Performax Supermax 25x2 drum sander

Hi everyone,
I have a question I was hoping a member could help me with. I recently acquired a Performax Supermax 25×2 sander for free. I’ve had to put some $$$ into it as it was not stored well and some things have rust and pits. Anyway… my question is regarding the electrical connection. I live in MN and I’ve contacted the new Supermax tools company for parts and electrical info. I’m told I need a 30amp circuit. I was also told I need a 4 prong plug, 2 hot, 1 neutral, 1 ground. All of this makes sense. Except for my machine has a 20 amp 240v plug with only 3 prongs. I know the plug was replaced by someone else as there is a price tag on it. The electrical cord going into the main control box is 12/2 (2 hots and one ground). For a 30 amp circuit I thought the cord should be 10 gauge??? On the circuit board there are only 2 connections and a ground. I have a feeling on the older designs they used only 3 wires instead of 4. Here’s what I’m hoping someone can help me with. If anyone has this sander would you be able to post a picture of the correct plug and cord gauge for me? I always thought 10 gauge was for 30 amp and 12 was for 20 amp. I don’t want to put a 30amp plug on the machine when it was meant for 20amps.
Thanks for all of the help everyone,
I really appreciate it.
Eric

My sander has a 220/20 amp plug(original), which is about the size of a 110v plug but the 2 non-ground connectors are perpendicular. There are several versions at my electrical supplier but as long as you get a matching plug and outlet you are good. 12 g wire.

Mine is on a 20amp/220v breaker.

If your sander will stay in one place you could also hard wire it.

If Supermax said you need a four prong plug it may imply that your model powers the feed motor differently then Superman models perhaps (?). That would seem overly involved and I would double check the source of that info.

Thanks for letting me know. The olders Sanders must’ve been a 20 amp circuit instead of the new 30 amp circuit. That works well for me. That would also make sense why the cord going to the power box on the sander is only 12 gauge. Is this the style of plug you have? Nema 2-20p

https://www.graybar.com/store/en/gb/black-white-straight-blade-plug-industrial-grade-20a-250v-2p3w-92044902?cm_mmc=pla:google-_-googleshopping-_-gb5419-_-92044902&utm_source=google&utm_term=&utm_campaign= Graybar%3EPLA%3ECategory&utm_medium=cpc&utm_conten t=FH5FINLl%7Cpcrid%7C49843842170%7Cpkw%7C%7Cpmt%7C &gclid=EAIaIQobChMIh8a05_Hs1wIVWVgNCh0FnAwIEAQYAyA BEgKX4PD_BwE#{Voltage%20Rating:250V}&{Color:Black/White}&{Amperage:20A}&{NEMA%20Rating:NEMA%206-20P}&{Number%20of%20Poles:2-Pole}&{Number%20of%20Wires:3-Wire}

The new Supermax Sanders do use a four conductor wire. I could even see this in the wiring schematic they have posted in the manual. It must be a different than the older sander that I have. The plug that was on my sander was a 220 V 15 amp plug which I knew was wrong.

Quote:

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Is this the style of plug you have? Nema 2-20p

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That's the one

Eric,
I just purchased the same sander used and had similar questions. Mine had the power cord, but no plug on the end. The cord was 10 gauge, with 3 conductors (black, red, & white) and ground. I had planned to use a 20 amp plug to match my existing outlets. I ended up using a Nema 6-20p plug. The plug takes 2 hot conductors and a ground, so I was unsure what do do about the neutral (white) wire in the cord. I thought it was meant to be left unconnected, but wanted to be sure. I downloaded the user manual from Supermax, and it confirms that the neutral wire in not connected in either single or 3 phase 220 volt operation. They say it machine comes with a Nema 14-30 plug and receptacle. Perhaps it did when new.

They do recommend a 30 amp circuit, even though a 5 hp motor will run on a 20 amp circuit. Depending on your voltage, it could drawn 15-18 amps, so they probably recommend 30 amps just to be safe. Here is a link for the manual if you need it.
https://www.supermaxtools.com/wp-con...al-10-2015.pdf

According to "Code", if there are any devices ( boards, control circuits, etc) a 0 voltage conductor (neutral) must be used. Ground wires may no longer be used as current carrying conductors, except in a short circuit to ground of course.
Hope this helps,
Rollie

My local electrical inspector schooled me on this a bit. Most of it was over my head, however, I got two take aways from our conversation. It's OK to run an older appliance/machine using just the two hot legs and the ground and having the white/neutral capped off in the box. It is not OK to run a newer machine/appliance, one that is set up for 3 conductors + ground, on an older 2 conductor circuit. The way he explained the loads are changing from resistive to conductive or inductive. Again, it was over my head but he got his point across.

The second take home I got from our conversation is a general rule of thumb to not exceed 70% of a circuits rating. Pulling a maximum amount of amps through a wire can/will lead to excessive heat buildup and failures of various designs. 18 amps is more than 70% of a 20A circuit so should be run on a 30A circuit. Since I live in an extremely rural area I prefer to err on the side of caution.

I noticed when I was hooking up my bigger machines in my new shop that the cords leading into them were a gauge less than the recommended circuit breaker size. My PM dual drum sander, for example, suggested a 40A circuit but used a 10 gauge cord from the factory. My shaper suggested a 30A circuit but used a 12 gauge cord, etc. Perhaps because it's the last leg in the electrical journal or maybe that it's not inside a wall (amid heat preserving insulation). I don't know but the electrical inspector signed off on all my hook ups which means IF I have a fire at least I'll be able to collect my insurance.

Brian,
The link you provided is what I downloaded. From the schematic that I see it looks like the White wire is connected to line 3 for single phase. I’m not seeing where it is capped off. I’ll run a 30 amp circuit and use the 20 amp plug and wire that came with the sander. At least the circuit will be more than enough to handle the load.