Connecting the EX8200 to Power
Connect Earth Ground to an EX Series Switch
To ensure proper operation and to meet safety and electromagnetic interference (EMI) requirements, you must connect an EX Series switch to earth ground before you connect power to the switch. You must use the protective earthing terminal on the switch chassis to connect the switch to earth ground (see Figure 2).
You must install the EX Series switch in a restricted–access location and ensure that the chassis is always properly grounded. EX Series switches have a two–hole protective grounding terminal provided on the chassis. See Table 1 for the location of the earthing terminals on various EX Series switches. We recommend that you use the protective grounding terminal as the preferred method for grounding the chassis regardless of the power supply configuration. However, if additional grounding methods are available, you can also use those methods. For example, you can use the grounding wire in the power cord of an AC power supply or use the grounding terminal or lug on a DC power supply. This system was tested to meet or exceed all applicable EMC regulatory requirements with the two-hole protective grounding terminal connected correctly.
Ensure that a licensed electrician has attached an appropriate grounding lug to the grounding cable you supply. Using a grounding cable with an incorrectly attached lug can damage the switch.
Parts and Tools Required for Connecting an EX Series Switch to Earth Ground
Special Instructions to Follow Before Connecting Earth Ground to an EX Series Switch
Parts and Tools Required for Connecting an EX Series Switch to Earth Ground
Before you begin connecting an EX Series switch to earth ground, ensure you have the parts and tools required for your switch.
Table 1 lists the earthing terminal location, grounding cable and lug specifications, and parts needed for connecting an EX Series switch to earth ground.
Table 1: Parts Required for Connecting an EX Series Switch to Earth Ground
Switch | Earthing Terminal Location | Grounding Cable Requirements | Grounding Lug Specifications | Screws and Washers | Additional Information |
---|---|---|---|---|---|
EX2200 | Rear panel of the chassis | 14 AWG (2 mm²), minimum 90° C wire, or as permitted by the local code | Panduit LCC10-14BWL or equivalent— |
| |
EX2300-C | Rear panel of the chassis | 14 AWG (2 mm²), minimum 90° C wire, or as permitted by the local code | Panduit LCC10-14AW-L or equivalent— |
| |
EX2300 | Rear panel of the chassis |
|
|
| |
EX3200, EX3300, and EX3400 | Rear panel of the chassis | 14 AWG (2 mm²), minimum 90° C wire, or as permitted by the local code | Panduit LCC10-14BWL or equivalent— |
| For EX3200 Switches See Special Instructions to Follow Before Connecting Earth Ground to an EX Series Switch. |
EX4200, EX4500, and EX4550 | Left side of the chassis | 14 AWG (2 mm²), minimum 90° C wire, or as permitted by the local code | Panduit LCC10-14BWL or equivalent— |
| See Special Instructions to Follow Before Connecting Earth Ground to an EX Series Switch. |
EX6210 | Rear panel of the chassis (on lower left side) | The grounding cable must be the same gauge as the power feed cables and as permitted by the local code. | Panduit LCD2-14A-Q or equivalent |
| |
EX8208 | Left side of the chassis | 6 AWG (13.3 mm²), minimum 90° C wire, or as permitted by the local code | Panduit LCD2-14A-Q or equivalent |
| |
EX8216 | Two earthing terminals:
Note: You must use only one of the two protective earthing terminals. | 2 AWG (33.6 mm²), minimum 90° C wire, or as permitted by the local code | Panduit LCD2-14A-Q or equivalent |
| |
EX9204, EX9208, and EX9214 | Rear panel of the chassis | One 6 AWG (13.3 mm²), minimum 90° C wire, or one that complies with the local code | Thomas& Betts LCN6-14 or equivalent— |
| See Grounding Cable and Lug Specifications for EX9200 Switches. |
EX9251 | Rear panel of the chassis | 12 AWG (2.5 mm²), minimum 90° C wire,
or one that complies with the local code— | Panduit LCD10-10A-L or equivalent— | Two 10-32 screws— | See Grounding Cable and Lug Specifications for EX9200 Switches. |
EX9253 | Right side of the chassis | 14-10 AWG (2-5.3 mm²), minimum 90° C wire,
or one that complies with the local code— | Panduit LCD10-14B-L or equivalent— | Two M5 Pan Head screws— |
Tools required for connecting an EX Series switch to earth ground:
An electrostatic discharge grounding strap (provided)
A Phillips (+) number 2 screwdriver to tighten the screws.
An AC–powered EX Series switch gains additional grounding when you plug the power supply in the switch into a grounded AC power outlet by using an AC power cord appropriate for your geographical location.
Special Instructions to Follow Before Connecting Earth Ground to an EX Series Switch
Table 2 lists the special instructions that you might need to follow before connecting earth ground to a switch.
Table 2: Special Instructions to Follow Before Connecting Earth Ground to an EX Series Switch
Switch | Special Instructions | ||||
---|---|---|---|---|---|
EX3200 and EX4200 | Some early variants of EX3200 and EX4200 switches for which the Juniper Networks model number on the label next to the protective earthing terminal is from 750-021xxx through 750-030xxx require 10-24x.25 in. screws. | ||||
EX4200, EX4500, and EX4550 | If you plan to mount your switch on four posts of a rack or cabinet, mount your switch in the rack or cabinet before attaching the grounding lug to the switch. Note: The protective earthing terminal on switches mounted on four posts of a rack is accessible through the slot on the left rear bracket only if the rack is 27.5 in. (69.85 cm) through 30.5 in. (77.47 cm) deep for a switch mounted flush with the rack front and 29.5 in. (74.93 cm) through 32.5 in. (82.55 cm) deep for a switch mounted 2 in. (5.08 cm) recessed from the rack front. See Figure 1. ![]()
Note: The brackets must be attached to the chassis before the grounding lug is attached. (The brackets are shown pulled away from the chassis so that the protective earthing terminal is seen.) |
Connecting Earth Ground to an EX Series Switch
To connect earth ground to an EX Series switch:
- Verify that a licensed electrician has attached the cable lug to the grounding cable.
- Connect one end of the grounding cable to a proper earth ground, such as the rack in which the switch is mounted.
- Attach an ESD grounding strap to your bare wrist, and connect the strap to the ESD grounding point on the switch.
- Place the grounding lug attached to the grounding cable
over the protective earthing terminal. See Figure 2.
Figure 2: Connecting a Grounding Cable to an EX Series Switch - Secure the grounding lug to the protective earthing terminal with the washers and screws.
- Dress the grounding cable and ensure that it does not touch or block access to other switch components and that it does not drape where people could trip over it.
Connecting AC Power to an EX8200 Switch
EX8200 switches can be configured with up to six AC power supplies. After you have installed at least one power supply, you can connect power to the switch.
Mixing different types of power supplies in the same chassis is not a supported configuration.
Each power supply must be connected to a dedicated AC power source outlet.
Before you begin to connect power to the switch:
Ensure you understand how to prevent ESD damage. See Prevention of Electrostatic Discharge Damage.
Ensure that you have connected the device chassis to earth ground, if required by your site guidelines or installation. A ground connection to the protective earthing terminal is not required for an AC-powered switch. The AC power cords provide adequate grounding when you connect the power supply in the switch to a grounded AC power outlet by using the AC power cord appropriate for your geographical location (see AC Power Cord Specifications for an EX8200 Switch).
Caution For installations that require a separate grounding conductor to the chassis, have a licensed electrician complete this connection before you connect the switch to power. For instructions on connecting earth ground, see Connect Earth Ground to an EX Series Switch.
Install power supplies in the switch. See Installing an AC Power Supply in an EX8200 Switch.
Ensure that you have the following parts and tools available to connect power to the switch:
Electrostatic discharge (ESD) grounding strap
Power cords appropriate for your geographical location. See AC Power Cord Specifications for an EX8200 Switch.
Ensure that the power cords do not block access to switch components or drape where people can trip on them.
To connect AC power to an EX8200 switch:
- Attach the electrostatic discharge (ESD) grounding strap to your bare wrist, and connect the strap to the ESD point on the chassis.
- Ensure that the power supply is fully inserted and latched securely in the chassis. SeeInstalling an AC Power Supply in an EX8200 Switch.
- Flip the Enable switch, which is next to the appliance inlet on the power supply faceplate, to the Standby position.
- Squeeze the two sides of the power cord retainer clip,
and insert the L-shaped ends of the clip into the holes in the bracket
on each side of the AC appliance inlet on the AC power supply faceplate.
See Figure 3.
Figure 3: Power Cord Retainer in an AC Power Supply - Locate the power cord or cords shipped with the switch; the cords have plugs appropriate for your geographical location.
- Insert the coupler end of the power cord into the AC appliance
inlet on the AC power supply faceplate.
Note If the power cord tray is installed, you can thread the power cord through the power cord tray. See Figure 4.
- Push the cord (close to the coupler end) into the slot in the adjustment nut of the power cord retainer. Rotate the nut until it is tight against the base of the coupler and the slot in the nut is turned 90° from the top of the switch. See Figure 4.
- If the AC power source outlet has a power switch, set it to the OFF (0) position.
- Insert the power cord plug into an AC power source outlet.
- If the AC power source outlet has a power switch, set it to the ON (|) position.
- Verify that the INPUT OK LED on the power supply faceplate is lit and is on steadily.
- Repeat steps 2 through 11 for the remaining power supplies.

See also
Connecting DC Power to an EX8200 Switch
An EX8200 switch can be configured with up to six DC power supplies. After you have installed at least one power supply, you can connect power to the switch.
Before performing DC power procedures, ensure that power is removed from the DC circuit. 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.
EX8208 switches support 2000 W DC power supplies.
EX8216 switches support 3000 W DC power supplies.
Before you connect power to the switch, a licensed electrician must attach a cable lug to the grounding and power cables that you supply. A cable with an incorrectly attached lug can damage the switch (for example, by causing a short circuit).
Do not mix different types of power supplies in the same chassis.
Before you begin connecting DC power to an EX8200 switch:
Ensure that you have taken the necessary precautions to prevent ESD damage (see Prevention of Electrostatic Discharge Damage).
Ensure that you have connected the switch chassis to earth ground.
Caution To meet safety and electromagnetic interference (EMI) requirements and to ensure proper operation, you must connect EX8200 switches to earth ground before you connect them to power. For installations that require a separate grounding conductor to the chassis, use the protective earthing terminal on the switch chassis to connect to earth ground. For instructions on connecting an EX8200 switch to ground using a separate grounding conductor, see Connect Earth Ground to an EX Series Switch.
Install the power supply in the chassis. See Installing a DC Power Supply in an EX8200 Switch.
Ensure that you have the following parts and tools available to connect DC power to an EX8200 switch:
Electrostatic discharge (ESD) grounding strap
DC power source cables (not provided) with the cable lugs (provided) attached.
The provided cable lugs in an EX8208 switch are sized for 6 AWG (13.3 mm2) power source cables. The DC power source cables that you provide must be 6 AWG (13.3 mm2), minimum 60°C wire. We recommend that you install heat-shrink tubing insulation around the power cables and lugs.
The provided cable lugs in an EX8216 switch are sized for 2 AWG (33.6 mm2) power source cables. The DC power source cables that you provide must be 2 AWG (33.6 mm2), minimum 60°C wire. We recommend that you install heat-shrink tubing insulation around the power cables and lugs.
3/8 in. (9.5 mm) nut driver or socket wrench
Phillips (+) screwdriver, number 2
Multimeter
To connect DC power to an EX8200 switch:
- Attach the electrostatic discharge (ESD) grounding strap to your bare wrist, and connect the strap to the ESD point on the chassis.
- Flip the
Enable
switch on the power supply faceplate to the Standby position.Note It might be necessary to slide each power supply partially out of the chassis, in order to easily connect the DC power source cables to the DC power input terminals. See Removing a DC Power Supply from an EX8200 Switch.
- Remove the plastic cable cover from the DC power input
terminals, using the number 2 Phillips (+) screwdriver
to loosen the screw (see Figure 5).
Figure 5: Removing the Plastic Cable Cover on a DC Power Supply in an EX8200 Switch - Remove the washers and nuts from each DC power input terminal, using the 3/8-in. (9.5 mm) nut driver or socket wrench to loosen the nuts. Leave the bolts installed on the input terminals.
- Ensure that the power source circuit breaker is open so that the voltage across the DC power source cable leads is 0 V and that the cable leads do not become active while you are connecting DC power.
- Verify that the DC power cables are correctly labeled
before making connections to the power supply. In a typical power
distribution scheme where the return is connected to chassis ground
at the battery plant, you can use a multimeter to verify the resistance
of the –48V and RTN DC cables to chassis ground:
The cable with very high resistance (indicating an open circuit) to chassis ground is negative (–) and will be installed on the –48V (input) DC power input terminal.
The cable with very low resistance (indicating a closed circuit) to chassis ground is positive (+) and will be installed on the RTN (return) DC power input terminal.
Caution You must ensure that power connections maintain the proper polarity. The power source cables might be labeled
(+)
and(–)
to indicate their polarity. There is no standard color coding for DC power cables. The color coding used by the external DC power source at your site determines the color coding for the leads on the power cables that attach to the DC power input terminals on each power supply.Warning Ensure that the power cables do not block access to switch components or drape where people can trip on them.
Note To supply sufficient power to an EX8208 switch, terminate the DC input wiring on a facility DC source that is capable of supplying a minimum of 60 A at –48 VDC.
To supply sufficient power to an EX8216 switch, terminate the DC input wiring on a facility DC source that is capable of supplying a minimum of 100 A at –48 VDC.
Note A 2000 W DC power supply requires a dedicated 60 A circuit breaker for each input DC feed.
A 3000 W DC power supply requires a dedicated 100 A circuit breaker for each input DC feed.
Note Each power supply input feed must be connected to a dedicated DC power source outlet.
- Install each power cable lug on the DC power input terminal,
securing it first with a locking washer, then with the nut (see Figure 6). Apply between 29 in.-lb
(3.3 Nm) and 31 in.-lb (3.5 Nm) of torque to each nut.
(Use the 3/8-in. [9.5 mm] nut driver or socket wrench.)
Secure each positive (+) DC source power cable lug to the RTN (return) DC power input terminal.
Secure each negative (–) DC source power cable lug to the –48V (input) DC power input terminal.
Each power supply has two independent sets of DC power input terminals (A: –48V A: RTN and B: – 48V B: RTN ). For feed redundancy, each power supply should be powered by dedicated power feeds derived from feed A and feed B. This configuration provides the commonly deployed A/B feed redundancy for the switch.
Note If the power cord tray is installed, you can thread the DC power cables through the power cord tray.
Figure 6: Connecting the Power Supply Cables to an EX8200 Switch - Install the plastic cable cover over each set of power
cables, using the number 2 Phillips (+) screwdriver to tighten
the screw (see Figure 7).
Figure 7: Installing the Plastic Cable Cover on a DC Power Supply in an EX8200 Switch - Ensure that the power supply is fully inserted and latched securely in the chassis. See Installing a DC Power Supply in an EX8200 Switch.
- Repeat Steps 2 through 9 for the remaining power supplies.
Powering On an EX8200 Switch
Before you power on the switch, ensure that:
You have installed all required switch components.
You have installed the required number of power supplies to support redundant operation for the switch configuration (see Calculating Power Requirements for an EX8208 Switch or Calculating Power Requirements for an EX8216 Switch).
You understand how to protect the switch from electrostatic damage (see Prevention of Electrostatic Discharge Damage).
Ensure that you have the following parts and tools available to power on the switch:
An electrostatic discharge (ESD) grounding strap.
An external management device such as a PC.
A cable to connect the external management device to the primary Switch Fabric and Routing Engine (SRE) module's console (CON) port or management (MGMT) port in an EX8208 switch or the primary Routing Engine (RE) module’s console (CON) port or management (MGMT) port in an EX8216 switch.
For connecting a management device to the console port, see Connect a Device to a Management Console Using an RJ-45 Connector. For connecting a management device to the management port, see Connect a Device to a Network for Out-of-Band Management.
To power on the switch:
- Attach the ESD grounding strap to your bare wrist and connect the strap to the ESD point on the chassis.
- Connect the external management device to the primary SRE or primary RE module's management (MGMT) port.
- Turn on the power to the external management device.
- Ensure that the power supplies are fully inserted in the chassis and that each of their handles is flush against the faceplate.
- Ensure that the source power cord is inserted securely
into the appliance inlet for each AC power supply.
If you are using DC power supplies, ensure that the source power cables are connected to the appropriate terminal: the positive (+) source cable to the return terminal (RTN) and the negative (-) source cable to the input terminal (-48 VDC).
- Switch on the site circuit breakers.
- Flip a power supply’s Enable switch to
the on position (ON). See Figure 8. Observe the power supply faceplate LEDs. If the power supply
is installed correctly and functioning normally, the INPUT OK / IN OK and OUTPUT OK / OUT OK LEDs light
and remain constantly lit. The FAIL LED does not light.
Figure 8: Flip the Enable Switch to the ON position - Repeat Step 7 for the remaining power supplies installed in the switch.
- On the external management device, monitor the startup process to ensure that the system boots properly.
After you power on a power supply, wait for at least 60 seconds before you turn it off. After you power off a power supply, wait for at least 60 seconds before you turn it back on.
If the system is completely powered off when you switch on a power supply, the SRE or RE module boots as the power supply completes its startup sequence.
After you power on a power supply, it can take up to 60 seconds for status indicators such as power supply LEDs and the show chassis operational mode CLI command display to indicate that the power supply is functioning normally. Ignore any error indicators that might appear during the first 60 seconds.