Quick Hits

EPISODE 4 — CALCULATING THE ALLOWABLE AREA

SLIDE 1 — NOW WE DO MATH

Suppose your raceway has:

1.000 in²

of total internal area.

You have 3+ conductors.

What's your maximum allowable conductor area?

SLIDE 2 — USE THE PERCENTAGE

3+ conductors:

40%

Convert:

40% = 0.40

Now:

1.000 × 0.40

= 0.400 in²

🔥 That's your maximum allowable conductor area.

SLIDE 3 — THE FORMULA

🧮

ALLOWABLE AREA

=

TOTAL INTERNAL AREA × FILL %

Example:

2.000 in² × 0.40

= 0.800 in²

So your conductors must occupy:

≤ 0.800 in²

SLIDE 4 — EXAM QUESTION

Raceway internal area:

1.500 in²

Three or more conductors.

Maximum conductor area?

A️⃣ 0.465 in²

B️⃣ 0.600 in²

C️⃣ 0.750 in²

D️⃣ 0.795 in²

🔥 ANSWER: C

1.500 × 0.40 = 0.600

Wait... 👀

That's B!

🧠 ANSWER: B — 0.600 in²

Don't rush the math.

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