I am having discussions about mounting a panel horizontally. Article 240.81 states that "where circuit breaker handles are operated vertically rather than horizontally, the "up" position of the handle shall be the "on" position. So..... if it's a main breaker panel and it's mounted so that the main breaker is on the right side wouldn't the breakers on the top row, odd numbers, have to have a special type of breaker? Because when you flip them on the handle would be facing down and when you turned them off the handle would be in the up position. The breakers on the bottom row would be fine because on the breaker handle would be in the up position. This is what I feel the article says. Does anyone have any idea why this is a code? I heard many years ago that if a breaker on the top was turned off that gravity could turn it back on. Does anyone know the actual reasoning behind this?
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Panels mounted horizontally
- Thread starter frani
- Start date
I always thought it was the switching convention that up is on, down is off that drove this. Most panels I see can't be mounted 90 degrees from their designed mounting direction. A panel with a single column of breakers could have some horizontal choices, but you'd want the door swing to work in your favor too along with breakers being up when on.
ModbusMan
Senior Member
- Location
- Cleveland, OH
- Occupation
- Building Automation Engineer
My impression as well... just having two-way switches at opposite ends of the stairwell is annoying enough when one switch is opposite and you're fumbling around at 1am seeking that mint choco chip ice cream hit.I always thought it was the switching convention that up is on, down is off that drove this.
Thank you for your reply. I know that I heard many many years ago that it was because of gravity but that's all I knew. Thanks again!It's an old rule that dates back to knife switches. You didn't want the switch to accidentally close due to gravity. It's silly to keep it and the Canadians wisely did away with it.