220v Plug End Replacement for Equipment

I am curious as to what others have done for receptacles that are going to be used with different equipment that have different plug configurations. As an example, I am going to install a 30amp 220 receptacle that will be used by my finishing (sanding) machine, current air compressor, and the replacement larger air compressor which have different plug end configurations. Since I really like the ideal of the solid connection the twist lock style receptacles provide for the equipment, I will have to change the plug ends or complete power cords on all of my equipment.

To my knowledge IIRC, all of the woodworking equipment runs strictly on 250v (3-wire confirguration) as compared to appliances that can run on 125/250v (4-wire configuration) such as a range. Even so, I would figured that going with the 4 wire receptacles gives me the most flexibility in case a piece of equipment does use 125/250v that I am not thinking of now. Wiring from the panel to the receptacle box was done with 10/3 for the 20-30amp connections and 6/3 for my 40-50amp connection.

When I replace the plug ends to match the 4-wire receptacles, if the original plug end was three prong (2 live and a ground), I obviously will only be able to wire the 4 wire twist lock plug with the 3 existing wires from the equipment power cord. Will there be a problem with the Neutral connection not being wired on the plug side even though it is wired from the panel to the receptacle. It should be noted that I am running these connections from a subpanel where the ground and neutral wire bars are separated.

The goal if possible is to use the same type receptacles on all outlets around the shop to allow for maximum flexibility in re-arranging the shop based on future needs and uses.

Any recommendations / comments would be appreciated.

David

Reply to
DL
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"DL" wrote in news:2o_9e.3906$lz1.1060@lakeread01:

Caveat #1: I am not a registered or licensed electrician, although I did consult one.

Caveat #2: I know it is stupid to respond to a wReck discussion of electricity, due of the risk of involvement in discussions in which others are or claim to be more expert.

Caveat #3: You asked an opinion, and I have one to offer.

Caveat #4: I have a hobby shop, not subject to local government or insurance regulatory safety inspection.

My well-supplied, and well-respected local hardware purveyor assisted me in selecting the appropriate, high quality parts to make up pigtails to match the wall box socket to an appropriate female end. I use this to do as the Safety Saint earlier described, to have a visible and controllable means of making CERTAIN that power is disconnected, before I put body parts into the innards of a machine which can damage said parts.

Such pigtails are disconnected when the shop is closed down, or I'm finished with the use of the machine for that session. Even with 110V, on the cutting tools.

Patriarch

Reply to
Patriarch

I installed receptacles with the configurations needed for the plugs on the tools that I have.

IMO, the twist-lock plugs are not really necessary. In fact, a twist-lock plug that is *not* fully twisted and locked is much *more* likely to fall out of its socket than is a standard plug. I've never observed any of my standard plugs to come out of their receptacles unexpectedly.

Entirely correct. However, it's flexibility that you don't need, and, if it's not done correctly, there is a potential hazard. If you're going to do this - and I wouldn't - you MUST use receptacles and plugs that are rated for the HIGHEST amperage circuit in the shop. To do otherwise would make it possible to, for example, plug a tool drawing 40A into a receptacle rated for only 20A, on a circuit that can safely carry only 30A.

And, of course, every time you buy a new piece of gear, you're going to have to change the plug on it.

What happens if you, sometime later, buy a piece of equipment with a higher amperage rating than anything you have now - and higher than anything you have a receptacle rated for? You'll need to install a new receptacle with the correct rating, and, perforce, a different configuration. And then your interchangeability is out the window, unless you replace all your plugs.

That will be no problem at all. If the equipment doesn't need the neutral, it doesn't need it. And if it does, it's there.

However, I think this is completely unnecessary. Not to say they don't exist, of course, but I haven't yet seen a piece of woodworking equipment that has both 120V and 240V loads, and it's hard for me to imagine one that would. On a range or a dryer, the neutral is needed because the heating elements are 240V, but the lights, timer, etc. are 120V. The electrical components of woodworking tools typically consist of a motor and a switch. A 240V motor has no need of a neutral.

I wouldn't do it. To sum up:

- unnecessary expense and effort to replace multiple plugs

- twist-locks are not needed (another unnecessary expense)

- risk of fire if amp rating of receptacles not matched correctly to tools

- no need for neutral on 240V tools (more unnecessary expense)

-- Regards, Doug Miller (alphageek at milmac dot com)

Nobody ever left footprints in the sands of time by sitting on his butt. And who wants to leave buttprints in the sands of time?

Reply to
Doug Miller

As long as those pigtails don't make it possible to do something like plugging a 30A tool into a 20A receptacle on a 20A circuit, that's fine.

If they *do* make that possible, you have a *serious* hazard.

-- Regards, Doug Miller (alphageek at milmac dot com)

Nobody ever left footprints in the sands of time by sitting on his butt. And who wants to leave buttprints in the sands of time?

Reply to
Doug Miller

Nor am I, and this is why I am asking for some opinions / guidance and will have the work I am doing inspected by the county inspector as well as a certified electrician that will be upgrading the main service entrance from

200amps to 400amps needed for the entire space being finished much beyone my workshop area.

Well, I like to see responses from all so that I can make my own decision as to what will work best for me. Ultimately, in my case, the final word comes from the county inspection office as to what they will approve.

Thanks for responding with your opinion.

Not sure where you live or the jurisdiction rules, but any place I have ever lived required inspections for wiring changes / additions for anything more that changing a switch/plug or adding a fixture to an existing box, hobby shop or not. I do agree that changing the plug ends is not something that would require inspection by a county inspector, but wiring the receptacle and the wires that run back to the subpanel do require approval from the county inspector where I live.

I guess I am confused with your reference to a pigtail. In my understanding, a pigtail is used inside the junction / receptacle box to connect multiple wires to a single terminal connection. Are you referring to the plug ends I spoke about? If not, did you make short "pigtail" connection that would change the plug configuration of your equipment plug to the configuration of the receptacle so that you didn't need to cut and rewire the plug ends of the equipment power cords?

I guess I am confused with your reference to a pigtail. In my understanding, a pigtail is used inside the junction / receptacle box to connect multiple wires to a single terminal connection. Are you referring to the plug ends I spoke about? If not, did you make short "pigtail" connection that would change the plug configuration of your equipment to the configuration of the receptacle so that you didn't need to cut and rewire the ends of the equipment plug ends?

Reply to
DL

Love the caveat, and the pigtails idea. Both are great ideas. Used the pigtails before in boating to match shore power...

Some good things _do_ come from California -- see? :-)

Reply to
WillR

Ummmm.... maybe you ought to ask that certified electrician to do a load calculation first. What on earth do you want with 400A service? 200A should be plenty.

Just for reference, my shop contains the following:

- table saw, dust collector, shaper, lathe, and air compressor (all 240V)

- band saw, radial arm saw, belt/disc sander, spindle sander, drill press, mortiser, jointer, planer, air filter, and an assortment of portable tools (all 120V)

SWMBO and my kids also enjoy woodworking, and it's not uncommon to have two of us in the shop at once, with two different machines *plus* the dust collector and air filter in operation simultaneously.

And the whole thing (except lights) is fed from a subpanel on a 60A feed. That subpanel *also* feeds the washer, [gas] dryer, and electric stove (240V).

[snip]

He's talking about a short extension cord, with the plug end matching the receptacle in the wall, and the receptacl end matching the plug on the equipment. This is, of course, an even *greater* unnecessary expenditure of money and effort than the plug replacement that you propose, and carries exactly the same risks if the plug-and-receptacle configurations of the pigtails are not matched correctly to the tools and the circuits. As long as the configurations do not enable plugging a 30A tool into a 20A circuit, for example, it's OK, but you *must* make sure of that.

-- Regards, Doug Miller (alphageek at milmac dot com)

Nobody ever left footprints in the sands of time by sitting on his butt. And who wants to leave buttprints in the sands of time?

Reply to
Doug Miller

snip

snip

400amp service? Are you running an aluminum smelter?
Reply to
TaskMule

Why? Wouldn't the 20A circuit have a 20A breaker, which would trip due to the 30A load? You say "Doh!", reset the breaker, and plug it into the correct outlet and go on...

-j

Reply to
Joe User

One *hopes* the 20A circuit has a 20A breaker, anyway... I should have stressed the importance of making sure that the ratings of the breaker, the wire, and the receptacle all match.

-- Regards, Doug Miller (alphageek at milmac dot com)

Nobody ever left footprints in the sands of time by sitting on his butt. And who wants to leave buttprints in the sands of time?

Reply to
Doug Miller

"DL" wrote in news:Zm6ae.3927$lz1.2661@lakeread01:

Think 'short extension cord', external to the building wiring.

All of the 240v circuits were 30A, installed, by a licensed, bonded, insured electrical professional. Who installed a subpanel, with lockable master lockout switch.

Sorry if my inaccurate, or irregular use of the language caused confusion. It was not my intent.

Patriarch

Reply to
Patriarch
Re: 220v Plug End Replacement for Equipment open original image

Just FYI we got the "default" 200A service, even when the engineer from the power company recommended 300 or 400 amp (because of the woodshop).

200A service does NOT mean you can comfortably draw 200A!

Our "200 amp" service included a private transformer (long driveway) that was only rated at 40 amps continuous. Each time the central air kicked in, the 123 amp surge (30 amps after that) caused brownouts and eventually motor failure in the AC.

After replacing the AC unit and a number of tests and tweaks by the power company, they ended up replacing the 40A transformer with a 100A transformer - which is what they usually use for an entire neighborhood.

So, switching to 400A service means more than just needing 400A. It also means a bigger transformer, thicker wires, etc - all leading to cleaner power during surges, less brownouts, and less chance of burning out your motors.

Reply to
DJ Delorie

40A continuous at what voltage?

Reply to
J. Clarke

If it's a breaker and not a fuse. If nobody has stuck a slug under a burnt-out fuse, if the breaker is in fact working properly. Lot of ifs there. Breakers and fuses are backup--they are there for when something goes wrong. Depending on them instead of proper procedures is dangerous.

Reply to
J. Clarke

I have spoken with a certified electrician, the electric company, and the county inspector on upgrading my main service to 400amps from 200amps and all agree that it should be done. The service upgrade is for the entire

5000+ square foot home. The current 200amp service panel is completely maxed out. I am in the process of finishing a 1500 square foot basement of which around 500 square feet are dedicated to the workshop. I have a full bath and media and other rooms, connections to the garage that need power circuits which justify the additional service upgrade. Having lived in homes that are under wired, the cost difference to get what will meet my needs now and in the future is well worth the minimal increase in cost for the heavier wire, breakers, and panels.

For the workshop specifically I am installing a subpanel with a 100amp circuit from the main panel to cover my needs in the workshop. Given I have a rotary phase converter that requires a 70-80amp breaker alone, along with the other 30 and 50amp circuits I will be running, I don't think this is too outrageous. To me, it is a lot cheaper to go on the high side now than to have to redo wiring later once the walls are closed in.

Reply to
DL

See my response to Doug.

Reply to
DL

Sounds like you dont move your equipment around much. I do based on space limitations. While a good portion of the circuits will be dedicated to specific equipment and I can match the receptacle to plug, some outlets are being installed with the expectation that several pieces of equipment will be used on them. Just as one would wire 20amp 110v circuits instead of

15amp to be able to power all 20amp and below 110v equipment, I plan to do the same with my 240v equipment. The rub comes in with the 240v receptacles and plugs is that they have different blade configurations depending on whether or not they are a 15amp, 20amp, or 30amp and beyond pieces of equipment.

I probably didn't make it clear before, but I plan to run 10/3 wire with ground from 30amp breakers for all my 30amp and below (multiple around the shop) connections. I plan to run 6/3 wire with ground from a 50 amp breakers to handle the equipment that runs at more than 30amps but less or equal to 50amps (one for the larger air compressor as Lew H recommended and an extra for other equipment that requires up to 50amps).

Given that most of the equipment runs on either 125v or 250v, I will have to replace the power cords anyway. This will allow me to go to a common plug and receptacle that gives me the flexibility to move my equipment around.

This is good input and why I asked the question originally. They are on the pricey side, but I wouldn't mide the expense if they were a better connection. Doesn't seem from your input that they are worth the extra expense.

My clarfication of what types of circuits I am installing on what type of wire above covers this.

Depending on the type of recpeptacle I decide is my standard, I might or might not have to make a change. Again, most of the 240v equipment I have purchased works on 120v and 240v, but they come wired for 120v. I would need to replace the cord anyway so the plug is a moot point then. The added time or cost for the plugs or cords is not that significant to me given the equipment generally runs in the just under $500 on the low end, so a $10 - $30 plug end or cord assembly doesn't seem to much to me.

Based on what I have currently for equipment, the fact that I have am installing a centrally located 50amp circuit, and my planned purchases in the forseeable future, I will be covered. If I do need something higher, I will install a circuit for that at the time. The subpanel or main panel will have the space and capacity I need.

This is what I thought, but wanted to be sure.

To me, it's cheap enough to run the 10/3 w/ ground and 6/3 w/ ground now so that in the event something does require it, I don't have to rerun circuits. I can always cap the neutral off in the receptacle box and install a receptacle that uses the 2 lives and the ground.

Thanks for your comments,

David

Reply to
DL

No problem, it's what I thought you meant, but wanted to be sure.

It is an interesting idea and I like the concept. Is there a reason you didn't want to just replace the entire cord to the machine or at a minimum just the plug end as I proposed?

If you were going to use the equipment in areas that have different receptacles types, I think this is the best option. Given that I am trying to standardize on a receptacle type, it seems to me you are doing both sides when you would only need to do one.

Did you want to leave the original power cord and plug end in tact for warranty purposes?

Thanks,

David

Reply to
DL
[snip]

What's a 20A receptacle doing on a circuit fused at 30A?

Reply to
Wes Stewart

I think you should go ahead and put 30A and 50A rated sockets on the 30A and 50A circuits respectively. Chose twist-lock or not as you see fit. Then just put matching plugs on the equipment as needed. If there is no nuetral on the machine, you just leave that one unconnected in the plug. Make sure you have a good ground connection. All of this is safe and legal. Just don't put a 30A plug on a greater than 30A machine. The two different rated sockets/plugs will not physically fit into each other so as long as you don't put the wrong plug on a piece of equipment you will have no problem.

Bill Ranck Blacksburg, Va.

Reply to
ranck

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