Built for the substation, not the office.
CT / VT Calculator
Ratio, secondary current, burden, knee point — instant.
Commissioning Checklist
Pre-built tests with progress tracking and export.
Relay Quick Reference
ANSI codes, 50/51, 87T, 21, 79 — explained fast.
Offline Field Notes
Cached locally. Sync when you get bars back.
Stop hunting through PDFs on the panel.
Punch in ratios, burdens and fault levels — get secondary current, voltage and knee-point in under a second. No spreadsheets. No flipping between apps.
- CT ratio, secondary current, burden VA
- Knee-point voltage and ALF estimates
- VT ratio and secondary phase voltages
- Copy any result straight into a note
Track every test, even with gloves on.
Big tap targets. Pre-built test sequences for protection schemes. Progress bar so you and the witness know exactly what's left.
- Pre-built lists for transformer, line and feeder protection
- Step-by-step with pass / fail / N/A
- Auto-saves locally — survives a dropped phone
- Export to share with the commissioning report
Every ANSI device number, one tap away.
50, 51, 87T, 21, 79, 50BF, 67N — what it does, why it picks up, what to look for. Written by engineers who've actually been on the panel.
- ANSI device numbers and IEC equivalents
- Plain-English explanation of operating principle
- Common settings ranges and gotchas
- Searchable, browsable, fully offline
Install once. Works in the basement, the yard, the back of a control house.
P&C Field Pro is a PWA — it installs from your browser, runs full-screen, and every tool you've seen above works without a connection. Notes sync the moment bars come back.
For every job on the panel.
Commissioning
Walk down a new bay with a structured checklist and instant CT math.
Troubleshooting
Look up an unfamiliar ANSI code and capture findings in a field note.
Maintenance Outages
Run a repeatable test plan, log results and email them when you get signal.
Quick answers.
Does it really work offline?+
Yes. Every tool — calculators, checklists, reference and notes — runs without a connection. Notes sync to your account as soon as signal returns.
Is this an App Store app?+
No download required. P&C Field Pro is a PWA — you add it to your home screen from the browser and it behaves like a native app, full-screen and offline.
Can I cancel anytime?+
Yes. You can cancel from inside the app in one tap. You keep access until the end of your current billing period.
What about iPads and tablets?+
It runs on any modern browser — iPad, Android tablets, even rugged Windows tablets in a control house.