GlennG
Member
- Location
- Hicksville, NY
I have a 1/2hp rooftop vent fan, does that require a starter? If im not mistaken isnt 1/2hp the cutoff for needing one? Thanks.
Commercial rooftop fan
- Thread starter GlennG
- Start date
- Status
- Location
- Logan, Utah
Check out 430.83 for the ratings of motor controllers.
430.83(C) deals with stationary motors 2 HP and less.
Chris
430.83(C) deals with stationary motors 2 HP and less.
Chris
eric9822
Senior Member
- Location
- Camarillo, CA
- Occupation
- Electrical and Instrumentation Tech
Take a look at 430.83(C). You still need to consider overload protection.
I just knew I should have refreshed the page before replying.
I just knew I should have refreshed the page before replying.
Last edited:
- Location
- San Francisco Bay Area, CA, USA
- Occupation
- Electrical Engineer
430.83 has to do with a "controller". A "starter" is a controller + overload protection.
There is no official "cutoff" size for when a starter is required. If the motor SPECIFICALLY SAYS it has internal thermal protection, then a controller, per 430.83, will suffice.
If the motor does NOT SPECIFICALLY say that it has internal thermal protection, then you MUST provide running thermal overload protection externally, which combined with the controller rules in 430.83, means a starter.
A starter can be a Manual Motor Starter (MMS) or an electromechanical magnetic motor starter (Mag. Starter), or any type of electronic controller that is suitable listed as a starter, i.e. a VFD, soft starter, etc.
There is no official "cutoff" size for when a starter is required. If the motor SPECIFICALLY SAYS it has internal thermal protection, then a controller, per 430.83, will suffice.
If the motor does NOT SPECIFICALLY say that it has internal thermal protection, then you MUST provide running thermal overload protection externally, which combined with the controller rules in 430.83, means a starter.
A starter can be a Manual Motor Starter (MMS) or an electromechanical magnetic motor starter (Mag. Starter), or any type of electronic controller that is suitable listed as a starter, i.e. a VFD, soft starter, etc.
GlennG
Member
- Location
- Hicksville, NY
Thanks for the info.
renosteinke
Senior Member
- Location
- NE Arkansas
This thread caused me a real deja-vu moment.
Screw the code. Use a starter- preferably one with electronic overloads.
Why? Because it a) makes it easier to add controls and b) will protect the motor from low voltage, phase lose, etc.
With the condition of our grid, you can't trust the PoCo to give you full power at lunchtime on a hot summer day.
If you do need to replace the motor, forget the usual sources (Graybar, Motion, etc.) They'll look at that motor, call their factory contact, and tell you it's a strange OEM that's not available. The one they want to sell you will have a peckerhead that won't fit in the fan, rather than the terminal box on the end bell.
Instead, visit your local motor shop. Chances are he has a new one sitting right under the counter.
Screw the code. Use a starter- preferably one with electronic overloads.
Why? Because it a) makes it easier to add controls and b) will protect the motor from low voltage, phase lose, etc.
With the condition of our grid, you can't trust the PoCo to give you full power at lunchtime on a hot summer day.
If you do need to replace the motor, forget the usual sources (Graybar, Motion, etc.) They'll look at that motor, call their factory contact, and tell you it's a strange OEM that's not available. The one they want to sell you will have a peckerhead that won't fit in the fan, rather than the terminal box on the end bell.
Instead, visit your local motor shop. Chances are he has a new one sitting right under the counter.
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