Mike Dolt Enterprises
Mike Dolt Enterprises
User: carryyourbooks, Location: Tennessee
Asked on: Tuesday, April 12, 2011 at 1:25 am EDT
Answered on: Tuesday, May 14, 2024 at 4:04 am EDT
Question: i have a service for a 4 unit apartment bldg. the riser is 400 amps that comes down from weatherhead into 8x8x60 gutter box. out of the gutter box, there are 5 meter sockets that feed (5) 125 amp load centers. i have installed gec on the panels to the ground rod. do i need to to install a #2 thhn from the gutter to ground rod. the 4" riser is mounted in a myers hub and the meters are connected via offset nipples. by the way, the service is 240 volt, single phase. thanks.
Yes, a #2 THHN conductor should be installed from the gutter to the ground rod.
Grounding Requirements for Buildings with Multiple Meter Sockets
According to the National Electrical Code (NEC), Article 250.24(A)(1), all service equipment, including meter sockets, must be connected to a grounding electrode system.For a 4-unit apartment building with multiple meter sockets, a grounding electrode system must be installed. This typically consists of a ground rod driven into the earth and a grounding conductor connected to the ground rod and all grounding points in the service equipment.
Grounding Path from Gutter to Ground Rod
The grounding electrode conductor (#2 THHN) provides a low-resistance path for fault currents to flow from the gutter to the ground rod. This helps protect personnel from electric shock and prevents damage to equipment.
Installation Requirements
The #2 THHN conductor must be installed as follows: Connect one end to the grounding terminal in the gutter box. Run the conductor down and connect it to the ground rod using a grounding clamp. Ensure that the conductor is protected from physical damage and corrosion.
Additional Grounding Considerations: The meter sockets should also be connected to the grounding electrode system using grounding busbars or jumper wires. The panelboards should be bonded to the grounding electrode system through the equipment grounding conductors. Verify that all connections are tight and made according to NEC requirements. Flag for review