User: justanotherone, Location: Vermont
Asked on: Wednesday, June 4, 2025 at 6:03 pm EDT
Answered on: Wednesday, June 4, 2025 at 6:13 pm EDT
Question: Property inspector here- central VT without code enforcement to set the stage.I have a meter that has a 4 wire SER feeding the main service panel, which is located about 25-30 feet away. The SER runs from the exterior meter directly inside and through the crawl space and up to the meter located in a closet. My understanding is that his should be a 3 wire SEU and then a bond of the neutrals and ground should occur inside the service panel or a disconnect needs to be installed behind the meter. Also the grounds and neutrals are bonded and terminate on the same bus bar inside the service panel. Am I wrong? An electrician here says I am. Please excuse any wrong terminology. Thank you.
You've accurately identified a few potential issues with the service configuration, and your understanding aligns with generally accepted electrical practices and the NEC (National Electrical Code). Here's a breakdown of your concerns and why they might be valid
Here's the situation you described:
4-wire SER cable
From the meter to the main panel.
Distance
25-30 feet from meter to panel.
Location
Crawl space and closet.
Ground/Neutral Bond
Bonded at the service panel.
Here's why your concerns are valid, and some points to consider
SER vs. SEU and the Neutral-Ground Connection
SER (Service Entrance Cable, Round)
This cable can be used for both service entrance and feeder applications. However, the key is how the neutral is handled. The NEC differentiates between "service equipment" and "separately derived systems."
SEU (Service Entrance Cable, Unarmored)
This is typically a 3-wire cable and generally not appropriate for feeding directly from a meter to a panel without a disconnecting means at the meter.
Your Concern
You're right to be concerned about the continuous run of a 4-wire SER cable from the meter to the main panel without a disconnecting means at the meter. Here's why:
Service Disconnect Requirement
NEC requires a readily accessible disconnecting means (a main breaker or fused disconnect) for the entire service. This disconnect must be located at a convenient and accessible location either outside or just inside where the service conductors enter the building.
Neutral-Ground Bonding
The neutral and ground must be bonded only at the service disconnect location. Since you have the bond in the main panel, the main panel is acting as the service disconnect.
Potential Problem
This raises questions about having a service disconnect not at the meter.2.
The Electrician's Counter-Argument
The electrician is possibly thinking that as long as the 4-wire SER cable is correctly used for a feeder, it is permitted. And, they may see the panel as acting as the service disconnect.3.
Specific NEC Codes to Reference
NEC 230.70(A)(1)
Location of disconnecting means. It must be readily accessible.
NEC 250.24(A)(5)
Grounding of Service-Supplied Alternating-Current Systems. The neutral-ground bond must occur at the service equipment.
In summary
You are correct to question the configuration. The lack of a proper service disconnect before the cable enters the building is a significant safety concern. The electrician may be missing the point of having a service disconnect located closer to the meter. Even if the electrician is correct in their application of the NEC code, the overall safety concern is valid.
Recommendations
Further Investigation
Contact Local Authority
Even without formal code enforcement, there might be a building department or electrical inspector you can consult for an informal opinion.
Detailed Photos
Take extensive photos of the entire installation, including cable markings, the meter base, the panel, and the grounding/bonding setup.2.
Consult Another Electrician
Get a second opinion from a different licensed electrician.3.
Documentation
Clearly document your findings in your inspection report, noting the potential code violations and safety concerns.4.
Recommendation to Client
Advise your client to have a licensed electrician evaluate the service and make any necessary corrections to ensure compliance with the NEC and local regulations.
Important Disclaimer: I am an AI chatbot and cannot provide professional electrical advice. My response is for informational purposes only and should not be substituted for the guidance of a qualified and licensed electrician. You are responsible for your own safety and your client's safety. Flag for review