Orion System PREHEAT-X - Manual (Page 8)

INPUTS & OUTPUTS
PREHEAT-X Technical Guide 8
Inputs and Outputs
Table 1: PREHEAT-X Controller Inputs & Outputs
Analog Inputs
Leaving Air Temperature 1 (LAT1)
When enabled, the PREHEAT-X Controller will control to a Leav-
ing Air Temperature Setpoint. The Controller can be confi gured to
use only LAT 1 for this purpose. Typically, the average of LAT1
and LAT2 is used.
Leaving Air Temperature 2 (LAT2)
When enabled, the PREHEAT-X Controller will control to a Leav-
ing Air Temperature Setpoint. The Controller can be confi gured to
use only LAT 2 for this purpose. Typically, the average of LAT1
and LAT2 is used.
Entering Air Temperature
When the Entering Air Temperature falls below the Entering Air
Temperature Setpoint, preheat will be enabled.
I/O Map
See Table 1 below to reference the inputs and outputs that are avail-
able on the PREHEAT-X Controller.
Analog Inputs
1 Leaving Air Temperature 1 (LAT1)
2 Leaving Air Temperature 2 (LAT2)
3 Entering Air Temperature Sensor
4 Reset In (0-10 VDC)
Binary Inputs
1 Heat Enable
2 Emergency Shutdown
3 Future Use
Analog Outputs
1 0-10 VDC Mod SCR
2 PWM SSR
Relays
1 Alarm
2 Heat 1
3 Heat 2
4 Heat 3
5 Heat 4
6 Heat 5
7 Heat 6
NOTE: For AIN1 through AIN3, all Temperature Sensors must
be Thermistor Type III which provide 77.0°F @ 10K
Ohms Resistance.
Reset Input (0-10 VDC)
Used only in stand-alone operation. The Leaving Air Temperature
Setpoint can be reset by supplying a 0-10 VDC signal to the RST
IN low voltage terminal block. This reset signal is optional and need
only be used if you require resetting of the discharge air temperature.
Binary Inputs
Heat Enable Contact (HEAT EN)
This input is only required when the controller is used in stand-alone
operation; it is not required when communicating with an AAON
Unit Controller. The Heat Enable input is activated by a 24VAC
signal supplied from a building automation system to enable the
PREHEAT-X Controller. The controller will not operate without
24VAC being applied to this input terminal when used in a stand-
alone confi guration. When the Heat Enable signal is lost or turned
off, all stages de-activate immediately.
Emergency Shutdown Input
This wet contact (24 VAC) input is used to initiate shutdown of the
HVAC unit when a N.C. Smoke Detector (by others), Firestat (by oth-
ers), or other shutdown condition (by others) occurs and the contact
is opened. The controller remains active and can initiate alarm relays.
Analog Outputs
0-10 VDC Modulating SCR
Depending on the type of Heat used, this output will supply a 0-10
VDC output signal for control of the modulating SCR Heat.
Pulse Width Modulating SSR
Depending on the type of Heat used, this output will supply a 12 V
PWM Output Signal for control of the modulating SSR Heat.
Relay Outputs
Relay #1 - Alarm
This relay sends a signal when an alarm is enabled.
Relays #2 - 6—Fixed Stage Heat Outputs