Table Of Contents
Connecting to DC Power
Preparing for Installation
Grounding the Switch
Preparing the Ground Wire
Connecting the Grounding Wire to Earth Ground
Wiring the DC-Input Power Source
Cisco ME 3400-24TS Switches
Cisco ME 3400G-12CS Switches
All Cisco ME 3400 Switches
Connecting to DC Power
To connect the Cisco ME switch to a DC-input power source, follow these steps:
1. 
Preparing for Installation
2. Grounding the Switch
3. Wiring the DC-Input Power Source
Warning Before performing any of the following procedures, ensure that power is removed from the DC circuit. Statement 1003
Warning This unit is intended for installation in restricted access areas. A restricted access area can be accessed only through the use of a special tool, lock and key, or other means of security. Statement 1017
Caution Installation of the equipment must comply with local and national electrical codes.
Note We recommend that you use 18 AWG copper wiring for Network Equipment Building Systems (NEBS) installation. This guideline follows the standard guidelines for DC power wiring in the Central Office.
Note You can use the grounding lug to attach a wrist strap for ESD protection during servicing.
Preparing for Installation
Locate the DC terminal block plug, the ground lug, and the two number-10-32 screws in the DC-switch kit.
Obtain these necessary tools and equipment:
•Ratcheting torque screwdriver with a Phillips head that exerts up to 15 pound-force inches (lbf-in.) of pressure
•Panduit crimping tool with optional controlled cycle mechanism (model CT-700, CT-720, CT-920, CT-920CH, CT-930, or CT-940CH)
•6-gauge copper ground wire (insulated or noninsulated)
•Four leads of copper wire
•The DC terminal block (Figure C-13)
•12-28 AWG copper wire
•Wire-stripping tools
To order spare or replacement DC connectors, use one of these sources:
•Digi-Key, part number 277-1013-ND, www.digikey.com
•Phoenix Contact, part number 1757035, www.phoenixcontact.com
Grounding the Switch
Review these safety warnings before you ground the switch.
Warning This equipment must be grounded. Never defeat the ground conductor or operate the equipment in the absence of a suitably installed ground conductor. Contact the appropriate electrical inspection authority or an electrician if you are uncertain that suitable grounding is available. Statement 1024
Warning When installing or replacing the unit, the ground connection must always be made first and disconnected last. Statement 1046
Caution To make sure that the equipment is reliably connected to earth ground, follow the grounding procedure instructions, and use a UL-listed lug suitable for number-6 AWG wire and two number-10-32 ground-lug screws.
Preparing the Ground Wire
Before you ground the switch to earth ground, you must prepare the ground wire. Follow these steps. Make sure to follow any grounding requirements at your site.
Step 1 Locate the ground lug and the two number-10-32 screws. A ground lug and screws are located both on the front panel and on the rear panel of the switch. Only one ground connection is required.
Use a standard Phillips screwdriver or a ratcheting torque screwdriver with a Phillips head. Set the screws and the ground lug aside.
Step 2 If your ground wire is insulated, use a wire stripping tool to strip the 6-gauge ground wire to 0.5 inch (12.7 millimeter [mm]) ± 0.02 inch (0.5 mm) as shown in Figure C-1.
Figure C-1 Stripping the Ground Wire
Step 3 Slide the open end of the ground lug over the exposed area of the 6-gauge wire.
Step 4 Using a Panduit crimping tool, crimp the ground lug to the 6-gauge wire.
Figure C-2 Crimping the Ground Lug
Step 5 Use the two number-10-32 screws to attach the ground lug and wire assembly to the rear panel of the switch.
Step 6 Using a ratcheting torque screwdriver, torque each ground-lug screw to 15 lbf-in. (240 ounce-force inches [ozf-in.]). Figure C-3 shows how to torque the ground screws on a Cisco ME DC switch.
Figure C-3 Torquing Ground-Lug Screws
Connecting the Grounding Wire to Earth Ground
Next you must connect the other end of the grounding wire to an appropriate grounding point at your site or to the telco rack. You can connect the grounding wire to either the front panel ground connector (see Figure C-4) or the rear panel ground connector (see Figure C-5), but not to both.
Figure C-4 Connecting the Grounding Wire to the Rack from the Front-Panel Ground Connector
1
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Telco rack
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2
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Grounding wire
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Figure C-5 Connecting the Grounding Wire to the Rack from the Rear-Panel Ground Connector
1
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Telco rack
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2
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Grounding wire
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Complete these steps:
Step 1 Remove all paint or oxidation from the rack at the point of the grounding connection.
Step 2 Use a 3/16-inch flat-head screwdriver to loosen the grounding screw on the rack.
Step 3 Connect the wire to a ring lug (large enough for the rack screw to fit through).
Step 4 Use a 3/16-inch flat-head screwdriver and the screw to attach the ring lug to the rack.
Step 5 Tighten the grounding screw on the rack over the ring lug.
Repeat these steps for each switch being installed.
Wiring the DC-Input Power Source
Before you wire the DC-input power source, review the warnings in this section and this information:
If the switch software detects that the circuit boards are not receiving power from an internal power supply, the software sends a message like this to the console:
00:06:54: %POWER_SUPPLIES-3-PWR_FAIL: Power supply 2 is not functioning
00:06:54: %PLATFORM_ENV-1-DUAL_PWR: Faulty internal power supply 2 detected
This message means that an internal power supply is not providing power. To receive this alert if power fails on the ME 3400G-12CS-DC switch with two power feeds, we recommend that you connect one feed to the left DC power terminal block and the other to the right DC power terminal block. (See the example in Figure C-6.)
Figure C-6 Connecting Separate Feeds to Each of the DC Power Terminal Blocks
1
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Primary power feed
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2
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Secondary (redundant) power feed
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If you want to receive an alert if an external power supply fails, do not connect feeds to one terminal block and from there connect feeds to the second terminal block. (See the example in Figure C-7.) This configuration provides redundant power, and the switch continues to operate if one of the external power supplies fails. However, the software does not send a message to you that an internal power supply has failed.
Figure C-7 Connecting Feeds from One Terminal Block to the Second Terminal Block
Cisco ME 3400-24TS Switches
This warning only applies to Cisco ME 3400-24TS switches:
Warning This product relies on the building's installation for short-circuit (overcurrent) protection. Ensure that the protective device is rated not greater than:
5 A Statement 1005
Cisco ME 3400G-12CS Switches
This warning only applies to Cisco ME 3400G-12CS switches:
Warning This product relies on the building's installation for short-circuit (overcurrent) protection. Ensure that the protective device is rated not greater than:
6 A Statement 1005
All Cisco ME 3400 Switches
These warnings apply to all Cisco ME switches:
Warning A readily accessible two-poled disconnect device must be incorporated in the fixed wiring.
Statement 1022
Warning Only trained and qualified personnel should be allowed to install or replace this equipment.
Statement 1030
Caution You must connect the Cisco ME DC switch only to a DC-input power source with -36 to -72 VDC supply voltage. If the supply voltage is not in this range, the switch might not operate properly or might be damaged.
Caution The Cisco ME 3400G-12CS-DC switch has two DC power supplies. They are labelled PS1 and PS2, and each power supply has an A and B input. When you connect power to both PS 1 and PS 2, connect only a single input (A or B) to each power supply.
To wire the switch to a DC-input power source, follow these steps:
Step 1 To ensure that all power is OFF, locate the circuit breaker on the panel board that services the DC circuit, switch the circuit breaker to the OFF position, and tape the switch handle of the circuit breaker in the OFF position.
Step 2 Locate the terminal block plug (see Figure C-8).
Figure C-8 Terminal Block Plug
Step 3 Identify the positive and negative feed positions for the terminal block connection. The wiring sequence is positive to positive and negative to negative for both the A and the B feed wires.
The front panel of the switch shows the positive and negative positions for both the A and B feed wires (See Figure C-9, which shows a Cisco ME 3400-24TS-DC switch.)
Figure C-9 Positive and Negative Positions
Step 4 Using an 18-gauge wire-stripping tool, strip each of the four wires coming from the DC-input power source to 0.27 inch (6.6 mm) ± 0.02 inch (0.5 mm). Do not strip more than 0.29 inch (7.4 mm) of insulation from the wire. Stripping more than the recommended amount of wire can leave exposed wire from the terminal block plug after installation.
Figure C-10 Stripping the DC-Input Power Source Wire
Step 5 Insert the exposed wire of one of the four DC-input power source wires into the terminal block plug, as shown in Figure C-11. Make sure that you cannot see any wire lead. Only wire with insulation should extend from the terminal block.
Warning A readily accessible two-poled disconnect device must be incorporated in the fixed wiring.
Statement 1022
Figure C-11 Inserting Wires in the Terminal Block Plug
1
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Return (positive) Feed A
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3
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Return (positive) Feed B
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2
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Supply (negative) Feed A
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4
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Supply (negative) Feed B
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Step 6 Use a ratcheting torque screwdriver to torque the terminal block captive screw (above the installed wire lead) to 4.5 lbf-in. (72 ozf-in.). (See Figure C-12.)
Caution Do not overtorque the terminal-block captive screws. The recommended maximum torque is 4.5 lbf-in.
Figure C-12 Torquing the Terminal-Block Captive Screws
Step 7 Repeat Steps 4 and 5 for the remaining three DC-input power source wires. Figure C-13 shows the completed wiring of a terminal block plug.
Figure C-13 Completed Wiring of Terminal Block Plug
1
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Return (positive) Feed A
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3
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Return (positive) Feed B
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2
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Supply (negative) Feed A
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4
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Supply (negative) Feed B
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Step 8 Insert the terminal block plug in the terminal block header on the front panel of the switch. (See Figure C-14).
Caution Secure the wires coming in from the terminal block so that they cannot be disturbed by casual contact. For example, use tie wraps to secure the wires to the rack.
Figure C-14 Inserting the Terminal Block in the Block Header
Step 9 Remove the tape from the circuit-breaker switch handle, and move the circuit-breaker handle to the on position.
