NEC 230.95: Ground-Fault Protection of Equipment for Services
In large commercial electrical systems, ground faults can be catastrophic. NEC 230.95 exists to reduce the risk of fire, equipment damage, and extended outages by requiring ground-fault protection of service equipment under specific conditions.
For electrical contractors working on 480Y/277V services, this is one of the most closely inspected NEC sections — and one of the easiest to fail if misunderstood.
👉 If you’re new to the Code structure, start with our NEC Overview: What It Is and Why It Matters.
👉 For system context, review NEC Services and Feeders Explained before diving into this service-level protection requirement.
What NEC 230.95 Requires
NEC 230.95(A) requires ground-fault protection of equipment for services that meet all of the following conditions:
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Solidly grounded wye system
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More than 150 volts to ground
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Not exceeding 1000 volts phase-to-phase
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Service disconnect rated 1000 amps or more
In practice, this almost always applies to 480Y/277V commercial services.
⚠️ This protection is not intended to protect people — it protects equipment and the electrical system.
What Ground-Fault Protection of Equipment Does
Unlike GFCI devices, ground-fault protection of equipment:
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Detects low-level ground faults
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Trips the service disconnect before fault current escalates
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Reduces fire risk caused by sustained arcing faults
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Protects switchgear, transformers, and feeders
This is critical in high-fault-current commercial environments.
How NEC 230.95 Fits with Other NEC Articles
NEC 230.95 does not stand alone. It must be coordinated with several other articles:
Service Disconnect Rules
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NEC 230.71 – Service Disconnecting Means
(Six-disconnect rule and grouping requirements)
Feeder Protection
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NEC 215.10 – Ground-Fault Protection of Feeders
(Applies downstream of the service)
Feeder Sizing
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NEC 215.2 – Minimum Rating and Size of Feeder Conductors
Load Calculations
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NEC 220.42 – General Lighting Load Calculations
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NEC 220.87 – Determining Existing Loads
Inspectors expect all of these sections to work together as a system.
Coordination Is Mandatory (Not Optional)
NEC 230.95 requires that ground-fault protection be selectively coordinated.
That means:
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The service GFP must not trip before feeder GFP
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Downstream faults should clear without dropping the entire building
Improper coordination is one of the most common reasons large commercial projects get red-tagged.
Where NEC 230.95 Does NOT Apply
Ground-fault protection of services is not required for:
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Ungrounded systems
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Delta systems
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Services under 1000A
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Systems 150V or less to ground
This distinction is critical during design — don’t assume every service needs GFP.
Common Contractor Mistakes
❌ Installing GFP on services that don’t require it
❌ Failing to coordinate service and feeder protection
❌ Confusing GFP (equipment protection) with GFCI (personnel protection)
❌ No documentation of trip settings
❌ Missing or unclear labeling on service equipment
All of these almost guarantee inspection delays.
Labeling Requirements (Often Missed)
NEC 110.22 requires service equipment with ground-fault protection to be clearly and durably labeled.
Labels should identify:
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Presence of ground-fault protection
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Service disconnect identification
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Voltage and arc-flash hazards
✅ At Print Pro, we supply NEC-compliant service equipment labels, arc-flash labels, and disconnect placards designed specifically for large commercial services.
Pro Tips for Contractors
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If your service is 480Y/277V and ≥1000A, assume NEC 230.95 applies until proven otherwise.
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Always coordinate service GFP with feeder GFP (see NEC 215.10).
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Document trip settings — inspectors frequently ask for proof.
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When possible, install one main service disconnect instead of multiple (simplifies coordination).
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Label service equipment early — not during final inspection.
Conclusion
NEC 230.95 plays a critical role in protecting commercial electrical systems from destructive ground faults. For contractors, compliance requires more than installing a relay — it demands coordination, documentation, and clear identification.
To understand how this fits into the larger NEC framework, review:
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