Exhaust blower switch
- Thread starter PowerdT
- Start date
- Status
- Location
- Bremerton, Washington
- Occupation
- Master Electrician
use the wall switch to control a motor starter, so you also have overloads
Even though the blower had means of disconnect. Is it still good to use wall switch to control motor starter?
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hbiss
EC, Westchester, New York NEC: 2014
- Location
- Hawthorne, New York NEC: 2014
- Occupation
- EC
I want the switch to be inside mechanical/lab room.
How do I want to turn on/off- toggle switch
- Location
- Bremerton, Washington
- Occupation
- Master Electrician
The wall switch will be a remote control for the starter. You need to determine if there is a power outage should the fan turn on when power is restored. If you don’t want the fan to automatically restart, then you will need to use a start stop push button, so when power drops out, start button is pushed to restart.
if you use a single pole wall switch, I would use a lighted switch, light on, fan on
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I want the fan to be on when/if power is restored I case of outage so I want to use switch. Question is the fan is 3 phase, how is single pole work? Isn’t it supposed to be 3 Pole wall switch
Shaneyj
Senior Member
- Location
- Katy, Texas
- Occupation
- Project Engineer
Here's a 3 pole switch meant for motors. A few bucks more than a light switch but not much.
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- Location
- Bremerton, Washington
- Occupation
- Master Electrician
The switch will work, but you will need to provide overload protection for the motor and a disconnect within sight of the motor. If the switch is considered the controller you will need a disconnect for it.
suggest you review section 430.102
suggest you review section 430.102
Thank you.Here's a 3 pole switch meant for motors. A few bucks more than a light switch but not much.
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Basically what I have from my understanding 430.102.
Panel board (208v, 20A, 3PH) breaker ——> toggle switch—-> disconnecting Means ——> exhaust fan motor
the disconnect means and motor are in sight.
article is tricky somehow it is also telling me I need disconnect switch for the controller(toggle switch)
hbiss
EC, Westchester, New York NEC: 2014
- Location
- Hawthorne, New York NEC: 2014
- Occupation
- EC
No, you can't use that.
3 phase motors have no overload protection so you have to provide a motor starter that will provide overload protection. The starter has a contactor that you can control with a single pole toggle switch to turn the fan on and off. You will also need to supply a disconnect switch in most instances between the panel and starter.
-Hal
petersonra
Senior Member
- Location
- Northern illinois
- Occupation
- Semi-retired engineer
I think there are some small 3 phase motors that have built in overload protection.
Given the original parameters, I doubt that’s the case here. At least a 5 HP motor.
petersonra
Senior Member
- Location
- Northern illinois
- Occupation
- Semi-retired engineer
could use a manual motor starter that would fit in a handy box and sort of looks like a light switch
Yes there are motor starter built in with overload protection
hbiss
EC, Westchester, New York NEC: 2014
- Location
- Hawthorne, New York NEC: 2014
- Occupation
- EC
That's usually the way it is. The toggle switch is just used to turn the fan on and off and usually located in the area it serves. It's not a safety disconnect. The toggle is just a simple single pole switch wired with a couple of #12s back to the controller. Makes it easy, rather than running all three phases back and forth.
Is this a kitchen exhaust fan?
If the motor has an internal overload no starter is required. You would still need a disconnect within sight of the motor.
-Hal
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