Emerson ROC827 - Manual (Page 50)

ROC827 Instruction Manual
Issued Mar-06 Power Connections 3-6
3.1.4 Switched Auxiliary Output (AUXSW+ and AUXSW–)
The AUX
SW
+ and AUX
SW
– terminals on the 12 volt dc Power Input
module (PM-12) provide switched power for external devices, such as
radios. AUX
SW
+ is current-limited for protection of the power input and
the external device via a 0.5 Amp nominal Positive Temperature
Coefficient (PTC). The AUX
SW
+ and AUX
SW
– terminals provide
voltages from 0 to 14.25 Volts dc. AUX
SW
+ is turned off when the
ROC827 detects a software configurable voltage (LoLo Alarm) at the
BAT+ and BAT– terminals. All module terminal blocks accept 12 AWG
or smaller wiring. Refer to Figure 3-3.
If the source voltage falls to a level below which reliable operation cannot
be ensured, the hardware circuitry on the Power Input module
automatically disables the AUX
SW
+ outputs. This activity occurs at
approximately 8.85 Volts dc, and is based on the LoLo Alarm limit set for
the System Battery Analog Input Point Number 1. The low input voltage
detect circuit includes approximately 0.75 Volts dc of hysteresis between
turn-off and turn-on levels.
The presence of high input voltage can damage the linear regulator. If the
dc input voltage at BAT+ exceeds 16 volts, the over-voltage detect circuit
automatically disables the linear regulator, shutting off the unit. For
further information on the STATUS LED functions, refer to Table 2-2 in
Chapter 2, Installation and Use.