35mm 5 Core SWA Current Carrying Capacity Calculator

Current Carrying Capacity Calculation:

\[ I = 115 A \text{ (buried underground for 35mm² 5-core XLPE SWA per standards)} \]

Installation Method:

Ambient Temperature:

°C

Cable Grouping:

Current Carrying Capacity (I):

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1. What Is Current Carrying Capacity?

Current carrying capacity refers to the maximum electric current a cable can carry continuously without exceeding its temperature rating. For 35mm² 5-core SWA (Steel Wire Armored) cable, this is typically 115A when buried underground at 30°C ambient temperature according to standard specifications.

2. How The Calculator Works

The calculator uses the base current rating and applies correction factors:

\[ I = I_{\text{base}} \times F_{\text{temp}} \times F_{\text{group}} \times F_{\text{install}} \]

Where:

\( I_{\text{base}} \) — Base current rating (115A for buried 35mm² 5-core SWA)
\( F_{\text{temp}} \) — Temperature correction factor
\( F_{\text{group}} \) — Cable grouping correction factor
\( F_{\text{install}} \) — Installation method correction factor

Explanation: Different installation conditions affect the cable's ability to dissipate heat, requiring adjustment of the base current rating.

3. Importance Of Proper Cable Sizing

Details: Correct current carrying capacity calculation ensures electrical safety, prevents overheating, maintains system efficiency, and complies with electrical regulations and standards.

4. Using The Calculator

Tips: Select the installation method, enter ambient temperature, and specify if multiple cables are grouped together. The calculator will apply appropriate correction factors to determine the safe current carrying capacity.

5. Frequently Asked Questions (FAQ)

Q1: Why does temperature affect current rating?
A: Higher temperatures reduce a cable's ability to dissipate heat, requiring derating to prevent insulation damage and potential fire hazards.

Q2: What is SWA cable typically used for?
A: Steel Wire Armored cable is used for mains electricity supply, underground systems, industrial applications, and anywhere mechanical protection is required.

Q3: How does cable grouping affect capacity?
A: Grouped cables have reduced heat dissipation capability, requiring derating to prevent mutual heating effects.

Q4: Are there different standards for current rating?
A: Yes, different countries and regions may have slightly different standards (IEC, BS, NEC, etc.) which can affect current ratings.

Q5: When should professional advice be sought?
A: Always consult a qualified electrical engineer for critical applications, complex installations, or when regulatory compliance is required.