Cable Calculator

About Cable Calculator Android App

This application calculates the required cable size based on your entered design data and selected options.

Calculate the minimum required cable size in mm² for various cable types & sizes, protective devices, installation methods and correction factors based on BS 7671 IET Wiring Regulations.

You can use this cable calc app to check existing cables and circuits for compliance to verify cable sizes in existing electrical installations or for designing new final circuits and sub main supplies in new installations and create and save PDF file of the calcultion results.

Features:
✔ Print cable calculation results
✔ Verification and validation checks
✔ Support for manufacturer specific MCCB's & ACB's (max Zs)
✔ Support for RCD's in TT Earthing Systems

Design Parameters:
- Ib : Design current (Amps)
- L : Circuit length (Meters)
- Vd : Maximum permitted volt drop (%)
- Uo : Supply voltage (Volts)
- Ze/Zdb : Supply source earth loop impedance (Ohms)
- In : Protective device rating (Amps)
- s : Maximum disconnection time (Seconds)
- Cable type
- Installation method
- Protective device type
- Earthing system type (TN-C-S, TN-S, TT)

Correction Factors:
- Cg : Grouping
- Ca : Ambient air temperature
- Ca : Ambient ground temperature
- Ci : Thermal insulation
- Cc : BS 3036 semi-enclosed fuses

Cable Calculator Calculations:
- It : Tabulated current
- R1+R2 : Circuit expected R1+R2 value
- Zs : Circuit expected Zs value
- Max Zs : Calculated max Zs values for 0.2s, 0.4s & 5s (80% + 100% values)
- Vd : Calculated voltage drop %
- CF : Total applied correction factor value
- Minimum required cable size (mm²)

This cable calculator takes into account and applies the following factors for it's cable sizing calculations:
- Vd : Max volt drop
- Cf : Correction factors
- L : Length of circuit
- Zs : Maximum Zs 80% temperature adjusted value

Example Verification Checks:
- Checks the calculated Zs with the Max Zs 80% value
- Checks if user selects TT earthing system = RCD required
- Checks if user selects 3% volt drop (lighting) and device In = >16 amps
- Checks if user selects disconnection time 5 seconds and device In = <32 amps
- Checks if selected protective device Max Zs already exceeds your supply Zs/Zdb value
- Checks if design current (Ib) exceeds the protective device rating (In)
- Checks if the protective device rating (In) is double the design current (Ib)
- + many more...

A great cable sizing tool which also calculates the expected Zs value, volt drop %, and estimated r1+r2 in addition to the minimum required cable size.

How to use:
1) STEP 1 - Enter your cable calculation design parameters
2) STEP 2 - Select an installation method & apply any relevant correction factors
3) Tap "Calculate" to calculate the cable size
4) Tap the printer icon to Print cable calculation results
5) Optional, sign the screen to sign the document

This cable size calculator app is designed for Android phones, tablets and Android based PCs.

Check out our full collection of electrical apps & software packages for electricians https://www.procertssoftware.com/apps/