HHTraff

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About this app

HHTraff is a free toolkit for electrical and traffic-signal field
technicians working under New Zealand and Australian wiring rules.

CALCULATORS — all offline, all free
• Cable Sizer — pick the smallest cable that handles the load with
temperature and grouping derating applied. Common preset wiring
scenarios make it fast for everyday jobs.
• Voltage Drop — calculate drop using the mV/A/m method for single
and three-phase circuits, with live max-length and max-load
readouts so you can see how much headroom you have.
• Circuit Check — verify a cable, breaker, load and length combo
against AS/NZS 3000 voltage drop limits in one screen.
• Earth Fault Loop — confirm Zs is low enough for the protective
device to disconnect, with both measured and calculated modes.

Calculations are based on AS/NZS 3000 and AS/NZS 3008 reference
data. Always verify against the wiring rules that apply in your
jurisdiction — HHTraff is a reference tool, not a substitute for
the standards or for a qualified electrical worker.

REFERENCE TOOLS — also offline, also free
• Unit Converter — quick conversions for everyday field work:
cable cross-section (mm² ↔ AWG ↔ kcmil), power (W, kW, HP, BTU/h),
temperature (°C, °F, K), and length, area and volume in both
metric and imperial units. Live two-way conversion as you type.
• Cable Colours — regional wire colour reference for NZ/AU,
UK, US (NEC) and EU (CENELEC) installations, plus T568A vs T568B
RJ45 4-pair UTP pinouts for structured-cabling work. Read-only,
no internet needed.

DIAGNOSTIC TERMINAL
HHTraff includes a VT100-style serial terminal for connecting to
traffic-signal controllers (ATSC4, TOPAS 2500B and others) over
USB or Bluetooth. Field technicians can review controller menus,
capture log files to the device, and browse a built-in command
quick reference for common controller families.

WHO IT'S FOR
• Registered electricians on residential, commercial and industrial
jobs in New Zealand and Australia
• Traffic-signal technicians servicing intersection cabinets
• Structured-cabling and data installers needing a quick T568A/B
reference on site
• Apprentices learning the AS/NZS calculation methods

PRIVACY
HHTraff does not collect personal data, location, or analytics.
See phaselogic.app/privacy for full details.

What’s new

HHTraff 1.2.4 fixes a crash when opening Notes on some devices.