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Topic: 110/220

User: Little Bill, Location: Tennessee NEC:2017

Asked on: Sunday, June 8, 2025 at 7:26 pm EDT
Answered on: Sunday, June 8, 2025 at 7:42 pm EDT

Question: I was politely trying to correct someone on the proper nominal voltage we use today. Telling him that it is 120/240. The person lives in Michigan and he said in his area, they still have 110/220.Can anyone confirm this?

No, the person is likely mistaken, or perhaps referring to old/outdated equipment. The standard nominal voltage in the US, including Michigan, is 120/240 volts.Here's a breakdown: Nominal vs. Actual

It's important to distinguish between "nominal" and "actual" voltage. "Nominal" is the stated, ideal voltage. The "actual" voltage you measure can fluctuate slightly depending on load and other factors.


120/240V is the Standard

While older systems might have been designed around 110/220V, that's not the current standard. The move to 120/240V was gradual, but it's been the established standard for many years. This voltage is compatible with older equipment, so there was no need for a complete overhaul when the standard changed.

Why the Shift?
The increase to 120/240V allows for more efficient power transmission and distribution. It reduces losses in the system. What They Might Be Seeing



Old Equipment

The person might be looking at nameplates on very old appliances or equipment that still state 110V or 115V. These appliances will still function properly on the 120V service.


Voltage Drop

If their wiring is old or inadequate, they might be experiencing a significant voltage drop, which causes the voltage at their outlets to be lower than 120V under load. They might mistakenly assume this lower reading is the "normal" voltage.

Misunderstanding

They might simply be misinformed about the actual nominal voltage.

Therefore, while they might be
experiencing voltages closer to 110/220V due to voltage drop or looking at older equipment ratings, the nominal* voltage supplied to homes in Michigan (and throughout the US) is 120/240V.


To politely correct them, you could say something like:"While older equipment might have been rated for 110/220V, the current standard nominal voltage in the US, including Michigan, is 120/240V. You might be seeing lower voltages at your outlets due to voltage drop, but the power company is supplying 120/240V." Flag for review

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