dishwashers

Status
Not open for further replies.
dhducati said:
I'm wondering where 422.31(B) would apply to an HP-rated appliance in that case. I guess I'm wondering what type of appliance might be "rated over 1/8 hp" (422.31(B)) and not be a "motor driven appliance of more than 1/8 hp" (422.32).

Perhaps I'm confused by the wording. I can see that a dishwasher with a pump motor < 1/8 hp would fall into 422.31(B) (because the heater would take it over 300VA) but not 422.32.

Dave
Click to expand...


I dont see in 422.32 where just the motor has to be more than 1/8, but the motor-driven appliance...


[Edit] I think I may have misread your post.
 
Last edited:
dhducati said:
Perhaps I'm confused by the wording. I can see that a dishwasher with a pump motor < 1/8 hp would fall into 422.31(B) (because the heater would take it over 300VA) but not 422.32.

Dave
Click to expand...

I see your confusion as I'm right there with you. Poorly written code IMO.
 
I bought a switch a few years back that was horse power rated and it didn't have a motor on or in it.

Bought a contactor the other day and it was horse power rated and again I couldn't find the motor.

I installed a boiler a few years back that was rated in horse power that didn't have any motors but then again what do I know.

In basic electricity what are we taught about horse power? Does not one horse power equal 746 watts?
 
jwelectric said:
I bought a switch a few years back that was horse power rated and it didn't have a motor on or in it.

Bought a contactor the other day and it was horse power rated and again I couldn't find the motor.

I installed a boiler a few years back that was rated in horse power that didn't have any motors but then again what do I know.

In basic electricity what are we taught about horse power? Does not one horse power equal 746 watts?
Click to expand...

Yes, horse power is a unit of power. Recent editions of the NEC use SI (metric) units primarily, and HP isn't an SI unit for power. The NEC does use HP extensively in the context of motors. I looked for a definition or explanation of this in the 2005 NEC, and couldn't find one. The closest I got was the definition for "Switch, Motor Circuit" in Art 100: A switch rated in horsepower that is capable of interrupting the maximum operating overload current of a motor of the same horsepower rating as the switch at the rated voltage. I think HP ratings in the NEC are closely tied to the characteristics of motors, not a general measure of electrical power.

Your boiler example, if electric, would answer my question though -- thanks.
 
Status
Not open for further replies.
Top