Extech CT70 GFCI and AC Circuit Analyzer

The CT70 is built to assist electricians, inspectors and maintenance professionals in assessing the safety and capability of AC receptacle circuits. It plugs into a standard three-wire outlet and performs two main functions: first, an AC load test where selectable loads (typically 12 A, 15 A or 20 A) are applied, and measurements are taken for unloaded and loaded line voltage, voltage drop, line impedance and peak line voltage. Second, outlet-tester functions check wiring integrity and protective features — including measuring neutral-to-ground voltage, checking hot/neutral/ground impedance, detecting open or reversed wiring and measuring trip time and trip current of GFCI outlets. The CT70 supports circuits from 90 to 240 V AC at 45-65 Hz, with peak line-voltage measurement up to 350 V and voltage-drop read-out as a percentage. It features a large back-lit LCD display, colour-coded pass/fail indicators, and housing designed for field use with a built-in test cord. In practical use it allows one person to quickly verify whether an outlet circuit can sustain its rated load, identify wiring faults, assess grounding integrity and validate whether a GFCI protection device tripworks — all of which help ensure safety, compliance and system reliability.

Features

• AC load-tester capability with selectable loads (12 A, 15 A, 20 A) allowing assessment of how the outlet circuit performs under real-load conditions.

• Measurement of unloaded and loaded AC line voltage, calculation of voltage drop (%) and line impedance to assess circuit health and conductor sizing.

• Outlet-tester functionality: checks neutral-to-ground voltage, hot/neutral/ground impedance, detects open or reversed wiring and evaluates GFCI trip time and currant

• Peak line-voltage measurement (up to 350 V) and circuit frequency measurement (45-65 Hz range) for comprehensive insight into supply conditions.

• Large field-friendly display with colour pass/fail alerts, compact size (~203 × 71 × 51 mm) and light weight (~317 g) for portability.

• Simple plug-in test cord (North-American 3-prong) for direct connection to standard receptacles; ready to use out of the box.

Includes

• AC Circuit Load Tester
• AC Test Cord (standard North American 3-Prong Plug)