Comparison

Fault Current Calculator (PFC) vs PhosphorHertz

Price, ratings, monetisation and update history for both apps, side by side — with what reviewers say about each.

Head to head
About

Fault Current Calculator (PFC)

This app calculates prospective fault current (PFC) in kA and Amps for single and three-phase circuits. It allows users to input any two values (voltage, earth loop impedance, or PFC) to determine the third, aiding in selecting appropriate circuit breaker ratings.

Highlights
  • Calculate PFC from Zs/Ze and Voltage
  • Calculate Zs/Ze from Voltage and PFC
  • Calculate Voltage from PFC and Zs/Ze
  • PFC calculation in kA and Amps
  • Single and three-phase support
  • Input any two values to calculate the third
Features
Read full description

Fault Current Calculator for iPhone and iPad is a fast, free tool for electricians, contractors, and engineers. Calculate Prospective Fault Current (PFC), Prospective Short-Circuit Current (PSCC), and Prospective Earth Fault Current (PEFC). Enter any two known values - voltage, loop impedance (Zs/Ze), or fault current - and the app instantly calculates the third. KEY FEATURES: PSCC and PEFC calculations: Calculate prospective short-circuit current for L-N or L-L faults and prospective earth fault current for L-E faults. Single-phase and three-phase support: Perform fault-current calculations for both system types. Automatic calculations: Enter any two known values to auto calculate the third. Loop-impedance calculator: Calculate Zs or Ze from voltage and prospective fault current. Formula display: See the formula used for each calculation so you can understand and verify the result. Works offline: Use the app in roof spaces, basements, plant rooms, and other locations without a signal. Dark mode and light mode: Maintain a clear display in different site conditions. 16 languages: Fully translated for electricians worldwide (af, ar, de, es, en, fr, hi, id, it, ja, ko, nl, pl, pt, ru, zh). Fast and free: A clean interface designed to deliver results without unnecessary steps. DEFINITIONS: AIC (Ampere Interrupting Capacity), often written as kAIC for kilo-Amperes, is a specific rating for protective devices that open a circuit, such as circuit breakers and fuses. SCCR (Short-Circuit Current Rating) is the maximum fault current that a complete piece of equipment or electrical assembly (like an industrial control panel, switchboard, or HVAC unit) can safely withstand without causing a hazard. Electrical calculations should be independently verified before safety-critical work. Ensure the calculated prospective fault current does not exceed the protective device's rated breaking capacity. For additional tools, upgrade to Electrical Tools & Reference, which includes calculators for kVA, Max Zs, cable sizing, and more. Pro Certs Software - trusted by electricians since 2011.

About

PhosphorHertz

Features
Read full description

PhosphorHz is a real-time HF radio propagation monitor for amateur radio operators. It pulls live space weather data from NOAA's Space Weather Prediction Center and translates it into band-by-band conditions you can act on — right now, from your location. No guesswork. No stale forecasts. Just the numbers, rendered in a retro CRT phosphor display that would look at home in a Cold War listening post. BAND CONDITIONS See at a glance which HF bands are open, marginal, closed, or blacked out. Conditions are calculated from real-time solar flux, geomagnetic activity, and X-ray flux data — not generic regional forecasts. Each band shows your local status plus path-specific conditions to every DX target you configure. MUF CALCULATION The Maximum Usable Frequency for a 3000km reference path from your QTH, derived from Solar Flux Index, solar zenith angle, and depressed by geomagnetic activity. Individual MUFs are calculated for each great-circle path to your DX targets, because the ionosphere doesn't care about averages. SOLAR INDICES All the numbers that matter, updated in real time: Solar Flux Index (SFI) with 30-day trend chart Planetary Kp Index with 24-hour bar chart Estimated Sunspot Number (SSN) GOES X-ray flux class and latest flare detection Solar wind IMF Bz component NOAA R/S/G scales (Radio Blackout, Solar Radiation, Geomagnetic Storm) Running A-index and solar wind Bt Each index includes a plain-language assessment: is the F2 layer well ionised? Is the geomagnetic field quiet or disturbed? Is the solar wind coupling or shielded? 3D GREYLINE GLOBE A SceneKit globe shows the solar terminator — the boundary between day and night — in real time. The greyline (twilight zone along the terminator) is where lower-band DX propagation is enhanced, and it's rendered as an amber band you can see at a glance. The globe displays coastlines, your QTH position, DX target locations, and great-circle paths coloured by band condition. Drag to rotate. Double-tap to recentre on your station. Hit play to watch the Earth spin. SPACE WEATHER ALERTS NOAA SWPC alerts and warnings filtered for HF relevance. Flare events, geomagnetic storms, radio blackouts — the alerts that actually affect your ability to make contacts, with full detail on tap. DX TARGETS Configure up to five target regions. PhosphorHz calculates path-specific propagation for each one, using great-circle geometry and the MUF at the midpoint of each path. What's open to Japan might be closed to South America — and now you can see both at once. FEATURES Real-time data from NOAA SWPC (public domain, no API key required) Band conditions for 160m through 6m Path-specific propagation to multiple DX targets 3D interactive greyline globe with terminator visualisation Sunrise/sunset times and countdown to next solar event Day/night/greyline status at your QTH Kp index 24-hour bar chart SFI 30-day trend line Full space weather alert log with 30-day history Maidenhead grid locator display Automatic location detection or manual grid entry Green phosphor and amber phosphor CRT themes CRT scanline overlay effect Designed for iPhone, portrait orientation No ads. No tracking. No subscription. Part of the Phosphor suite: PhosphorWX (aviation weather), PhosphorRad (radiation monitoring), PhosphorSol (space weather), and PhosphorOrbit (satellite tracking). 73 de PhosphorHz.

Screenshots

Fault Current Calculator (PFC)4 screens
PhosphorHertz4 screens

Verdict

The call

The clearest difference is price: Fault Current Calculator (PFC) at Free against PhosphorHertz's $0.99. Fault Current Calculator (PFC) also leads on iOS requirement (15.0 vs 26.2). PhosphorHertz's advantage is ads (none vs shown) and update cadence (every 4 months vs every 14 months). On in-app purchases and device support there is nothing between them.

Scored on Price · Rating · Positive reviews · Number of ratings · Update frequency · Ads · In-app purchases · Monetization · Best chart rank · Devices · Requires iOS

CostPrice · In-app purchases · Ads · Monetization

Fault Current Calculator (PFC) is free to download; PhosphorHertz costs $0.99 up front. Neither carries in-app purchases, so what you see is what you pay.

UpkeepUpdate frequency

Fault Current Calculator (PFC) ships an update every 14 months, PhosphorHertz every 4 months. The most recent releases landed on November 6, 2026 and October 31, 2026 respectively.

Scorecard4 real differences · 6 level
Fault Current Calculator (PFC) versus PhosphorHertz: the parameters behind the verdict, then further details
ParameterFault Current Calculator (PFC)PhosphorHertz
PriceFree — better$0.99
Rating1.0 (2 ratings) — better—
Positive reviews33.3% of reviews—
Number of ratings2 — better—
Update frequencyEvery 14 monthsEvery 4 months — better
AdsYesNo — better
In-app purchasesNoNo
MonetizationPaid—
DevicesiPhone, iPad, iPod — betteriPhone, iPad
Requires iOS15.0 — better26.2
Further details — not scored
Size10 MB5 MB
Age rating4+4+
DeveloperPro Certs Software LtdStuart Woolley

In-app purchases

None

Fault Current Calculator (PFC)

No in-app purchases

None

PhosphorHertz

No in-app purchases

Questions

Is Fault Current Calculator (PFC) free?
Fault Current Calculator (PFC) is free to download, with no in-app purchases.
Is PhosphorHertz free?
PhosphorHertz costs $0.99, with no in-app purchases.
Do Fault Current Calculator (PFC) or PhosphorHertz have ads?
Fault Current Calculator (PFC) shows ads; PhosphorHertz does not.
Which is updated more often, Fault Current Calculator (PFC) or PhosphorHertz?
Fault Current Calculator (PFC) ships an update every 14 months, and PhosphorHertz every 4 months. Most recently, Fault Current Calculator (PFC) was updated on November 6, 2026 and PhosphorHertz on October 31, 2026.

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