GarrettCom Magnum 3000 - Manual (Page 55)

Magnum 3000 Stackable Hubs Installation and User Guide (07/06)
48
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The –48VDC solution is particularly useful in the telecommunication industry,
where it is common for facilities to operate on -48VDC power. Such companies include
regular and wireless telephone service providers, Internet Service Providers (ISPs) and
other communication companies. In addition, many high availability equipment services,
such as broadcasters, publishers, newspaper operations, brokerage firms and other
facilities often use a battery backup system to maintain operations in the event of a power
failure. It is also frequently used for computer system backup, management and
operations monitoring equipment.
The 24VDC & 125VDC solution are particularly useful in the Industrial
environment, where it is common for facilities to operate on 24VDC or 125VDC power.
The 125VDC solution is mainly used in power utilities, such as electrical substations,
electrical generating plants, etc. The 24VDC applications are mainly in the Industrial
environment, such as factory floor, HVAC equipment, military equipment, etc.
B4.0 INSTALLATION
This section describes the
installation of the -48 VDC, 24VDC &
125VDC power source leads to the -48
VDC, 24VDC & 125VDC power terminal
block on the Magnum 3000 hubs. (see
figure at right).
Figure B4.1: -48VDC Terminal Block on Magnum 3000 hubs
In this picture, the -48VDC terminal block on the Magnum 3000s is located on
the rear of the unit and is equipped with three (3) screw-down lead posts. It is similar for
24VDC and 125VDC options on the Magnum 3000s. The leads are identified as
negative (-), positive (+), and chassis ground (GND).
The actual connection procedure is very straightforward. Simply connect the
leads to the Magnum unit, beginning with ground. Ensure that each lead is securely
tightened.
Note: The GND should be hooked up first. The 3000s 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 “+”.
An ON-OFF manual switch is optional for DC power . This can be used in to cut off
power connections and as a RESET for the Hub and / or SNMP Management Agent.
36-70VDC
_
+ GND
ON
OFF