In this section:
Grounding the DSC Platform hardware can vary depending on the site and national and/or local safety codes and practices.
The copper grounding bar is installed in the rear of the cabinet, left-side (approximately 77 x 1 x 0.25 inches). This grounding bar has 48 1/4-20 tapped holes for grounding connections from the PDU and the shelves.
The required hardware for the various connections is not supplied with the DSC Platform, but recommendations for this hardware are made for the in the following sections.
Use a licensed electrician to connect power and ground to the DSC Platform. The PDU and each shelf include ground terminals that must be properly connected. A separate ground must be connected to each shelf and to the PDU. Actual connections depend on the site and national and/or local safety codes and practices. The following topics address these connections but provide example connections only.
The equipment rack must be grounded in accordance with Article 250 of the National Electrical Code (NEC), and with any other national or local safety codes and practices that apply in your area. Each grounding stud on the DSC Platform must be connected directly to the grounding point by a single length of grounding wire. Do not connect grounding wires together.
Before making any connections to the DSC Platform, the cabinet must be grounded as follows:
The cabinet grounding bar must be connected to the floor grounding bus or Main Facility grounding bus, depending on the facility grounding design, and test result performed by the installation technicians. #2 AWG cables are recommended to compensate for longer cable runs, and higher resistance. It is also recommended that various sizes of lugs, bolts, nuts, star and regular copper washers are available at the time of the installation to adopt the grounding bar for proper grounding as required.
The following table provides a summary of the recommended Power Distribution Unit (PDU) grounding connection hardware between the PDU and the grounding bar.
DSC 8000 PDU Grounding Hardware Summary (Example)
Unless otherwise indicated, the items listed in this table are not supplied with the DSC Platform.
Item | Specifications |
---|---|
Grounding Cables | One 8 AWG grounding cable per shelf with a Panduit LCD8-14A-L (or equivalent) lug on each end. The grounding cable is unshielded stranded copper wire, and has insulation that is green with a yellow spiral stripe1. |
Grounding Cable Length | As required. |
Hardware | 1/4-20 x 1/2 Hex Serr Flange screws |
1At the time this document was published, the electrical standards in the United States used a grounding cable that is identified by its green color and yellow spiral stripe. Make sure that you use equivalent cabling for the electrical code of your country.
The following figure illustrates the example PDU grounding connections.
Grounding Connection on the PDU (Example for one side)
The following figure illustrates an example of the PDU grounding connection to the grounding bar.
PDU Grounding Connection to the Grounding Bar (Example for one side)
Start
Insert each end of the cable into a 6.86 mm (1/4 in.) double main earthing lug such as an AMPOWER II, 4 AWG terminal, AMP P/N 606209 or equivalent, and using the appropriate crimping tool for this terminal, crimp the terminal onto the cable end.
The closest metric equivalent for a 1/4 in. ring terminal is a ring terminal for an M6 stud. This ring terminal has a 6.86 mm hole.
Each shelf of the DSC Platform platform must be independently grounded to the grounding bar.
The following table provides a summary of example grounding hardware for each shelf. Unless otherwise indicated, the items listed in this table are not supplied with your hardware.
Shelf Grounding Hardware Summary (Example)
Item | Specifications |
---|---|
Grounding Cables | Two 8 AWG grounding cables with 6.86 mm (1/4 in) Tyco 55621-1 ring terminals per shelf. The grounding cables are unshielded stranded copper wire, and have insulation that is green with a yellow spiral stripe1. |
Grounding Cable Length | As required. |
Hardware | 1/4-20 x 1/2 Hex Serr Flange screws (Hardware to connect grounding cables to grounding bar). Notes:
|
1At the time this document was published, the electrical standards in the United States used a grounding cable that is identified by its green color and yellow spiral stripe. Make sure that you use equivalent cabling for the electrical code of your country.
The following figure a shows the location of the shelf grounding posts.
Shelf Grounding Post
If the DSC Platform DC grounding post terminals are connected to the supply circuit ground, all of the following conditions must be met to comply with Underwriter Laboratories (UL) requirements:
The grounding post terminal connection should be installed prior to the application of power or peripheral connections to earth ground, and should never be disconnected while power or peripheral connections exist.
For additional grounding requirements, see Grounding Requirements.
Start
Fit the double-hole terminal that is now securely crimped to the 8 AWG cable to both grounding posts.
The following figure illustrates an example for grounding the cabinet door to the grounding bar. #8 AWG cable is recommended with #8 single or double hole lug and star washer. Heat shrink tube and heat gun are required for the installation.
Depending on your build option, this procedure may have already been completed.
Cabinet Door Grounding Connection
The DSC Platform cabinet should be connected to the grounding bar similarly as the cabinet door (see preceding section).
Depending on your build option, this procedure may have already been completed.