4 Power Supply 
The SCADAPack LP is powered from an 11VDC to 24VDC input power source.  
•  Input power is applied to the 11-24Vdc positive (+) and negative (-) terminals on connector P3. 
Refer to section 14-Specifications of this manual for the minimum and maximum operating voltages 
and input power requirements.  
•  When the input voltage is below the minimum recommended voltage the SCADAPack LP will 
turn off.   
•  Exceeding the maximum input voltage or applying a reverse voltage will blow the input power 
fuse. 
Note:  Unlike the other members of the SCADAPack family, the SCADAPack LP connects only to 
DC power sources. Connections to power sources such as 16Vac transformers will blow the 
fuse and may cause damage to the SCADAPack LP. 
The DC power-input voltage is used to generate 5V for the SCADAPack LP circuitry. The output 
capacity of the 5V supply is sufficient to power the SCADAPack LP and a SCADAPack Vision 
operator interface with 100mA remaining capacity for a limited number of 5000 Series I/O modules.  
For 12VDC power-input voltages a 12V to 24V DC/DC converter is used to power 20mA analog 
input and output devices. The DC/DC converter is controlled by the user application program and 
may turned on or off. Refer to section 4.2.3-12V to 24V DC/DC Converter Control for more 
information on DC/DC converter control. 
4.1 System Grounding 
In most applications, it is desirable to ground the system by connecting the system power supply 
common, to the chassis or panel ground. The negative (–ve) side of the DC power input terminal as 
well as all I/O point terminals labeled GND are connected to chassis ground. 
4.2  Power Management Features 
The SCADAPack LP provides a number of special features to reduce power consumption. These 
power management features are: 
•  COM3 serial port power control. 
•  VLoop power control. 
•  12V to 24V DC/DC Converter Control. 
The SCADAPack LP provides three internal digital outputs that can be operated by the user 
application to manage the power saving features. Internal digital outputs 9, 10 and 11 and the power 
management functions they control are described in the following sections.  
Refer to Figure 3:  Power Management for an overview of the power management features. Refer 
to the appropriate software manual for information on using and controlling the internal Digital 
Outputs. For TelePACE applications refer to the Register Assignment for SCADAPack LP I/O 
module and for ISaGRAF applications refer to the I/O Complex Equipment for SCADAPack LP I/O. 
SCADAPack LP Hardware Manual 
May 26, 2006   
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