Zone
Zone
SECTION 4: TROUBLESHOOTING
Main Chiller Controller Technical Guide
40
Contr
ol
De
vice
V
olta
ge
V
A Load
Oper
ating
Temper
atur
e
Humidity
(Non-
Condensing)
Chiller
Expansion
Module
24VAC
(25%/-15%),
Class 2
5
-30°F to
150°F
0-95% RH
Inputs
Resistive Inputs require
10K
Ω
Type 3 Thermistor
24VAC Inputs provide
4.7
kΩ
Load
Outputs
Relay Outputs: 1 Amp
maximum per output.
Table 9: Chiller Expansion Module Electrical and
Environmental Requirements
Contr
ol
De
vice
V
olta
ge
V
A Load
Oper
ating
Temper
atur
e
Humidity
(Non-
Condensing)
Compressor
Circuit
Module
&
Economizer
Subcool
Module
24VAC
(25%/-15%),
Class 2
18
-30°F to
150°F
0-95% RH
Inputs
Resistive Inputs require
10K
Ω
Type 3 Thermistor
24VAC Inputs provide
4.7
kΩ
Load
Outputs
Relay Outputs: 1 Amp
maximum per output.
Table 10: Compressor Circuit Module & Economizer
Subcool Module Electrical and Environmental
Requirements
Important Wiring Considerations
General
Correct wiring of the Main Chiller Controller and its modules is
the most important factor in the overall success of the controller
installation process. The Main Chiller Controllers and Modules
are factory installed and wired at the AAON
®
factory. Some of the
following information may not apply to your installation if it was
pre-wired at the factory. However, if troubleshooting of the controller
is required, it is a good idea to be familiar with the system wiring.
Wiring
The Main Chiller Controller and associated modules must be
connected to an 18-30 VAC power source of the proper size for the
calculated VA load requirements. All transformer sizing should be
based on the VA rating listed in
Tables 8, 9 & 10
.
Table 8: Main Chiller Controller Electrical and
Environmental Requirements
Contr
ol
De
vice
V
olta
ge
V
A Load
Oper
ating
Temper
atur
e
Humidity
(Non-
Condensing)
Main
Chiller
Controller
24VAC
(25%/-15%),
Class 2
15
-30°F to
150°F
0-95% RH
Inputs
Resistive Inputs require
10
KΩ
Type 3 Thermistor
24VAC Inputs provide
4.7
kΩ
Load
Outputs
Relay Outputs: 1 Amp
maximum per output.