Shop wiring

[toml]

Hi. new member here.
first, apologies if this is not the correct forum or just inappropriate question.
When i had my shop wired i had the electrician put in a 220/240 receptacle for where i planned to put my cyclone. The machine I bought says that it needs a 30 amp service (5 hp motor). My outlet is on 2 20 amp breakers. While it seems like it should be ok, I thought I should run it by anyone more knowledgable.
Thanks, Tom

 

[NC_Horn]

You will need to at least upgrade your breakers to 30 amp.

Below is a chart of motors from Electric Motor Basics

[FONT=Arial, Helvetica, Geneva, Swiss, SunSans-Regular]TRUE HP[/FONT]
[FONT=Arial, Helvetica, Geneva, Swiss, SunSans-Regular]AMPS at 115VAC[/FONT]
[FONT=Arial, Helvetica, Geneva, Swiss, SunSans-Regular]AMPS at 230 VAC[/FONT]
[FONT=Arial, Helvetica, Geneva, Swiss, SunSans-Regular]1/4[/FONT]
[FONT=Arial, Helvetica, Geneva, Swiss, SunSans-Regular]3.2 - 2.3[/FONT]
[FONT=Arial, Helvetica, Geneva, Swiss, SunSans-Regular]1.6 -1.2[/FONT]
[FONT=Arial, Helvetica, Geneva, Swiss, SunSans-Regular]1/3[/FONT]
[FONT=Arial, Helvetica, Geneva, Swiss, SunSans-Regular]4.3 - 3.1[/FONT]
[FONT=Arial, Helvetica, Geneva, Swiss, SunSans-Regular]2.2 - 1.5[/FONT]
[FONT=Arial, Helvetica, Geneva, Swiss, SunSans-Regular]1/2[/FONT]
[FONT=Arial, Helvetica, Geneva, Swiss, SunSans-Regular]6.5 - 4.6[/FONT]
[FONT=Arial, Helvetica, Geneva, Swiss, SunSans-Regular]3.2 - 2.3[/FONT]
[FONT=Arial, Helvetica, Geneva, Swiss, SunSans-Regular]3/4[/FONT]
[FONT=Arial, Helvetica, Geneva, Swiss, SunSans-Regular]9.7- 7.0[/FONT]
[FONT=Arial, Helvetica, Geneva, Swiss, SunSans-Regular]4.9 - 3.5[/FONT]
[FONT=Arial, Helvetica, Geneva, Swiss, SunSans-Regular]1[/FONT]
[FONT=Arial, Helvetica, Geneva, Swiss, SunSans-Regular]13.0 - 9.3[/FONT]
[FONT=Arial, Helvetica, Geneva, Swiss, SunSans-Regular]6.5 - 4.6[/FONT]
[FONT=Arial, Helvetica, Geneva, Swiss, SunSans-Regular]1 1/2[/FONT]
[FONT=Arial, Helvetica, Geneva, Swiss, SunSans-Regular]19.5 - 13.9[/FONT]
[FONT=Arial, Helvetica, Geneva, Swiss, SunSans-Regular]9.7 - 7.0[/FONT]
[FONT=Arial, Helvetica, Geneva, Swiss, SunSans-Regular]2[/FONT]
[FONT=Arial, Helvetica, Geneva, Swiss, SunSans-Regular]25.9 - 18.5[/FONT]
[FONT=Arial, Helvetica, Geneva, Swiss, SunSans-Regular]13.0 - 9.3[/FONT]
[FONT=Arial, Helvetica, Geneva, Swiss, SunSans-Regular]5[/FONT]
[FONT=Arial, Helvetica, Geneva, Swiss, SunSans-Regular]64.9 - 46.3[/FONT]
[FONT=Arial, Helvetica, Geneva, Swiss, SunSans-Regular]32.4 - 23.2[/FONT]​

From this, a 5 HP - 70% eff will draw 23.2 amps - startup current will be higher.

 

[NC_Horn]

Well, the chart didn't make it into the post - take a look at the website and you will see what I was saying.

 

[Mike Camp]

If you decide to upgrade the breakers make sure the receptacle is rated for 30A and the wire needs to be 10 gauge (for most runs) for a 30A service. At that point though you might as well get another circuit run.

 

[Bryan S]

Tom the 20 amp service is not enough for that motor, a 5 hp motor is going to pull around 22 or 23 amps. At a minimum you do need to upgrade to a 30 amp circuit and outlet, and pull #10 wire to the plug. Better would be 40 amp breaker with #8 wire, you will not go wrong going that high, but may not need quite that much.

The basic guide line for sizing a circuit is that you want no more than 80% load on the circuit. You have a 20 amp circuit, multiply that times .8 and you get 16 amps. I know that a 5 hp motor draws way more than that. 80% of a 30 amp circuit is 24, look at the name plate on the motor if it is at or less that 24 amps you should be ok with a 30 amp circuit. Make sure your wiring, outlets and plugs have at least as high a amp rating as your breaker.

 

[scsmith42]

tom the 20 amp service is not enough for that motor, a 5 hp motor is going to pull around 22 or 23 amps. At a minimum you do need to upgrade to a 30 amp circuit and outlet, and pull #10 wire to the plug. Better would be 40 amp breaker with #8 wire, you will not go wrong going that high, but may not need quite that much.

The basic guide line for sizing a circuit is that you want no more than 80% load on the circuit. You have a 20 amp circuit, multiply that times .8 and you get 16 amps. I know that a 5 hp motor draws way more than that. 80% of a 30 amp circuit is 24, look at the name plate on the motor if it is at or less that 24 amps you should be ok with a 30 amp circuit. Make sure your wiring, outlets and plugs have at least as high a amp rating as your breaker.

+100.

 

[toml]

You will need to at least upgrade your breakers to 30 amp.

Below is a chart of motors from Electric Motor Basics

[FONT=Arial, Helvetica, Geneva, Swiss, SunSans-Regular]TRUE HP[/FONT]
[FONT=Arial, Helvetica, Geneva, Swiss, SunSans-Regular]AMPS at 115VAC[/FONT]
[FONT=Arial, Helvetica, Geneva, Swiss, SunSans-Regular]AMPS at 230 VAC[/FONT]
[FONT=Arial, Helvetica, Geneva, Swiss, SunSans-Regular]1/4[/FONT]
[FONT=Arial, Helvetica, Geneva, Swiss, SunSans-Regular]3.2 - 2.3[/FONT]
[FONT=Arial, Helvetica, Geneva, Swiss, SunSans-Regular]1.6 -1.2[/FONT]
[FONT=Arial, Helvetica, Geneva, Swiss, SunSans-Regular]1/3[/FONT]
[FONT=Arial, Helvetica, Geneva, Swiss, SunSans-Regular]4.3 - 3.1[/FONT]
[FONT=Arial, Helvetica, Geneva, Swiss, SunSans-Regular]2.2 - 1.5[/FONT]
[FONT=Arial, Helvetica, Geneva, Swiss, SunSans-Regular]1/2[/FONT]
[FONT=Arial, Helvetica, Geneva, Swiss, SunSans-Regular]6.5 - 4.6[/FONT]
[FONT=Arial, Helvetica, Geneva, Swiss, SunSans-Regular]3.2 - 2.3[/FONT]
[FONT=Arial, Helvetica, Geneva, Swiss, SunSans-Regular]3/4[/FONT]
[FONT=Arial, Helvetica, Geneva, Swiss, SunSans-Regular]9.7- 7.0[/FONT]
[FONT=Arial, Helvetica, Geneva, Swiss, SunSans-Regular]4.9 - 3.5[/FONT]
[FONT=Arial, Helvetica, Geneva, Swiss, SunSans-Regular]1[/FONT]
[FONT=Arial, Helvetica, Geneva, Swiss, SunSans-Regular]13.0 - 9.3[/FONT]
[FONT=Arial, Helvetica, Geneva, Swiss, SunSans-Regular]6.5 - 4.6[/FONT]
[FONT=Arial, Helvetica, Geneva, Swiss, SunSans-Regular]1 1/2[/FONT]
[FONT=Arial, Helvetica, Geneva, Swiss, SunSans-Regular]19.5 - 13.9[/FONT]
[FONT=Arial, Helvetica, Geneva, Swiss, SunSans-Regular]9.7 - 7.0[/FONT]
[FONT=Arial, Helvetica, Geneva, Swiss, SunSans-Regular]2[/FONT]
[FONT=Arial, Helvetica, Geneva, Swiss, SunSans-Regular]25.9 - 18.5[/FONT]
[FONT=Arial, Helvetica, Geneva, Swiss, SunSans-Regular]13.0 - 9.3[/FONT]
[FONT=Arial, Helvetica, Geneva, Swiss, SunSans-Regular]5[/FONT]
[FONT=Arial, Helvetica, Geneva, Swiss, SunSans-Regular]64.9 - 46.3[/FONT]
[FONT=Arial, Helvetica, Geneva, Swiss, SunSans-Regular]32.4 - 23.2[/FONT]​

From this, a 5 HP - 70% eff will draw 23.2 amps - startup current will be higher.

thank you. chart came across fine.
little disappointing though. I was of course hoping that since i had 2 breakers which were each 20 amps that could manage the load.
I hope that I can just swap out breakers, the #2- 20amp breakers for #2 -- 30 amps breakers.
Thanks again.

 

[Alan in Little Washington]

I hope that I can just swap out breakers, the #2- 20amp breakers for #2 -- 30 amps breakers.
Thanks again.

Please don't do that or think about it that way- the breakers are sized to protect the wiring, their selection is not based on the equipment rating. If you swap out the breakers without verifying you have the appropriate wire size, you risk starting a fire! First, check the gauge of the wire at the panel or outlet. If it is smaller than 10 gauge, you will need to run new wiring to the outlet for that machine before you can change the dual breaker to 30 Amps.

 

[toml]

If you decide to upgrade the breakers make sure the receptacle is rated for 30A and the wire needs to be 10 gauge (for most runs) for a 30A service. At that point though you might as well get another circuit run.

good point. thanks. the cyclone comes with

240v - 3 wire receptacle rated for 30 amp
2 mulberry junction boxes with stainless covers

so i hope I can get away with just swapping the 2 - 20 amp breakers with 2 -30 amp breakers

thanks again

 

[toml]

Please don't do that or think about it that way- the breakers are sized to protect the wiring, their selection is not based on the equipment rating. If you swap out the breakers without verifying you have the appropriate wire size, you risk starting a fire! First, check the gauge of the wire at the panel or outlet. If it is smaller than 10 gauge, you will need to run new wiring to the outlet for that machine before you can change the dual breaker to 30 Amps.

bummer. it is 12/2 (yellow) wire.
on a bright note it will be positioned in the crawl space just behind the the new substation. I am hoping that maybe when I swap out the breakers I'll just swap out the wire as well.
this whole dust control issue has turned to be much more of a headache than i expected.
thank again.

 

[toml]

Tom the 20 amp service is not enough for that motor, a 5 hp motor is going to pull around 22 or 23 amps. At a minimum you do need to upgrade to a 30 amp circuit and outlet, and pull #10 wire to the plug. Better would be 40 amp breaker with #8 wire, you will not go wrong going that high, but may not need quite that much.

The basic guide line for sizing a circuit is that you want no more than 80% load on the circuit. You have a 20 amp circuit, multiply that times .8 and you get 16 amps. I know that a 5 hp motor draws way more than that. 80% of a 30 amp circuit is 24, look at the name plate on the motor if it is at or less that 24 amps you should be ok with a 30 amp circuit. Make sure your wiring, outlets and plugs have at least as high a amp rating as your breaker.

#8 wire with 40 amp breakers?
Why not, right? in for a dime in for a dollar and as long as I am there.
Thank you for the reply.