Feeder tap rules wrapper
Why you care (60 seconds)
Tap rules let you deviate from standard overcurrent protection if you meet strict conditions. Miss one condition and the install fails inspection.
Where people lose time
- Assuming taps are allowed without checking the rule set.
- Mixing up different tap lengths and conditions.
- Forgetting physical protection or termination rules.
This is
The rule in plain language
Feeder taps are permitted when the tap conductor length, protection, and termination conditions match specific rule sets.
When it applies
Any time a feeder conductor is tapped ahead of its overcurrent protection.
What you must do (checklist)
- Identify the specific tap rule being used.
- Keep tap length and routing within the allowed limits.
- Ensure conductor ampacity and termination ratings comply.
- Provide required physical protection and enclosure rules.
Quick examples
- A short tap with the right length and protection can be allowed.
- Long taps have stricter conditions and routing requirements.
This is not
Common misreads
- Treating a tap like a normal feeder without conditions.
- Using tap rules for branch circuits without checking applicability.
What it doesn't cover
- Transformer secondary conductors with their own rules.
- Service conductor taps.
False friends
- A feeder extension is not a tap unless it meets tap conditions.
Exceptions & edge cases
- Different tap rules apply based on length and installation method.
- Some equipment has specific tap allowances in its listing.
Cross-references (NEC map)
- Primary: 240.21
- Secondary: 240.4, 310.16
Exam traps
- Mixing up short and long tap conditions.
- Missing physical protection requirements.
Field notes
- Sketch the tap path and length before pulling conductors.
- Document which tap rule you used for inspections.
AHJ / Local amendments notes (placeholder)
- Add local amendments or interpretations here.
Revision notes
- Draft wrapper created for feeder tap rules.