Why More Than Two Ground Wires Under One Lug Is a Deficiency
When inspecting electrical panels, home inspectors often point out a condition called “double-lugging” or “multi-lugging” ground wires. This happens when more than two grounding conductors are placed under a single lug (the screw terminal on the grounding bar inside the panel). While it may not look like a major concern at first glance, this is considered a deficiency by both home inspectors and electricians — and here’s why.
Safety and Performance Concerns
1. Loose Connections
Each lug is designed to hold a limited number of conductors securely. When multiple wires are stacked together, one or more may not make proper contact, leading to loose connections. Loose connections can generate heat, cause arcing, or create unreliable grounding paths.
2. Reduced Grounding Reliability
The grounding system’s main job is to provide a safe path for electrical faults to return to the earth. If grounding conductors are crowded under one lug, the connection may not perform as intended, increasing the risk of shock or fire hazards.
3. Manufacturer Limitations
Panel manufacturers test and design their equipment to hold only a certain number of wires under each lug. Most allow only one neutral conductor per lug and at most two grounding conductors of the same size per lug. Anything beyond that is not in line with the panel’s listing and labeling, which makes it unsafe.
What the NEC Says
The National Electrical Code (NEC), specifically NEC 408.41, states that each grounded (neutral) conductor must terminate in an individual terminal that is not used for another conductor. While grounding conductors (grounds) have slightly more flexibility, the code and manufacturer installation instructions still restrict how many can go under a single lug. Exceeding this limit is considered improper installation and a code violation.
Why Home Inspectors Call It Out
As home inspectors, our job is to look for conditions that affect the safety, performance, and longevity of the electrical system. Multiple ground wires under a single lug:
- Can signal that the panel was not installed or modified correctly
- Creates a higher risk of electrical issues over time
- Indicates that an electrician should evaluate the panel for proper configuration
Even though the home may appear to function fine, inspectors call this out because electrical safety depends on proper connections, not just whether the lights turn on.
What Homeowners Should Do
If your inspection report notes more than two ground wires under one lug, the solution is usually straightforward:
- A licensed electrician can rearrange the wiring and add a proper grounding bar if needed.
- This helps ensure every connection is secure, code-compliant, and safe.
It’s a relatively minor repair, but it plays a big role in keeping your home’s electrical system safe and reliable.
✅ Bottom Line: More than two ground wires under one lug may seem like a small detail, but it compromises safety, violates today’s NEC standards, and is why home inspectors always call it out. Correcting it is a quick fix that helps protect your home from electrical hazards.
Author: Inspection Time | Aaron – Certified Master Inspector TREC #25498 | NACHI22040459 | LEAD FIRM #NAT-F244506-1 | TDA# 0907507 | Airman Certificate #4902697
