Showing Posts From
Nec 31012
This tag page collects 3 TradesQuote articles related to Nec 31012. Use it to browse contractor-focused guidance on sizing, code, cost, diagnostics, and estimating without hunting through the full blog archive.
Each post below is written for people who bid and run trade work — HVAC and electrical contractors, estimators, and technicians who need clear explanations they can apply on the next job. Skim the summaries, open the guides that match your question, then follow related calculator links when you need interactive numbers.
Featured reading in this collection includes: Sub Panel Sizing: Feeder Wire, Breaker, Neutral, and Ground; What Size Wire for a 100 Amp Sub Panel?; 200 Amp Service Wire Size: Copper vs Aluminum and the 83% Rule. Open any article for full detail, examples, and links to free tools that support faster estimating.
Looking for a broader topic? Browse all tags from the tags index, or jump to HVAC and electrical categories for curated topic hubs. TradesQuote also offers free calculators and an AI estimator when you are ready to turn a job description into a line-item quote.
Guides in this tag
- Sub Panel Sizing: Feeder Wire, Breaker, Neutral, and Ground
"4 AWG for a 100 A sub panel" is wrong for a garage - that needs 3 AWG copper. Why the Table 310.12 83% allowance doesn't reach an ordinary subpanel, plus the four-wire feeder and the bonding screw.
- What Size Wire for a 100 Amp Sub Panel?
The answer depends on whether the feeder carries the whole house. Ordinary subpanel: 3 AWG copper or 1 AWG aluminum from Table 310.16. Whole-dwelling feeder: 4 AWG copper under the 83% rule. Plus ground size, neutral, and the bonding mistake.
- 200 Amp Service Wire Size: Copper vs Aluminum and the 83% Rule
A 200 amp dwelling service takes 2/0 copper or 4/0 aluminum - smaller than the ampacity table suggests, because Table 310.12 permits 83% sizing. Where that allowance applies, the GEC size, and the neutral.
Related resources
- 05 Aug, 2026
Sub Panel Sizing: Feeder Wire, Breaker, Neutral, and Ground
"4 AWG for a 100 A sub panel" is wrong for a garage - that needs 3 AWG copper. Why the Table 310.12 83% allowance doesn't reach an ordinary subpanel, plus the four-wire feeder and the bonding screw.
- 03 Aug, 2026
What Size Wire for a 100 Amp Sub Panel?
The answer depends on whether the feeder carries the whole house. Ordinary subpanel: 3 AWG copper or 1 AWG aluminum from Table 310.16. Whole-dwelling feeder: 4 AWG copper under the 83% rule. Plus ground size, neutral, and the bonding mistake.
- 03 Aug, 2026
200 Amp Service Wire Size: Copper vs Aluminum and the 83% Rule
A 200 amp dwelling service takes 2/0 copper or 4/0 aluminum - smaller than the ampacity table suggests, because Table 310.12 permits 83% sizing. Where that allowance applies, the GEC size, and the neutral.
Frequently asked questions
Common questions about Nec 31012 guides on the TradesQuote blog.
What will I find under Nec 31012?+
This tag lists 3 published guides tagged or categorized as Nec 31012. Topics typically include sizing, cost estimating, diagnostics, and practical contractor workflows tied to that subject.
Are these articles a substitute for code or engineered design?+
No. TradesQuote guides explain concepts and estimating shortcuts so you can work faster and communicate clearly. Always follow applicable codes, manufacturer instructions, and professional engineering requirements for the job.
How do these pages relate to TradesQuote tools?+
Many articles link to free HVAC or electrical calculators and to TradesQuote estimating features. Use the guides to understand the topic, then use the tools to produce numbers for proposals and field checks.