PEC FAQ

Common PEC Cable Sizing Questions From First-Time Users

The recurring questions that come up the first time someone opens the PEC calculator — answered directly.

A handful of questions come up repeatedly from first-time users of any cable sizing calculator. Here are the ones specific to PEC.

"Why did the calculator recommend a bigger cable than I expected?"

Almost always because voltage drop — not ampacity — turned out to be the limiting factor at your run length. Check which constraint the calculator flagged as governing before assuming an error.

"Do I need to apply the continuous load factor manually?"

No — the calculator applies it internally based on your load type input. Manually pre-multiplying your current before entering it will double-apply the factor and oversize unnecessarily.

"What if my exact cable size isn't available from my supplier?"

Round up to the next available standard size — never down, even if the gap seems small. See the dedicated article on this exact scenario for more detail.

"Why does ambient temperature matter if my installation is indoors?"

"Indoors" doesn't mean "at reference temperature" — an enclosed ceiling space or switchboard cabinet can run well above the table's reference ambient even without direct sun exposure.

Try the PEC Cable Sizing calculator with your own project's numbers.

Engr. Jason Morales — Founder, SolarEnergyPH & OhmWorks

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