AmpGuide

SelectivityDesk: Service-to-branch checks, field readings, punch lists, and inspection reports. - Freeze service, panel, feeder, circuit, equipment, and applicable design basis - Capture conductor, protection, load, voltage-drop, and fault-current evidence - Review coordination assumptions without presenting a phone result as certification - Record test readings, exceptions, owner, corrective action, and verification - Export a punch list and inspection brief with source references

NEW: Panel Schedule — document any panel, place breakers space by space with automatic tied-space handling, and export a clean circuit directory for the panel door or an inspection packet. The Calc Hub is now searchable (try an NEC article like 250.66), with pinned Favorites and a Recent row so your go-to calculators are one tap away. Jobs gained a one-tap report export that bundles every saved calculation with the inspection brief. Plus interface refinements throughout.

This update sharpens the interface: the iPad layout now uses a centered, comfortable reading width and an adaptive calculator grid instead of stretching edge to edge. Still fully on-device with no new permissions.

1.3 — Optional Load, Transformer Sizing, Wire Pull Tension New: Optional Method Service Load (NEC 220.82) The faster dwelling service calculation that electricians reach for on remodel and upgrade jobs. Combines all loads, applies 100% to the first 10 kVA and 40% to the remainder, then adds the largest HVAC load at 100% and the EV charger at 125% (continuous). Results save to Jobs. New: Transformer Sizer (NEC 450.3) Enter load in kW and power factor — the calculator finds the next standard kVA size (NEMA ST 20 / IEEE C57.12.91), computes primary and secondary full-load amps, and sizes the overcurrent protective devices per NEC Table 450.3(B) for both primary-only and primary+secondary protection configurations. Includes six common load presets for quick starts. A highlighted grid shows all standard kVA sizes so you can see where your selection lands. New: Wire Pull Tension + Jam Ratio Before you pull, check two things: (1) Pull tension — calculates T = W × L × k using conductor weight and friction coefficient (Southwire Engineering Handbook, 10th ed.), compares against the 0.008 × CM limit for copper or 0.006 × CM for aluminum. (2) Jam ratio — when pulling exactly 3 conductors, flags the 2.8–3.2 danger zone where same-size conductors can wedge in the conduit. Covers #14 through 750 kcmil THHN, EMT/RMC/PVC Sch 40, six friction conditions. Results save to Jobs. Previous releases Version 1.2: Conduit Bender (5 modes) + NEC Wire Color Reference. Version 1.1: Solar PV, EV Charger, Service Load (standard method), Grounding, Short Circuit, Motor FLC, Lighting Load, Bid Estimator. Version 1.0: Wire Size, Voltage Drop, Ampacity, Breaker, Conduit Fill, Box Fill, Ohm's Law, Three-Phase, Jobs.