DC Master Ground Busbar (MGB) Installation & Commissioning Checklist

This article is about DC Master Ground Busbar MGB Installation & Commissioning Checklist of DC System as per International Codes and standards.

DC Master Ground Busbar Installation & Commissioning Checklist

1. Verify that the installed MGB is a copper ground bar and located within the communications equipment room. The minimum size shall be 6 mm x 102 mm x 500 mm. Make all grounding connections to the MGB using two-hole approved copper terminal lugs.
2. Verify that the installed MGB meet the minimum size of 6 mm x 102 mm x 500 mm and the required two-hole for making all grounding connections to the MGB using two-hole approved copper terminal lugs are provided.
3. Verify that the MGB is located as close as possible to the AC service and outside plant main distribution frame, without interfering with cable structures and support.
4. Verify that the location of the MGB is identified on the building drawings and equipment layout plans, and on the bar itself.
5. Verify that the MGB is bonded to the building ground grid (AC power ground) through two buried leads from opposite sides of the ground grid. The leads shall be a minimum of 4/0 AWG (120 mm²) bare tinned-copper conductors.
6. Ensure that the two leads are installed in PVC conduit. When the PVC conduit is used in areas where it would be exposed to sunlight, it must be a type that is resistant to ultraviolet rays
7. Ensure that bends in ground conductors are kept to a minimum on all unavoidable bends. Verify that the minimum acceptable bending radius of 300 mm for the installed sizes 4/0 AWG leads is maintained.
8. Ensure that the MGB is divided to the following zones:
   “”P”” surge producers (such as interior radio equipment including cable trays that are connected to radio equipment, Cable Shield/Cable Vault Ground Bar and MDF/Entrance Cable Protector Ground Bar)
   “”A”” surge absorbers (both ground leads coming from the opposite sides of the ground grid)
   “”N”” non-isolated equipment (DC Power system positive return bus, computer floor, communication racks and cable trays)
   “”I”” isolated equipment (electronic switching equipment & transmission systems and terminal Equipment)
9. Verify that these zones are permanently labeled on the MGB and on the building drawings.”
10. Ensure that the AC distribution system is not connected to the building ground grid through the MGB.

Standards Codes and References for DC Master Ground Busbar Installation

SAES-T-795 ” Communication DC Power System