Mike Dolt Enterprises
Mike Dolt Enterprises
User: Orion231, Location: SW Washington
Asked on: Sunday, May 30, 2021 at 10:21 am EDT
Answered on: Thursday, June 20, 2024 at 11:15 am EDT
Question: I just read about the NEC 2020 new requirement for a whole house surge protector. I am wondering where to place one or more surge protectors as I need to replace my house panel. The issue is the layout of my main power feeds.I live on a farm and two years ago upgraded my feed from the power company to 400 amp service. My circuit layout has power from the street going to a meter panel on my shop. I feed two circuits from the meter through the shop wall to a 200 amp shop panel and to a second house panel that is my manual generator switch/house disconnect/well pump panel inside the shop. The pump is located in the well next to the shop (about 80 feet of wire run to the pump). The house panel feeds a 150 foot run to my house. Because the house is a manufactured home, the 200 amp feed from the shop goes to an outside disconnect/circuit breaker panel. From that panel, the 200 amp service runs to the internal house service panel. All external wire is run in conduit and buried.The house panel is an old Crouse-Hinds (1987 home) and I find that I need to replace the panel in the near future. My dryer kept quitting and I thought it was the dryer. Actually the breaker in the panel due to the poor design of the breaker was overheating and making intermittent contact. It came close to causing a fire so will be replacing the panel with something of new design.So, how many surge protectors are needed and in which panels would they be located? Thanks
Requirement for Whole House Surge Protectors in NEC 2020
NEC 2020 requires a whole house surge protective device (SPD) at the service entrance for any structure with an electric service of 1000 amps or less.
Placement of Surge Protectors
In your case, you have two main power feeds: Feeder 1
Street to meter panel on shop, then to shop panel and house panel inside the shop
Feeder 2
Shop panel to house disconnect/circuit breaker panel outside the house, then to house service panel inside the house
Surge Protector Placement Recommendations Feeder 1
Place one SPD at the meter panel on the shop. This will protect the shop and the house panel inside the shop.
Feeder 2
Place a second SPD at the house disconnect/circuit breaker panel outside the house. This will protect the house service panel and the house itself.
Additional Considerations Well Pump
The well pump is not located at the service entrance. Consider installing a separate SPD at the well pump location for added protection.
Internal House Service Panel
Depending on the design of the house service panel, you may need to install a Point-of-Use SPD at the panel to provide additional protection for sensitive electronics.
Recommended Surge Protector Type
Select a whole house SPD with a UL 1449 rating and a surge current rating appropriate for the size of your electrical service (400 amps in your case).
Conclusion
To comply with NEC 2020 and provide optimal protection for your electrical system, you should install two whole house SPDs: one at the meter panel on the shop and one at the house disconnect/circuit breaker panel outside the house. Consider an additional SPD for the well pump and a Point-of-Use SPD for the internal house service panel if necessary. Flag for review