GarrettCom 6K25 manual C4.0 Features and Benefits of the DUAL-SOURCE Design, C5.0 Installation

Magnum 6K25 Managed Fiber Switch Installation and User Guide (04/06)

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 and 125VDC dual source leads to the -48VDC, 24VDC 7 125VDC power terminal block on the Magnum 6Ks Switch (shown in Figure )

The -48VDC terminal block on the Magnum 6K25 Switch, as shown in Fig C5.0 is

located on the right rear of the unit and
is equipped with five (5) screw-down	A+ A-	B- B+
lead posts. If it is the reverse model it
is located on the left rear. The primary
terminals are identified as positive
(A+), negative (A-), and the secondary		36-70VDC
power terminals as negative (B-),	36-70VDC		GND

positive(B+). The chassis “earth” or ground (GND) is a threaded post with a #6 nut. The Dual Source terminal block for the 24VDC and 125VDC are similar.

Figure C5.0: -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 6K25 unit has a floating ground, so the user may elect to Ground either + or = terminal to suit the customer’s use.

Before connecting hot lines to the Terminal Block of –48VDC, 24VDC or 125VDC, always use a digital voltmeter to measure the output voltage of the power supply and determine the lead which is more “+ve potential”. The more “+ve” voltage lead from 48V or –48V supply must be connected to the post labeled “+”.

The connection procedure is straightforward. Simply connect the DC leads to the Switch’s power terminals, positive (+) and negative (-) screws. The use of Ground (GND) is optional; it connects to the Switch chassis. Ensure that each lead is securely tightened.

The 24VDC & 125VDC terminal block on Magnum 6K25’s is similar to that described in the –48VDC information above.

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