Wrong plug end on this TS cord?

[lee cox]

6 ga wire is pretty big and expensive. It would probably be cheaper for me to replace my breaker box and use smaller wire.

I do have a 50 amp welding circuit which I could use.

[Art Mann]

I no longer offer information on house/shop wiring because it is difficult for people to tell who knows what they are talking about and who doesn't. All I will say is that you need to seek out an authoritative local source for advice because much of what has already been offered is just plain wrong.

[David L Morse]

I had licensed electrician wire my shop with a single 50A circuit with 3 receptacles (2 ea. L6-30R, 1 ea. 6-20R). It was inspected by municipality while I explained what it was for - single tool use. It passed with no issues or raised eyebrows.

I would like to string plugs together because I am out of breaker space. What size wire did you use? Was the wire sized to the tool or the circuit?

The applicable NEC section is 210.21(B)(3):
210.21(B).jpg
You can attach multiple receptacles to one branch circuit. They must all have the same current rating as the branch circuit except as shown in the table for 20A and 40A circuits.

[Randy Viellenave]

The 5HP motor requires 3.73KW, or 15.54A at 240VAC, so the plug is correct. The circuit should be just like most water heaters, AWG12 wire on a 2P 20A breaker. a 5HP 120V motor would be a rare thing, but I would check anyway and make sure you are wired for 240V 1P (single phase).

[lee cox]

The 5HP motor requires 3.73KW, or 15.54A at 240VAC, so the plug is correct. The circuit should be just like most water heaters, AWG12 wire on a 2P 20A breaker. a 5HP 120V motor would be a rare thing, but I would check anyway and make sure you are wired for 240V 1P (single phase).

I have a 3 HP Rockwell motor on my Unisaw and it draws 22 amps as stated on the metal plate on the motor for 220 volts.

I am wrong. I went out and looked at the motor plate. I tried to post the plate but I cannot insert an image. It is 16 amps for 220v and 32 amps for 110v.

[Randy Viellenave]

If that plate were correct, it would be about 6.5HP, so it is not correct. Each HP is equal to 746W (0.746KW) @100% efficiency. If you have 3HP, regardless of the voltage, you have 0.746KW X 3 = 2.238KW. If you are running at 240VAC, you would pull 9.325A, or double that to 18.65 @ 120VAC. You can draw a bit more due to an old motor or simply out of spec, but not that much more. I can see getting a 22A draw on startup, but that should be there and gone very fast.

[Wade Lippman]

If that plate were correct, it would be about 6.5HP, so it is not correct. Each HP is equal to 746W (0.746KW) @100% efficiency. If you have 3HP, regardless of the voltage, you have 0.746KW X 3 = 2.238KW. If you are running at 240VAC, you would pull 9.325A, or double that to 18.65 @ 120VAC. You can draw a bit more due to an old motor or simply out of spec, but not that much more. I can see getting a 22A draw on startup, but that should be there and gone very fast.

Total nonsense. Ignore the HP claim and wire to either the manufacture's recommendation or the amperage on the plate.

My 3hp Grizzly cyclone is 22a and my 3hp Sawstop is 13a; but I don't think any manufacturer is whimsical enough to claim their 9a motor is 3hp.

But in the end, I have to agree with Art; if you are asking questions like these, you shouldn't be doing wiring.

[Brice Rogers]

For the Grizzly 1023 with the 5 HP motor, Griz recommends using a 30 amp power source, a Nema L6-30 plug and says that the full load current rating is 22 A. You can look this up easy enough. Here's a link: http://cdn1.grizzly.com/manuals/g1023rl_m.pdf

There are lots of charts on the internet addressing "ampacity" and wire size. One from Cerrowire suggests using 10 gauge (solid) wire. http://www.cerrowire.com/ampacity-charts

So this is what you should use for wire from the breaker box to saw receptacle.

[Ole Anderson]

It was several years ago and done by someone else, but #6 copper (Romex) is rattling around in my head...???

There may be provision to use #8 THHN copper? But now you need conduit (if not in code, I'd certainly encourage it). I also recall something about wire smaller than #6 copper if it is for a motor AND it has overload protection AT the motor...?

Caveat: I'm not an electrician! Nor do I have NEC rules as a tattoo. Please consult an expert. And legal in one jurisdiction, is not always legal in next.

10 gauge copper is good for 30 amps unless you have a very long run. 10-2 wg NM cable (romex) is generally jacketed in orange.

[Ken Combs]

If you really want to get confused, Google L6-30 Horsepower (or HP) rating. According the NEC ratings, none of my plug in stuff above 2HP is legal.

amperage rating and HP ratings are not what most of us think. At least in the legal NEC world.

[Wade Lippman]

If you really want to get confused, Google L6-30 Horsepower (or HP) rating. According the NEC ratings, none of my plug in stuff above 2HP is legal.

amperage rating and HP ratings are not what most of us think. At least in the legal NEC world.

I noticed that a few years ago and asked Grizzly about it; their recommended plugs were inadequate to the HP ratings. They told me to ignore the HP rating and go by amperage. I guess that ties into the capricious nature of claimed HP ratings.

[Ken Combs]

I noticed that a few years ago and asked Grizzly about it; their recommended plugs were inadequate to the HP ratings. They told me to ignore the HP rating and go by amperage. I guess that ties into the capricious nature of claimed HP ratings.

I don't think it's the hp rating, as the 'phantom ratings' are limited to brush type motors and air compressors. Even in those, the motor makers don't do the lying, it's the air compressors makers that attach the fake numbers...Most, if not all the mis=rated units say one thing on the tank, but the motor will say 'spl' (for special) or some other non-numerical phrase.

It's my guess that the NEC rule makers considered the possibility of a plug being removed while a motor was starting under load. the resultant arc flash of say a 5hp would be really hot!

High HP sockets and plugs are available as are 3ph plugs/sockets but are really expensive.

i think any equipment maker that encourages users to ignore the NEC is technically right when the usage is considered, but there is a liability risk if something should go wrong.

[Robby Tacheny]

Lower amps = smaller wire (when wired correctly)
Higher amps = bigger wire (when wired correctly)
20amps at 110v = 10amps @ 220V (when wired correctly)
110v = One "hot" leg from breaker box (when wired correctly)
220 = Two "hot" legs from breaker box (when wired correctly)
3 Phase = I get confused

These are the ultra basics. Get some testing tools (probes that tell you if a circuit is hot and tell you voltage; maybe an clip on amp meter if want to check a running tool in that outlet) if you are going to do work your self. Check outlet before working on it with testing tool and check again even after flipping breaker before you work on it.

Check your local laws and building codes and follow them. Get help if you don't feel comfortable with all of this.

-Robby

[lowell holmes]

I'm not an electrician, but if I remember correctly from my house building days, #12 romex is rated for 20 amps, 30 amps would require #10 conductors.

An electrician needs to confirm this.

[John Lankers]

With the new Griz 1023 in my garage, it's time to plug it in and tune it up however I've run into a little bit of a conundrum.

Not being super savvy on electrical stuff but having googled it a bit, I've managed to make myself more confused while trying to figure this out.

My saw came with the plug in the photo below. This appears to be an under spec plug for the amperage of the saw (5HP model, 30amp). Am I correct in this statement?

Also, it doesn't match the 240 receptacle in my space which looks more like the dryer plug style receptacle. I'm planning on installing a new receptacle in the wall beside my saw (because it's directly adjacent the fuse box, I'm assuming this will be superior in all ways to running cord from the other corner of the garage (20 ft) to my saw.

The question is: what plug end should I be using? Also, the breaker is 30amps which might be a touch on the low side for when the saw first fires up. Should I beef that breaker up as well?

Attachment 342776

To get back to the original question, this plug is a fire waiting to happen.
The ratings are engraved on the plug (usually on the face), what you want is a 30 Amp, 250 Volt rated plug, there are choices like a 30 Amp welder plug or a 30 Amp twist lock plug.
Next point, your 30 Amp breaker was installed to protect the wiring leading to the receptacle NOT the tool you plug into it that is your responsibility. If the breaker trips when you turn the saw on or work it hard talk to a qualified electrician.