Installation Guide

Operation
900-0009-01-00 Rev C 27
Aux Screens
The AUX (Auxiliary) is a secondary control circuit — essentially, a small power supply that provides a
12 Vdc output current (up to 200 milliamps/2.4 watts) to an isolated load. It is either ON (Active High)
with 12 Vdc available at the output or OFF (Active Low) with 0 Vdc at the output. It can also be set to
AUTO, so that it activates when certain criteria are met.
The AUX output can respond to specific criteria and control cooling fans, vent fans, load diversion,
fault alarms, and automatic generator control. In some cases, such as the PV Trigger, Night Light, or
Diversion:Relay applications, the polarity of the output can be reversed so that a lack of power
activates the output. This function is controlled through the Aux Polarity screen in the ADVANCED
MENU. (See page 53.)
NOTE: Diversion:Relay and Diversion:Solid St can be used for AC coupling applications.
The AUX output can also be controlled externally through the system display. See the Owner's Manual
for the system display (if used) for details.

Only one
AUX MODE
can operate at a time (even if other modes have been preset).

See Figure 27, page 39, for an auxiliary setup wiring diagram example.
Table 2 Aux Mode Functions
Mode Name Function/Purpose Set Points Aux Polarity
Vent Fan
Function:
When the threshold voltage set point is
exceeded, the AUX output will change state for
at least 15 seconds. If the set point continues to
be exceeded, the output will remain in that state
until the voltage falls below the set point.
Once the voltage decreases below the threshold
voltage, the AUX output will remain in that state
for another 15 seconds. It will then deactivate.
Purpose:
This mode is intended to operate a vent fan for a
battery enclosure to ventilate hydrogen gas
from the enclosure.
 Threshold
Voltage
Not Available
PV Trigger
Function:
When the threshold voltage set point is
exceeded, the AUX output will activate.
When the threshold voltage decreases below
the voltage set point, the output will remain
active for the duration of the hold time set by
the user.
Purpose:
This mode is intended to operate an alarm, or
relay that disconnects the PV array, when
PV input exceeds the threshold voltage set by
the user. The mode deactivates the alarm or
PV disconnect after the time set point has
been
reached.
NOTE: Do not exceed 150 Vdc or the FLEXmax
could be damaged.
 Threshold
Voltage
 Hold Time
Active High: Activates the
output when the voltage
exceeds the set point.
Active Low: Deactivates the
output when the voltage
exceeds the set point.