TrueFault: Fault Current Calc
Short Circuit & AFC Calculator
Free · In‑App Purchases · Designed for iPad. Not verified for macOS.
TrueFault Pro is a one-time purchase — buy once, unlock forever. No subscription, nothing renews.
TrueFault is an offline available fault current calculator for electricians, built around a five-step wizard that walks you from your system to a result you can read and check.
The wizard guides you through:
1. System — pick single-phase or three-phase.
2. Primary fault current — enter the utility available fault current feeding your service.
3. Transformer — enter the transformer rating, voltages, and impedance (%Z), with tolerance handling.
4. Path to the fault — build the conductor run to the point you care about.
5. Result — see the available fault current along with the inputs, assumptions, and warnings behind it.
Because TrueFault works entirely on-device, you can run a check on a job site, in a switchgear room, or anywhere without signal. Nothing about your calculation has to leave your phone.
Free and Pro:
- Free covers single-phase available fault current checks — system, primary fault current, transformer, conductor path, and a reviewable result with visible assumptions and warnings.
- TrueFault Pro unlocks three-phase system calculations.
TrueFault Pro is an auto-renewable subscription:
- Monthly: $0.99 per month
- Yearly: $4.99 per year
The yearly plan is shown by default because it is the lower yearly cost. Subscriptions are billed to your Apple ID. Billing, renewal, and cancellation are managed in your Apple ID account settings; renewal occurs unless auto-renew is turned off at least 24 hours before the end of the current period. The free single-phase calculator stays available whether or not a subscription is active.
TrueFault is a field aid. Results are drafts to verify before use. It is not a stamped engineering calculation and does not replace code review, engineering judgment, utility documentation, manufacturer data, field and nameplate review, or verification by a qualified professional. You are responsible for confirming utility data, equipment nameplates, conductor details, installation conditions, and applicable code or engineering requirements.
Terms of Use (EULA): https://www.apple.com/legal/internet-services/itunes/dev/stdeula/
Privacy Policy: https://fault.509electric.com/privacy
Ratings & Reviews
- This app hasn’t received enough ratings or reviews to display an overview.
TrueFault Pro is now a one-time purchase: unlock every fault-current feature with a single purchase — no subscription. Buy once, unlock forever. Includes stability and performance improvements.
The developer, Nicole Nalley, indicated that the app’s privacy practices may include handling of data as described below. For more information, see the developer’s privacy policy .
Data Not Collected
The developer does not collect any data from this app.
Accessibility
The developer has not yet indicated which accessibility features this app supports. Learn More
Information
- Seller
- Nicole Nalley
- Size
- 1.9 MB
- Category
- Productivity
- Compatibility
Requires iOS 15.0 or later.
- iPhone
Requires iOS 15.0 or later. - iPad
Requires iPadOS 15.0 or later. - iPod touch
Requires iOS 15.0 or later. - Mac
Requires macOS 12.0 or later and a Mac with Apple M1 chip or later. - Apple Vision
Requires visionOS 1.0 or later.
- iPhone
- Languages
- English
- Age Rating
4+
- 4+
- In-App Purchases
Yes
- TrueFault Pro Unlock $6.99
- Copyright
- © Copyright 2026 509 Electric LLC