FieldWatt
Utility scale solar. NEC calculators, inverter fault codes, SCADA and protection references.
The offline reference and toolkit for the people who commission, maintain, and troubleshoot EV chargers: Level 2 stations and DC fast chargers at public networks, fleet depots, and highway corridors. NEC calculators with worked steps and citations, charger fault families and brand notes, control pilot and OCPP references, and site paperwork that becomes clean PDFs. Built for sites with zero cell signal: everything works offline, forever.
Every charger talks down to the car and up to its network. Almost every failure is power electronics, the vehicle handshake, or the backend. PlugWatt helps you tell which, fast.
Continuous load sizing at 125 percent, EVEMS managed demand with the 2026 exception, service capacity checks, conductor sizing with derates, voltage drop, and the disconnect helper. Every result shows the formula, the worked steps, and the citation for your selected NEC year.
Insulation monitor trips, welded contactors, precharge faults, thermal terminations, handshake failures, and backend timeouts, each with symptoms, likely causes, diagnosis steps, and the safe response. Brand notes for ChargePoint, ABB, Tritium, Alpitronic, Tesla and NACS, BTC Power, Kempower, and Signet.
The hard to find stuff: J1772 pilot states and duty cycles, the CCS and NACS handshake stage by stage, ISO 15118 and Plug and Charge certificates, OCPP versions and messages, and offline authorization behavior.
Six decision trees localize a dead session to power electronics, the vehicle handshake, or the network. Safety critical findings render red with a stop work posture, never a blind reset.
Commissioning with the UL 2231 trip test, preventive maintenance, LOTO and energized work permits, PPE and glove logs, work orders, OCPP configuration records, and JHA tailboards. Photos, signatures, and autofill from your company and site profiles, exported as one site packet PDF.
High voltage DC and arc flash awareness built on NFPA 70E, lockout tagout with capacitor discharge, and glove certification rules per OSHA and ASTM D120, surfaced across the whole app.
The reference library and core calculators are free. PlugWatt Pro unlocks the full calculator suite, all guided trees, and the forms module. No account, no ads, no tracking: see the privacy policy and terms of use.
Same idea, built for other trades: everything bundled, fully offline, no account and no tracking.
Utility scale solar. NEC calculators, inverter fault codes, SCADA and protection references.
Battery storage (BESS). Battery calculators, BMS and PCS fault families, thermal and protection.
Data centers. Methods of Procedure executed step by step, power and cooling calculators.
Fire alarm and life safety. NFPA 72 inspections that become authority ready PDFs, battery calculations.