# Fault Current Calculator (PFC) vs Cornerstone.Network MyLocken

The clearest difference is review sentiment: Cornerstone.Network MyLocken at 100% against Fault Current Calculator (PFC)'s 33%. Cornerstone.Network MyLocken also leads on monetization model (free vs paid) and ads (none vs shown). On price, in-app purchases, device support and iOS requirement there is nothing between them.

Both are free to download. Neither carries in-app purchases, so what you see is what you pay.

Fault Current Calculator (PFC) ships an update every 14 months, Cornerstone.Network MyLocken every 5 months. The most recent releases landed on October 24, 2026 and October 30, 2026 respectively.

## The numbers

| Metric | Fault Current Calculator (PFC) | Cornerstone.Network MyLocken |
| --- | --- | --- |
| Price | Free | Free |
| Rating | **[1.0 (2 ratings)](https://appshunter.io/ios/app/fault-current-calculator-pfc/id577611194/reviews)** | — |
| Number of ratings | **2** | — |
| Positive reviews | 33.3% of reviews | **100.0% of reviews** |
| In-app purchases | No | No |
| Ads | Yes | **No** |
| Update frequency | Every 14 months | **Every 5 months** |
| Monetization | Paid | **Free** |
| Size | 10 MB | 13 MB |
| Requires iOS | 15.0 | 15 |
| Devices | **iPhone, iPad, iPod** | iPhone, iPod |
| Age rating | 4+ | 4+ |
| Developer | [Pro Certs Software Ltd](https://appshunter.io/developer/444429696) | [Locken Services](https://appshunter.io/developer/722287762) |

## What reviewers say

### Fault Current Calculator (PFC)

[App page](https://appshunter.io/ios/app/fault-current-calculator-pfc/id577611194)

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:** macOS Compatibility, Vision Pro support

**In-app purchases:** none


### Cornerstone.Network MyLocken

[App page](https://appshunter.io/ios/app/cornerstonenetwork-mylocken/id1634170640)

Manage site access and work details with this app. Book access, view site information, and report issues. It also allows for key synchronization and updates.

**Highlights:** Raise Notification of Work (NOW), Book site access, View site access information, Report site issues, Sync and update keys

**Features:** macOS Compatibility, Vision Pro support

**In-app purchases:** none


## Frequently asked questions

### Is Fault Current Calculator (PFC) free?

Fault Current Calculator (PFC) is free to download, with no in-app purchases.

### Is Cornerstone.Network MyLocken free?

Cornerstone.Network MyLocken is free to download, with no in-app purchases.

### Do Fault Current Calculator (PFC) or Cornerstone.Network MyLocken have ads?

Fault Current Calculator (PFC) shows ads; Cornerstone.Network MyLocken does not.

### Which is updated more often, Fault Current Calculator (PFC) or Cornerstone.Network MyLocken?

Fault Current Calculator (PFC) ships an update every 14 months, and Cornerstone.Network MyLocken every 5 months. Most recently, Fault Current Calculator (PFC) was updated on October 24, 2026 and Cornerstone.Network MyLocken on October 30, 2026.

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*Compared by [AppsHunter](https://appshunter.io/) from daily US App Store data. Review summaries are generated from verbatim App Store reviews.*