GarrettCom 4K16 Manual Do Utilizador

Magnum 4K16 Switches    Installation and User Guide       

(12/05) 

 

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Source power supply are designed for installations where a battery plant is the power 
source, and where two separate power sources are utilized in order to increase 
operational uptime and to simplify maintenance.  

The functionality of the Magnum 4K-Series -48VDC, 24VDC & 125VDC 

Dual-Source Option units are identical to the standard AC-powered models.  Refer to the 
main sections of this Installation and User Guide for a detailed description of the 
Magnum 4K-Series Switches. 

 

The Dual-Source DC power option is designed using diodes inside of the 

chassis on each DC power input line. A diode is placed in each of the four input lines 
(behind the four external power connection 
terminals) so that power from an external 
source can only flow into the unit.  This 
allows the unit to operate whenever DC 
power is correctly applied to either or both 
of the two inputs 
 
 
C4.0 

FEATURES AND BENEFITS OF THE DUAL-SOURCE DESIGN 

a) 

The Switch unit can receive power from either input, “A” or “B”.  The hub will normally draw 

its power from the DC source with the highest voltage  at a given time. 

b) 

The Switch unit will not allow power to flow from a higher voltage input to a lower voltage 

input, i.e. the two DC power sources are not mixed together by the hub. 

c) 

When one correct DC input is present, the Switch will receive power if the other DC input is 

absent, or even if it is connected with reverse polarity or shorted or grounded. 

d) 

Reverse polarity connections, if they should accidentally occur on either input, will not damage 

the Switch or power supply internally (nor will it blow the fuse in the internal power supply) 
because of the blocking action of the diodes.  This is true even if one input connection is 
reversed while the Switch is operating from the other source. 

e) 

The Switch will not receive power (and will not work) when both inputs are simultaneously 

absent or are both incorrectly connected.

  

 
C5.0 INSTALLATION 

 

This section describes the proper connection of the -48VDC, 24VDC & 

125VDC dual source leads to the -48VDC, 24VDC and 125VDC power terminal block 
on the Magnum 4K-Series Switch (shown in Figure ) 
 

The -48VDC terminal block on the Magnum 4K-Series Switch is located on 

the right rear of the unit and is equipped 
with five (5) screw-down lead posts (see 
Fig C5.0).  The primary terminals are 
identified as positive (A+), negative (A-
), and the secondary power terminals as 
negative (B-), positive(B+).  The 
chassis “earth” or  ground (GND), is a 
threaded post with a #6 nut.   
 

 FigureC5.0:  -48VDC Dual-Source, wiring connections to the External 

Terminal Block on a Magnum 48VDC with Dual-Source option   
 
Note: The GND should be hooked up first.  The 4K unit has a floating ground, so the 
user may elect to Ground either + or  = terminal to suit the customer’s use. 

GND

FUSE

+

-

SUPPLY

A+

A-

B-

B+

GND

CHASSIS

HUB