Interactive labs, calculators & simulators
49 browser-based tools across 11 disciplines. No account needed to open a lab. Availability and validation are shown separately on every card.
Filters
Tool results
Box Fill Calculator
Apply the five NEC 314.16(B) counting categories — conductors, clamps, support fittings, device yokes, and equipment grounding conductors — and sta…
- NEC
- BOX FILL
- NEC 314.16
Busway / Bus Duct Insulation & Connection Test Report
Document a complete busway insulation resistance and connection resistance test record from project header through dual-signature review.
- NETA ATS
- NETA MTS
- BUS DUCT
Commercial Load Build-Up Calculator
Apply the correct NEC Article 220 demand factor for each commercial load category — general lighting (220.42), non-dwelling receptacles (220.14(H))…
- NEC
- COMMERCIAL LOAD
- SERVICE LOAD
Conductor Ampacity & Wire Sizing Calculator
Look up conductor ampacity from NEC Table 310.16 on the 90°C column, then cap the result at the terminal temperature rating under 110.14(C).
- NEC
- AMPACITY
- CONDUCTOR SIZING
Conductor Derating & Adjustment Explorer
Apply temperature correction factor from NEC 310.15(B)(2) for the actual ambient temperature and explain why a higher ambient reduces allowable amp…
- NEC
- CONDUCTOR DERATING
- ADJUSTMENT FACTOR
Conduit Fill Calculator
Apply the NEC Chapter 9, Table 1 fill percentage limits — 53% for one conductor, 31% for two, 40% for three or more — to a raceway fill calculation.
- NEC
- CONDUIT FILL
- NEC CHAPTER 9
Continuous Load Sizing Basis Calculator
State the NEC definition of a continuous load (maximum current for 3 hours or more) and explain why the classification triggers the 125% sizing mul…
- NEC
- CONTINUOUS LOAD
- NONCONTINUOUS LOAD
Dwelling Unit Load Calculator
Apply the NEC Standard Method under Article 220 Part III to a single-family dwelling, calculating general lighting load, small appliance branch cir…
- NEC
- DWELLING UNIT
- RESIDENTIAL LOAD
Equipment Grounding Conductor (EGC) Sizing Calculator
Look up the minimum EGC size from NEC Table 250.122 given a known OCPD rating and explain why EGC sizing is based on OCPD rather than load current.
- NEC
- EGC
- NEC 250.122
EV Charger Branch, Feeder & Service Calculator
Apply the NEC Article 625 continuous-load factor to EVSE branch circuit sizing.
- NEC
- EV CHARGER
- EVSE
General Lighting & Receptacle Branch-Circuit Calculator
Look up the general lighting VA/ft² value from NEC Table 220.12 for a given occupancy type and calculate the total general lighting load for a defi…
- NEC
- GENERAL LIGHTING
- RECEPTACLE
Generator, ATS & Emergency Power Sequence Simulator
List the sequence of states from utility loss to stable generator supply and identify timing requirements for each.
- GENERATOR
- ATS
- EMERGENCY POWER
Grounding & Bonding System Visualizer
Distinguish between grounding (earth connection) and bonding (equipotential connection) as defined by NEC Article 250.
- NEC
- GROUNDING
- BONDING
Grounding Electrode Conductor (GEC) Sizing Calculator
Look up the GEC size from NEC Table 250.66 given the largest service-entrance or feeder conductor size and explain why the GEC is sized from the so…
- NEC
- GEC
- NEC 250.66
HVAC & Refrigeration MCA / MOCP Interpreter
Explain the difference between Article 440 (nameplate-driven) and Article 430 (calculation-driven) sizing and identify which applies to hermetic re…
- NEC
- HVAC
- MCA
MCC Inspection & Test Documentation
Complete the 12-item MCC visual and mechanical inspection checklist — from overall cleanliness through wiring and terminations — recording Inspecte…
- NETA ATS
- NETA MTS
- MCC
Motor Branch-Circuit Conductor & OCPD Study Tool
Look up full-load current from NEC Tables 430.248 and 430.250 for single-phase, three-phase, and synchronous motors, and explain why nameplate amps…
- NEC
- MOTOR BRANCH CIRCUIT
- NEC ARTICLE 430
Multiple Motor Feeder & Service Calculator
Apply NEC 430.24 to size a feeder conductor for multiple motors — 125% of the largest motor FLC plus 100% of every other motor FLC plus any non-mot…
- NEC
- MOTOR FEEDER
- NEC 430.24
MV Air Circuit Breaker Test
Document complete MV air circuit breaker nameplate data including maximum voltage (kV), interrupting capacity (kA), ampacity, operating voltage, an…
- NETA ATS
- NETA MTS
- MV CIRCUIT BREAKER
OCPD Sizing Calculator
Apply the NEC 240.4(B) next-standard-size-up rule and identify when it is permitted versus when 240.4(D) imposes a hard cap based on conductor size.
- NEC
- OCPD
- OVERCURRENT PROTECTION
One-Line Diagram Builder & Explorer
Place and connect standard one-line diagram symbols for sources, transformers, breakers, buses, and loads.
- ONE-LINE DIAGRAM
- SINGLE-LINE DIAGRAM
- SLD
Panelboard & Feeder Load Calculation
Identify which NEC Article 220 demand factor applies to each load category — general lighting (220.42), non-dwelling receptacles (220.14(H)), offic…
- NEC
- PANELBOARD LOAD
- FEEDER LOAD
Power System Simulator
Calculate line-to-neutral and line-to-line voltages for both Wye and Delta connections given source voltage.
- THREE-PHASE POWER
- SINGLE-PHASE
- PHASOR DIAGRAM
SCCR / AIC Fault Current Compliance Checker
Distinguish AIC (device interrupting capacity) from SCCR (assembly withstand rating) and explain why both must be checked.
- NEC
- SCCR
- AIC
Service & Feeder Conductor Sizing Calculator
Apply the NEC continuous-load multiplier (125%) to calculate minimum conductor ampacity for feeders and services under Articles 215 and 230.
- NEC
- SERVICE ENTRANCE
- FEEDER CONDUCTOR
Transformer Vector Group & Polarity Visualizer
Interpret an IEC vector group designation (e.g., Dyn11, YNd1) and identify the winding connection and phase shift it encodes.
- IEEE
- DYN11
- YND1
Voltage Drop Calculator & Explorer
Calculate AC voltage drop percentage using conductor resistance and reactance from NEC Chapter 9 tables, applying power factor and temperature corr…
- NEC
- IEEE
- VOLTAGE DROP