TS Amps?

[Dave Cohen]

Got my "new" used JET Cabinet 3HP single phase (708661PK) saw home, the manual does not indicate the AMPs for the elecrtical circuit in the Specs.

I called customer service at JET and they said to put it on a 30AMP circuit, the motor label says 14.5 amps, does this all JIBE?

[SCOTT ANDREWS]

My Grizzly 1023 says the motor is 18 amps.I think they give you the max. amperage the motor pulls.Grizzly recommended a 20 amp breaker.I installed a 20 amp breaker with #10 wire and have never came close to blowing the breaker.Some people insist on running a bigger breaker than recommended.I would go with a 20 amp and #10 wire if it were me.Just my opinion and experience with my saw.

[Dave Cohen]

Is there some reason to use 10 gauge wire for 20AMP with 240V?

I know for 20AMP 120V, 12 gauge is sufficient.

[Rod Sheridan]

Hi Dave, if the saw motor is less than 16 amperes (which yours is), install a 20 ampere breaker with #12 AWG wire.

The only reason to go with #10 AWG wire is if your circuit length is abnormally long.

Regards, Rod.

P.S. Remember to put a NEMA 6-20R receptacle in for your saw.

[Dave Cohen]

Thanks Rod for the very precise and useful reply:)

[Tom Veatch]

Got my "new" used JET Cabinet 3HP single phase (708661PK) saw home, the manual does not indicate the AMPs for the elecrtical circuit in the Specs.

I called customer service at JET and they said to put it on a 30AMP circuit, the motor label says 14.5 amps, does this all JIBE?

I assume you are going to run it off a 220-240V circuit. If you are going to have to add a circuit for the saw, a 10ga 30A circuit is OK but is overkill. I wouldn't consider running 10ga wire for a 30A circuit unless I was fairly sure I'd be needing it for a 5HP motor at some point in the future.The saw will run perfectly well on a 12ga 20A circuit.

You may hear such things as needing a big breaker because of high current at motor start up. That might have been the case in the days of quick blowing fuses or for motors that have to start under load but your saw's motor is not loaded at startup.

A "Standard" 20A circuit breaker will permit more than enough overcurrent for more than enough time to start your saw's motor. My 3HP Jet has been plugged into a 20A circuit for more than 5 years now and the breaker has never tripped.

[glenn bradley]

A DC manufacturer I was talking with has a 3HP unit that draws 18amps. they too recommend a 30amp breaker. A user on their blog has run a 20amp breaker on 10ga wire for a couple years without incident. I would tend to go with the manufacturer's recommendation just so it isn't an issue. Unless your buying wire by the 250' spool, 12 to 10ga cost difference isn't significant enough to bother me although 12ga is generally fine. I just don't want to ever have to re-wire a given run because I took the lesser of two recommendations. That's just me.

[Rod Sheridan]

Glenn, that's because an 18 ampere load is too large for a 20 ampere circuit.

A 14 ampere load is just fine for a 20 ampere circuit.....Rod.

[Larry Fox]

Bizzare and unnecessary as it may seem, if the saw is still under waranty you might want to call a second time for verification and do as they say. You don't want them to have "wiggle-room" if you need to make a claim as you will likley loose the "wiggling" match if it comes to that. I had Ingersol Rand tell me that they would not honor a warranty if I had a plug on my compressor instead of having it hard-wired. It is hard-wired. :(

[Ken Fitzgerald]

The breaker in your box should be sized to the gauge wire you are using. For example if your machine requires 24 amps...you'd better be using #10 gauge and you could use a 30 amp breaker. If your wire is #12 gauge you can use a 20 amp breaker .......The breaker is sized to the feed wire size not the motor.......Hopefully you have wire size and breaker size has a capacity larger than the motor you are using..........

[Dave Cohen]

thanks its not under warranty, its a used saw that I just bought...just want to do what safe and code for my family and the motor.

[Steven Wilson]

FLA is 14.5A. Just use 12GA wire and a 20A breaker and you will be following code.

[John Economou]

Hi Dave, if the saw motor is less than 16 amperes (which yours is), install a 20 ampere breaker with #12 AWG wire.

The only reason to go with #10 AWG wire is if your circuit length is abnormally long.

Regards, Rod.

P.S. Remember to put a NEMA 6-20R receptacle in for your saw.

This is a little off the subject but I just ran a new circuit for my TS and did not use the plug or receptacle you mentioned. I used a twistlock plug and receptacle rated at 20A 220V. Is there any problem using twistlock instead of a NEMA 6-20R?

[David G Baker]

My pole barn is 30'X40', my breaker box is located near the front of the building and my compressor (don't remember the starting amps) is located at the other side of the building also near the front. The wire length running around the wall is approximately 110 feet so I use #10 wire to compensate for any potential loss due to the long cable run. If it was a shorter run I would have used #12 wire. The breaker is 20amps.
I would have saved some money on the wire if I could have run the wire overhead.

[Brandon Shew]

The only reason to go with #10 AWG wire is if your circuit length is abnormally long.


That's not the "only" reason.

If you think that you may go w/ a larger appliance at a later date, you can just upgrade the breaker since you already ran the #10 wire. I ran #10 in my shop to both 220 outlets even though I only have a 15 AMP breaker on one and a 20 AMP breaker on the other. Once the sheetrock is on the walls, it makes it a lot harder to run a new wire.

[Rick Christopherson]

Dave,
You received more accurate information in your posting on another forum than you did in this thread, hence my reply to this discussion. I did not respond in the other forum because the pieces of misinformation were already corrected by other posters.

In complete accordance with the National Electric Code (NEC) your 14.5 amp tablesaw can technically be connected to a 15 amp, 240 volt circuit with #14 wire (14/2 romex for example). However, I personally would not recommend using a 15 amp circuit, and I don’t think anyone here would disagree. The most appropriate choice for wiring your tablesaw is a 20-amp circuit with #12 wire (2-hots, 1-gound, zero-neutral) and either a NEMA 6-20 outlet, or a NEMA L6-20 twist lock outlet.

Because this is a dedicated circuit with only a single outlet, you must use a 20-amp receptacle, but this will still permit a 15-amp tool plug to be plugged in (see the picture of the NEMA 6-20 receptacle on the other forum). You may also use the NEMA L6-20 twist lock, but this will not accept a 15 amp plug like the straight-blade will.
I called customer service at JET and they said to put it on a 30AMP circuit, the motor label says 14.5 amps...There is no interpretation of the NEC that would prescribe this as a requirement. This is a statement that some people, including customer support, will make when they do not understand electrical wiring. Also, depending on the circumstances and configuration of their tool, this may even lead to a code violation, so these manufacturers are ill-advised to be stating this blindly as they do.
Glenn, that's because an 18 ampere load is too large for a 20 ampere circuit.

A 14 ampere load is just fine for a 20 ampere circuit.....Rod.Both Glenn and Rod have mistakenly underrated the capability of this type of circuit. Your tablesaw is not a continuous load on a cord and plug connection. It is not required to derate the circuit. As I already stated, your 14.5 amp motor could technically be installed on a 15-amp circuit if you wished, and an 18-amp saw motor could be installed on a 20-amp circuit. (It could be argued that a dust collector constitutes a continuous load, and this would require derating by 80%, but this is not likely in a home workshop.)

[Dave MacArthur]

As usual, I completely concur with Rick. Without knowledge of your wiring, the manufacturers likely default to the most conservative answer possible that folks will accept without laughing, and say "30 Amps". I'd probably do the same... I expect that for every 20 guys calling, ONE of them probably is going to run 800 feet of 12 ga wire, and drive his dust collector concurrent with the saw, and not tell anyone those details, then call complaining the 20A breaker is tripping. After a month of those folks, were I in charge of answering this question, I would start saying "use 30 A"...
;)

[Dick Bringhurst]

I've had my Jet 3hp on a 20 AMP 240V circuit for years and have had no problems at all. Dick B.

[Eddie Darby]

I run my Jet saw on the same 20 Amp circuit as the Clothes Drier, I just don't run the two at the same time, so no trips.

[Rod Sheridan]

Dave,


Both Glenn and Rod have mistakenly underrated the capability of this type of circuit. Your tablesaw is not a continuous load on a cord and plug connection. It is not required to derate the circuit. As I already stated, your 14.5 amp motor could technically be installed on a 15-amp circuit if you wished, and an 18-amp saw motor could be installed on a 20-amp circuit. (It could be argued that a dust collector constitutes a continuous load, and this would require derating by 80%, but this is not likely in a home workshop.)


Hi, Rick is correct if he knows that your duty cycle will be low enough to not require the 80% rule.

I agree with Rick, however it's based upon an assumption, which I am hesitant to use as I haven't visited the shop or talked to the operator of the saw. Providing advice based upon un-investigated assumptions doesn't constitute due diligence in my book.

A 20 ampere feeder will meet code requirements for all possible operating conditions of the saw, while a 15 ampere feeder would not.

regards, Rod.

[Rick Christopherson]

Hi, Rick is correct if he knows that your duty cycle will be low enough to not require the 80% rule.For the majority of woodworking equipment, it isn't just a matter of duty cycle, but loading cycle as well. It is just as important to understand the purpose behind a code section as it is to understand the wording.

Even in a production wood shop, where a cabinet style tablesaw may have a high duty cycle, it will not have a very high load cycle. A tablesaw, by its nature, spends the majority of its life operating at idle, with spurts of moderate load, and even shorter spurts of full load. So even if a saw was left running all day long, the majority of this time, the motor would be drawing idle-current, which is only 50% of FLA. The exception to this would be something on the order of a sawmill or CNC controlled panel saw.

This aspect of code is geared toward industrial applications where a motor-driven piece of equipment is expected to be operating near FLA for the entire time it is functional. The varying load and varying duty cycle of a tablesaw puts it in the same category as a kitchen blender, or better yet, a router.

Taking this example, a router can have a rating of 14 or 15 amps, yet still come equipped with a NEMA 5-15 plug, and a UL sticker on the side. Actually, for that matter, a Delta Unisaw comes with a NEMA 6-15 plug pre-installed. If it was a code violation to put either of these tools that draw nearly 15 amps on a 15 amp circuit, then UL would not permit the product to leave the factory with a UL sticker when equipped with a 15 amp plug. If code required these tools to operate from 20-amp circuits, then UL would have required the tool to come equipped with a 20-amp plug on it to prevent the user from connecting the tool to an undersized circuit.

Don't get me wrong, I am not recommending that a 15 amp circuit should be used for a 3 hp tablesaw when there is a choice, but to say that a 20-amp circuit is required is not accurate.

[Mike Seals]

The breaker in your box should be sized to the gauge wire you are using. For example if your machine requires 24 amps...you'd better be using #10 gauge and you could use a 30 amp breaker. If your wire is #12 gauge you can use a 20 amp breaker .......The breaker is sized to the feed wire size not the motor.......Hopefully you have wire size and breaker size has a capacity larger than the motor you are using..........

The breaker is there to protect the wire. Over sizing wire just buys you a little insurance and spending more money. It's not uncommon to really over size the wire for voltage drop. We do it for small motors all the time where the distance is far off, say run a number 8 300 feet to a motor that by HP only needs a number 12, but the voltage drop would be higher than 2% with a number 12. 10 would work OK but to stay away from the drop we'll run an 8. Cicuit protection remains the same.

[Rod Sheridan]

Rick, I am in agreement with you, however as I stated I couldn't ethically recommend a 15 ampere feeder for the 3 HP saw because;

1) I have not verified that the saw will not be used in a manner that will exceed the 80% rule.....and...

2) I have not applied any engineering controls to prevent the saw from exceeding 12 amperes continuously such as a reduction in starter overload settings, written instructions and labels etc.

The 20 ampere feeder will meet all code requirements for any rated operation of the saw, period.

Providing engineering services for people has certain professional and ethical requirements.

I consider a written recommendation a defacto contract between myself and the original poster, and would expect that my recommendation incorporate due diligence. For me to recommend a solution that wouldn't survive peer review, would be unacceptable.

I'm not saying I disagree with your solution, in fact I would support it if I had fulfilled the obligations above.

Thanks for replying, I always find your posts informative and well written......Regards, Rod.