CHAPTER B: DC POWER INPUT
ML810, 12, 24, –48, 125 AND 250VDC INSTALLATION
MULTILINK ML810 MANAGED EDGE SWITCH – INSTRUCTION MANUAL
B–5
B.4
ML810, 12, 24, –48, 125 and 250VDC Installation
This section describes the proper connection of the 12, 24, –48, leads to the DC power
terminal block on the Multilink ML810 Switch. The DC terminal block on the Multilink ML810
Managed Switch is located on the left front of the unit and is equipped with four (4) screw-
down lead posts. The power terminals are identified as positive (+) and negative (-), and
they are electrically floating inside the unit so that either may be grounded by the user if
desired. The chassis is “earth” or ground (GND).
The connection procedure is straightforward. Simply insert the DC leads to the Switch’s
power terminals, positive (+) and negative (-) screws. The use of Ground (GND) connects to
the Switch chassis screw provided under the DC terminal. Ensure that each lead is securely
tightened.
The connections for 125 and 250VDC are made by a fixed cord exiting the ML810 unit. (see
Fig. B4.0a for connection details).
Figure B-2: Connections for 125 and 250VDC power input
NOTE
Note
Always use a voltmeter to measure the voltage of the incoming power supply and figure
out the +ve potential lead or -ve potential lead. The more +ve potential lead will connect to
the post labeled “+ve” and the rest to the “-ve”. The GND can be hooked up at the last.
When power is applied, the green PWR LED will illuminate.
NOTE
Note
The GND should be hooked up first. The ML810 unit has a floating ground, so the user may
elect to Ground either + or - terminal to suit the customer’s use.
Before connecting live power lines to the Terminal Block of –48VDC, 12VDC, 24VDC, 125VD
or 250VDC products, 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 “+”.
B.4.1 UL Requirements for DC-powered units
CAUTION
48VDC products shall be installed with a readily accessible disconnect device in the
building installation supply circuit to the product.
1.
Minimum 18AWG cable for connection to a Centralized DC power source.
2.
Minimum 14AWG cable for connection to an earth wiring.
3.
Use only with Listed 10A circuit breaker provided in building installation.