GND
CHASSIS
GND
B-
B+
+
- FUSE
A-
HUB
SUPPLY
A+

Magnum Quad-Series Fiber Switches

Installation and User Guide (06/03)

All Port Module options are available for configuration with Dual-Source Option units. Refer to the main sections of this Installation and User Guide for a detailed description of the Magnum Quad-Series Switches.

C3.0 DUAL-SOURCE OPTION, THEORY OF OPERATION

The Dual-Source DC power option is designed using diodes inside of the switch 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 switch. This allows the switch 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 can receive power from either input, “A” or “B”. The switch will normally draw its power from the DC source with the highest voltage at a given time.

b)The switch 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 switch.

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, 24, 100 and 125VDC dual source leads to the DC power terminal block on the Magnum Quad-Series Switch (shown in Figure C4.0 with 48v input as example).

The –48VDC terminal block on the Magnum Quad-Series Switch is located on the right rear of the unit and is equipped with five (5) screw-down lead posts (see Figure 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. The dual source terminal block for 24, 100 and 125VDC are similar.

Figure on a Mag

A+ A- B- B+

36-70VDC 36-70VDC

GND

to the external Terminal Block

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GarrettCom Quad manual C3.0 DUAL-SOURCE OPTION, Theory of Operation, C4.0 Features and Benefits of the DUAL-SOURCE Design