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Forum topic by Sloopmk posted 04-12-2016 02:36 AM 1014 views 0 times favorited 29 replies Add to Favorites Watch
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Sloopmk

39 posts in 259 days


04-12-2016 02:36 AM

Hello All.

I recently got a used bandsaw with a 4.5 Hp, single phase, 220V motor. It has a three prong plug with 14/3 gauge cord. I have an extension cord from my sub panel that is a 10/4 gauge and 4 prong plug,hooked up to a 30 amp breaker (I use for my table saw).

Do I have to run a second extension cord and use 14/3 gauge wire hooked up to a 20 amp breaker? I think that is correct bc I need a 20 amp breaker so it will flip before I burn up the 14/3 gauge wire, but that’s what I’m unsure of.

Thanks in advance for the help.


29 replies so far

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English

517 posts in 942 days


#1 posted 04-12-2016 02:45 AM

14 gauge wire is only rated at 15 amps and if the cord is very long it will have trouble supporting that. A 4.5 hp 22 volt motor is going to need more than 20 amps. So I would run a new cord from the sub panel to the band saw. The gauge of the wire should be determined by the full load amps of the band saw and the length of the cable.. That information should be on the motor data plate.

-- John, Suffolk Virgina

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OrvsR4me

13 posts in 301 days


#2 posted 04-12-2016 03:02 AM

English is correct. Bigger wire and breaker needed. I’d pull 10-3 (or 10-2) and use a 30 Amp breaker for a 4.5hp motor. Check the plate to confirm amperage and wire/breaker +30%.

-- Small minds talk about people. Average minds talk about events. Great minds talk about ideas.

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runswithscissors

2189 posts in 1490 days


#3 posted 04-12-2016 04:17 AM

How many total amps does it draw? 220v machines often have surprisingly light cords. I surmise this is because at 220 volts, the motor is drawing only half the amps that a 110 volt motor would draw.

Also, you needn’t use more that a 2 wire cable (with ground), as there is no neutral needed (certain appliances, like clothes dryers, need 3 wires because the motors operate off 110, so a neutral wire is needed. But I don’t know why they are made that way, as 220 can be used for small motors, and in fact that’s the way it’s done in Europe and Australia).

-- I admit to being an adrenaline junky; fortunately, I'm very easily frightened

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MrUnix

4232 posts in 1664 days


#4 posted 04-12-2016 04:32 AM

Just make a pig-tail adapter for your current extension cord.

Cheers,
Brad

-- Brad in FL - To be old and wise, you must first be young and stupid

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runswithscissors

2189 posts in 1490 days


#5 posted 04-12-2016 07:17 AM

I believe others here have pointed out that the circuit breaker is to protect the house wiring, not whatever is plugged in to it. So I don’t see why you would need to have a 20 amp breaker for a 14-3 cord. Otherwise, you couldn’t plug low amperage stuff into 15 or 20 amp outlets—like portable drills, for example, that only draw 3.5 to 5 amps.

Others with more knowledge can correct me if I’m wrong.

-- I admit to being an adrenaline junky; fortunately, I'm very easily frightened

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rwe2156

2198 posts in 946 days


#6 posted 04-12-2016 11:59 AM

I believe the FLA (full load amperage) is important. My 5HP compressor is something like 22A. I wouldn’t think a bandsaw would be that high. Your extension cord and breaker should handle that, but I noticed the plug is 20A.

You only need 10/3 wire as RWS said there is no neutral in 240V.

You’ll have to change the plug so I would go to a 30A plug.

-- Everything is a prototype thats why its one of a kind!!

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Sloopmk

39 posts in 259 days


#7 posted 04-12-2016 12:00 PM

I checked the motor and the Amps are listed at 18.2. I’ll want to run my dust collector concurrently, which is around 10 amps. There are tons of different wire gauge calculators online, with significant differences in the results. I’m thinking a 10 gauge wire should do the trick. Thoughts?

I assume a 30 amp breaker would be appropriate.

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SawyerRob

33 posts in 303 days


#8 posted 04-12-2016 01:35 PM

First of all, it isn’t that 220v uses less amps, it’s that it pulls the amps through TWO wires instead on one…

A motor that pulls 18.2 amps on 240v is an HONEST 3.5hp motor, and that’s pretty good hp for a shop band saw… I’d switch the wire to #10 and use a 30 amp breaker, then I’d never have to worry about it again…

SR

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KyleW

9 posts in 240 days


#9 posted 04-12-2016 01:44 PM

10 gauge

-- Kyle, Louisiana

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hairy

2384 posts in 2997 days


#10 posted 04-12-2016 01:45 PM


I ll want to run my dust collector concurrently, which is around 10 amps. Thoughts?

- Sloopmk

I don’t think you can run two 220 volt tools on one circuit at the same time.

-- stay thirsty my friends...

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Sloopmk

39 posts in 259 days


#11 posted 04-12-2016 02:08 PM

Why would I not be able to run two tools concurrently on the same circuit? How is it any different than running two tools concurrently on a 120V circuit?

View WhyMe's profile

WhyMe

615 posts in 1026 days


#12 posted 04-12-2016 02:28 PM



I have an extension cord from my sub panel that is a 10/4 gauge and 4 prong plug,hooked up to a 30 amp breaker (I use for my table saw).

Do I have to run a second extension cord and use 14/3 gauge wire hooked up to a 20 amp breaker?
- Sloopmk

These statements are somewhat troubling. I hope you do not have cords wired directly to the subpanel breaker. You need to have independent 240V circuits with outlets for the extension cords to plug into.

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Sloopmk

39 posts in 259 days


#13 posted 04-12-2016 02:40 PM

For a temporary setup, I have a 10 gauge wire hooked directly to the subpanel, through a small junction box to make sure the wire doesn’t pull out from the sub-panel. I will be permanently wiring my shop in the next couple months, putting in conduit to outlet boxes. I just recently installed the subpanel and needed a temporary setup. Previously only had a single 120V outlet on a 15 amp breaker. The breaker would flip if I stared at it too hard.

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WhyMe

615 posts in 1026 days


#14 posted 04-12-2016 02:53 PM

Depending on where you live and what code you are on will determine what size multiple 240V outlets can be on a single circuit. I’m in Virginia and in a residential use you can have multiple outlets on a single circuit if not over 20A. 30A and higher have to be dedicated circuits serving only one outlet.

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bonesbr549

1176 posts in 2532 days


#15 posted 04-12-2016 02:54 PM

I’f my info from reading this is you have a 4.5 hp motor x 745.7 (watts/hp) thats a total of 3356 watts / voltage of 220v = 15.25 Amps.

At a minimum it should have a 20A cord/plug/recepticle/breaker. I’d not go with a mix/mash of stuff when it comes to electricity.

Of course keep the fire insurance up to date as well.

Just my 2cw

-- Sooner or later Liberals run out of other people's money.

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