Besides the "L" being cut off so it can be inserted into a range receptacle and the loose screw on the locking device??

Their biggest mistake was leaving it to be found by a member of this website.

We have a picture of it now!!

They're fair game for the slaughter, men; HAVE AT THEM!!

One thing that comes to mind is typical range cords are listed for Domestic Range use only and even though they fit a 50 amp receptacle the wire inside them is not rated for 50 amps. In this case the load from the Sander won't exceed the ampacity of the cable. I appreciate that these guys go into someone's house with little or no hope of finding a correct rated outlet for their sander and resort to this. It is infinitely better than the guys who pull the cover off the panel and connect direct to a breaker in the panel. In a perfect world a cord adaptor would be available with an o/c device rated for the sander.

It's missing the battery jumper cable clips to clamp on the panel busbars? A few years ago I saw one clipped to the line side of the main fuses for a 5-story building that shared the pig with half the block. Yikes!

I don't know about that. The last time I looked at a NEMA 14-50 range cord, the hots were 6 awg, the neutral was 8 awg, and the ground was 10 awg. Table 400.5 states the ampacity of 6 awg(whatever type of cord other than TPT, TST, HPD, HPN, etc, etc.) as 45A for Column A (more than 2 conductors) and 55A for Column B (2 conductors). Since a floor sander uses only 2 conductors, it doesn't matter that the cord came from the factory with 3. I wouldn't nitpick. I'd just give that floor sander guy a medal for being the first floor sander I've ever known to actually bother to try to do things right, instead of reflexively reaching for the %^$#&^% alligator clips when there is already a range or dryer outlet available!

Besides, the nameplate current of a 5hp motor is 28A according to Table 430.148. That means there is nothing wrong with using it on a 30A circuit, as long is it is not a continuous load (and isn't the continuous load rule waived under Article 527 (temporary wiring)?

An example of where the standard range cord would be inappropriate at 50A would be for an RV, since the full neutral ampacity is needed. (Never mind that a 6' long range cord would not be of much benefit as an RV extension cord!)

OK, my mistake, it's a dryer cord, so all the conductors are 10 awg. So, I repeat, has anyone ever seen a floor sander that was over 5hp?

Can we assume that the floor sander contains running overload protective devices? I've never actually studied one that closely, but these things are manufactured by businesses that have to worry about product liability, and I assume their product is listed, so let's say yes.

That leaves branch-circuit short-circuit and ground-fault protection. Table 430.52 says that for an instantaneous-trip breaker (realistically the norm in any residence nowadays), the maximum percentage of full-load current is 800%. 800%*28A>50A. Did I do that right? Article 430 is probably the trickiest article in the NEC, I don't use it all that much, it's late on a Friday night, and I've had a few brews. Even if I'm wrong, I have to give credit to the floor sander guy for at least trying to get it right.

The adapter is for a 'Hummel' sanding machine.

I've seen Hummels powered up with stripped back and stabbed in conductors (!)

Panel break-ins only occur when no dryer outlet is to be had.

7.5 HP floor sanding machines are available, one is made in Canada.

The scary thing for refinishers is discovering how many old homes are seriously miss-wired... the hard way: shocked by the ground plug.

Not to worry about motor overloads: all of the machines are self protected at levels that assure the health of the 'taps'. These are not unattended machines.

What would be worthwhile would be a plug tester suitable for the need so that these contractors can verify that the receptacle/home is correctly wired and that have a GFCI in-line to their equipment.

Some things are most definitely easier here... the Hummel is made in Germany (by the way, Hummel means bumblebee) and here those things plug into a 230V 16A Schuko receptacle available in almost every place (only some real old places only have 10A fuses).

I have to admit I agree with those of you that say this is better then the alligator clips-to-main lugs I see all too often

Assuming they need 230V and say 20A for their sanders what do y'all suggest they do - call an electrician? If a flooring company said to me we need to get an electrician out to your house so he/she can install the correct outlet for our equipment (and by the way you are going to pay for it), I'd tell 'em to go jump in the lake. So lets hear some real honest to goodness practical suggestions what would y'all do?

The flooring contractor could bring a generator and enough cord to do the job.

That is how many cement cutting and coring companies handle this problem.

I really don't even have a problem with the cord above. I do have a problem with the use of alligator clips on the main. Keep in mind that if they blow stuff up it will be your panel that needs replacing.

Exactly. If you have a machine that requires a voltage and/or amprage that you will not normally find an outlet for in a building, it is YOUR responsibility to bring your own power! Not doing this is just unprofessional, IMHO.

Trust me, this adapter cord is a GREAT improvement over most sander connections. Most are rigged to the breaker box, across the hot side of the main. Also since this is a motor, would not the breaker be sized to the HP of the motor, not the wiring size? Robert

It’s a pretty clever solution to their power needs and it beats the hell out of the alligator clip hack. If it were my house I would let them use this, the worst that could happen is their equipment and cord past the 20A twist lock is not protected, and hopefully the motor would have some overload protection.

Sure some contractors have generators, but which bid did you select the high guy with then generator, or the low guy with the home made cord adapter?

Not to mention that portable generators in high-rise buildings without external fire escapes are kind of useless.