⚡ Code Corner:🔸 NEC 225.37 – Identification of Disconnecting Means

📖 What NEC 225.37 says:

👷 What It Means on the Job:

When you run a feeder to a separate building or structure, the disconnect (usually an outdoor panel or disconnect switch) must be:

• Clearly labeled to show what it shuts off

• Legible and permanent

• Not just a Sharpie on a panel door!

🧰 Field Example:

You’re installing a 200A disconnect on the exterior wall of a detached shop. You must label it something like:

If there’s more than one feeder to the same building? Each disconnect must be separately labeled — don’t just call both “Shop.”

🚩Common Mistakes:

• Leaving it blank (“I’ll do it later…”)

• Writing with a marker that fades in the sun

• Using abbreviations no one understands (“W.B. SWD PNL” 😵)

✅ Pro Tip:

Use engraved placards or UV-stable labels with:

• Panel name

• Voltage

• Building/structure served

• Feeder # if there’s more than one

🔦 Why It Matters:

• Saves time in emergencies

• Helps inspectors

• Complies with 225.37

• Avoids red tags and costly rework

❓ Quick Code Quiz

Choose the correct answer:

Question:
You install a 200A disconnect for a feeder supplying a detached storage unit. Which of the following is required by NEC 225.37?

A) The disconnect must be locked
B) The disconnect must be painted red
C) The disconnect must be labeled to show which building it serves
D) The disconnect must be fire-rated

🧠 Think it through:
This Code section is all about identification, not physical protection or color. While locking or painting might be helpful, they aren’t required. The only mandatory step? Making sure anyone looking at the disconnect knows exactly what it controls.

✅ Answer:

📘 Reference:
NEC 225.37 – Identification of Disconnecting Means

This avoids confusion during emergencies, service work, or inspections — and keeps your install compliant from day one.