoint.
The Two Condenser Head Pressure II Module is directly
connected to the VCM-X Modular E-BUS, VCM-X WSHP
E-BUS or SA E-BUS Controller, allowing the Module(s) to
receive setpoints from the Controller.
When using the Two Condenser Head Pressure II Module with
the RNE Controller, refer to the
RNE Controller Technical Guide
.
The Two Condenser Head Pressure II Module also provides a
pulse width modulation (PWM) signal or voltage output signal
to control the condenser fans.
The Two Condenser Head Pressure II Module requires a 24 VAC
power connection with an appropriate VA rating.
Module Overview
Figure 1: Two Condenser Head Pressure II Module
Features
The Two Condenser Head Pressure II Module provides the
following:
• Can be operated stand alone or up to two modules can
be daisy-chained together and connected to a VCM-X
Modular E-BUS, VCM-X WSHP E-BUS, or SA E-BUS
Controller
• Monitors up to four individual head pressure transducers
• Provides control of Condenser Output Signals based on
the highest reading of head pressure transducers
• Capable of monitoring a Reverse Valve Signal
• Forces Condenser Fans to 100% while in the Heat Pump
Heating Mode
NOTE:
The Two Condenser Head Pressure II Module
contains no user-serviceable parts. Contact
qualified technical personnel if your Module is not
operating correctly.
NOTE:
The HSSC cable is no longer shipped with this
module. If it is to be used with a
VCM-X Modular
E-BUS, VCM-X WSHP E-BUS, or SA E-BUS
Controller, use the existing cable if possible.
ALARM
ANALOG
STAT
COMM
R1
R2
GND
RELAYS
R3
R4
Rc
AO1
AO2
PWM1-
PWM1+
PWM2-
PWM2+
ADDRESS
OPTIONS
+5V
SIG 2
GND
+5V
SIG 3
GND
+5V
SIG 4
GND
+5V
SIG 1
GND
BIN 1
BIN 2
BIN 3
COM
LABEL P/N:
G040380
E-BUS
SIG 1
GND
+5V
SIG 2
+5V
GND
+5V
SIG 3
GND
SIG 4
GND
+5V
+24
VAC
GND
BIN 1
BIN 2
BIN 3
COM
HEAD
PRESSURE
TRANSDUCER #1
HEAD
PRESSURE
TRANSDUCER #2
HEAD
PRESSURE
TRANSDUCER #3
HEAD
PRESSURE
TRANSDUCER #4
REV. VLV. ENABLE INPUT
PWM2+
ASM01891
AAON P/N:
AO2
GND
AO1
COND. A ENABLE INPUT
COND. B ENABLE INPUT
COND. A SIGNAL
COND. B SIGNAL
PWM1-
PWM1+
PWM2-
COND. FAN A
COND. FAN B
COND. FAN A
COND. FAN B
GND
HEAD PRESSURE II MODULE
HP2C2 TWO CONDENSER
www.aaon.com
RELA
Y CONT
ACT
RA
TING IS 1
AMP
MAX @ 24 V
AC
COND. A ENABLE
COND. B ENABLE
REV. VLV. A ENABLE
REV. VLV. B ENABLE
R1
R2
R3
R4
RC
RELAY COMMON
A1
A2
B1
B2
E-BUS
LED BLINK CODES
LED NAME
BLINKS QTY. OF SENSORS INSTALLED
LED NAME
STAT
ALARM
NO PROBLEMS
NO SENSORS DETECTED
HIGH HEAD PRESSURE
DETECTED
LOW HEAD PRESSURE
DETECTED
0
1
2
3
COMMON
