It doesn't matter if I use one branch (120v) or both (240v). It still causes the same heat and resistive losses in the transformer's coils. But the transformer was officially rated at 10 KVa, the new one is 25 KVa. They normally assume a balanced (i.e. 240v) load, since houses are supposed to be wired that way.
But given that I was drawing 123 amps at 240v, that's kinda an irrelevent issue for me ;-)
Almost all of it's on wheels. Some of it stays put, some of it moves every time I use it. And there are a *lot* of receptacles in the shop. :-)
Right, but since you're presumably installing multiple receptacles *anyway*, it seems to be that it's a lot less trouble to install, say, six receptacles of three different configurations, than it is to install six receptacles of the same configuration, *and* change somewhere between one and five plugs on your machines.
Less expense, too, because (a) receptacles are usually cheaper than plugs, and (b) n receptacles clearly cost less than (n receptacles + n plugs).
Why do you have to replace power cords "anyway"? I'm not following you here.
-- 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?
It has no business there, to be sure. But I've seen things like that often enough to have _no_ confidence in the proposition that they don't happen.
-- 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?
I did what you're proposing, and it works fine for me.
I bought a 3hp Unisaw, 2hp Rockwell planer and 1.5hp General jointer, all at estate sales. Each had a different 240V plug.
I put in a 30 amp breaker, 10 gauge wire and a 30 amp receptacle for this stuff. Eventually I'll probably put in more receptacles, but the jointer and planer tend to get moved each time I use them, so unplugging and plugging hasn't turned out to be too burdensome.
The saw came with a 30A twist-lock plug, so I standardized the other machines to that. I'd probably look for a lower cost option if it wasn't for already having a twist-lock.
The magnetic starters on the saw and jointer have overload protection built in and the planer has thermal protection on the motor. The jointer and planer could run on lower amp circuits, but, why bother putting in separate circuits just for them?
I've also got a 50 amp receptacle, but it's just for the welder.
I agree with others that running four wire circuits isn't necessary. If you decide to, just don't connect anything to the neutral wire lug in the plugs of 240V-only machines and you're fine.
In fact, before putting in a sub-panel, I had been running a cheater-cord (aka pigtail) that had a range cord and plug on one end and the twist-lock receptacle on the other. I didn't need a neutral, so just cut that lug off the plug. Disclaimer: you need to do two things if you try this: 1) understand that your range circuit is probably 40A, making your 30A receptical illegal, and, 2) have speeddial set to a nice restraunt if SWMBO comes home finding her stove unplugged one too many times.
Good luck,
Tim
"DL" wrote in news:Vp9ae.4312$lz1.1231@lakeread01:
I didn't want to cut into a brand new machine, if unneeded. And this was a brand new saw, since I couldn't find a good used one at the time, and was pi$$ed at the old one.
And I deserved it. 2002 was a tough year.
Patriarch, glad that's over!
I will have 15 240v outlets in the workshop area. My original thought was to go with the twist lock outlets so I would have been replacing all of the equipment plugs anyway. Based on your comments that the Twist Lock P/R's are not really required and can fall out if not properly locked, I will need to assess what I am going to do. If I decide to go with a blade style plug and receptacles and your recommendation of switching them up to match the plugs, my equipment is tied to the locations of those outets. Another thought would be to install both receptacles in a double gang box.
Given that I am doing the work myself finishing our basement, the savings of not paying a contractor more than covers the cost of plugs for many different pieces of equipment IMO. My comfort level that I have quality easy to use connections to my equiment is worth the extra cost.
If I compare the cord on my 240v air compressor with that of other the equipment that is rated for 120v and 240v but prewired for 120v, the cable difference is significant. I understand that the size of the cord varies based on the amps required by the equipment, but since I will be switching the wiring out at the equipment to make it run on the 240v power, installing a better quality cord makes sense to me instead of just replacing the plug end (obviously where needed).
--
That's an awful lot. I don't have that many 120V receptacles in mine, and I haven't found there to be a problem.
[snip]
The part that I think you're missing here is that a tool draws *half* the current at 240V that it does at 120V. Thus, for any given tool, the cord needs to be heavier for 120V use than for 240V. Your 240V air compressor has a heavy duty cord because it draws a lot of current, not because it runs at 240V. There's no reason IMO to replace the cord: if it's heavy enough to carry the current the tool pulls at 120V, it's already *twice* as heavy as it needs to be to carry the current the tool will pull at 240V.
-- 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?
But it does matter if it's rated at 40A at the voltage that is coming _out_ of it or 40A at the voltage that is going _into_ it. 40A at 5KV is a lot more power than 40A at 240V.
It was rated 10 KVa, I calculated 41A at 240v (output), or I suppose
1.4A at 7200v (input).I don't plan on attaching anything to the input side, except for the occasional squirrel.
Has more to do with the shape of the workspace than anything, not being the traditional rectangle shaped space.
I understand that the amps drop on the 240v equipment, and I probably used a bad example with the air compressor. A better example would be a comparison between my Delta dust collector and my Grizzly tablesaw. Both have 1.5hp motors, and both work fine, but the quality of the cord on the Delta is much nicer than my 12+ year old Grizzly. The general quality of some of the cords are not to my liking so if I have to replace the end to match a receptacle, I might as well upgrade the entire power cord.
Ah, I see. Of course, that's not an electrical issue. :-)
-- 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?
So I guess that the electric co is going to upgrade the feed to supply the
400 amps?? and install you your very own 100kva transformer?? ( not likely:-) ( guess that they could install a 75kva can as it will put out 360 amps and they allow about 125% overload on their transformers for a short time) So unless you get them to install at least a 75 kva transformer, you as the other posters have pointed out you are NOT going to be able to draw 400 amps from the feed. They will also have to increase the wires size for your service drop from the transformer to your home.William....
Here's what I did...I asked around as to what plug is the most common for 220v and installed electrical outlets that fit that plug. All my
220v tools have the same plug type and my shop has seven 220v. receptacles. I'd forget about the twist lock mechanism--the 220v plugs have enough friction that they stay in place. And when I need a new plug, there's one available in more than one store.
Well, I am mainly going by what the power company and certified electrician told me to do. Most of the homes in the area in the 5000+ square feet range are wired with 400amp service entrances as I am told. I will need a new meter head (which the electric company will supply and install) and the copper service entrance wires to the second 200amp main panel as well as the conduit to get it inside and grounding.
Our house was a spec house and the builder decided to cut back on certain things. They installed both boards for the 2 - 200amp service panels homes of this size generally install, but only installed one 200amp service panel, used all of the breakers except one in the main panel they installed. Not sufficient breaker connections for me to finish out basement to say the least. So to finish what the builder didn't do in the first place, I am taking the home to 400amps of service so that boxes are similar in size and will look proper when we go to sell the home in the future. Once installed, I will only pay for the electric I use whether or not it is a 200, 400, or for that matter a 1000amp (if there is such a thing) service.
Whether or not they already have or will install a separate 100kva system to ensure I can actually draw the full 400amps is yet to be seen. (Thanks for the heads up. I will be sure to ask the power company about it) I fully believe that I will never come close to drawing the full 400amps, but given the amount of electronics, appliances, and power tools, it's not worth the aggrivation and safety issues of circuits poping when I overload a 200amp service. Given that the first panel has over 800amps of breakers at this point, I don't think that it is unreasonable to the service upgraded. They are not going to take me to 250, my only option was to go to the 400amp service which I am more that fine with.
I guess what puzzles me with all the questions I have been getting about what I am planning to do will cost more or it is not necessary. I would understand it if I was going to do something that potentially dangerous, but to the contrary, I am installing what I believe (and people have agreed) is a safe (will have inspected to ensure it is) and flexible electrical system that will meet my needs now and in the future. Having all of my 240v connections wired with a minimum of 10 gauge wire might be more than is needed for a 15 or 20amp piece of equipment, but it will handle the load fine. If you only use a maximum of 100amps in your home, do you down grade the service entrance from 200amps to 100amps, I think not.
Having put additions on homes before, and gone through the sale process, I want to make sure that things are done right for safety first, but then I also want to take into account how it will affect the sale of the home. The cost difference between a 125amp load center and the upgrade to the second
200amp panel as well as the wiring, receptacles and plugs just don't add up to that much, especially from a safety factor.David
I think that is a good idea. Thanks for the comments.
David
David, I think a lot of guys are just looking at the plan for 400A service and scratching their heads wondering "why". Because most of us try to things in a safe, yet cost-effective way, I think it's natural for people to question it.
5000 sq ft is a big house. But there are plenty of homes around me in the 3000-3500 sq ft range, being built with 200A service. And probably a bigger factor than the size: are there more people living in the 5000 sq. ft. house than a 3000? More concurrent use of electrical power?The electrician who came out to inspect my last add-on circuit told me most of the newer houses with 200A panels will probably never even see 100A being drawn. They install a 200A service panel mainly to have more spaces for breakers. (and I'm assuming the cost for a 200A main breaker and the larger wire size in a new installation is relatively small).
But what's the cost of upgrading from 200A to 400A service? Compared to another solution like two 200A panels to make room for more circuits/breakers? Someone else's advice about a load calculation is right on the money. That's the starting point, and I'd be surprised if the electrician hasn't done it. If it were my money, I'd want to see the reasoning behind his recommendation.
Just my opinion.
You make a good point, but cost effective can mean different things to different people. The $400 I was quoted a year ago to upgrade the service doesn't seem excessive to me. Even if it was around $1000 I would still do it most likely as it brings my home into spec with similar homes in my area.
It all goes to what people do in their homes. I know people that live in their homes and don't do anything with them, but I am not that type.
Most people won't, but some will and for a limited cost that I am personally willing to pay, I would rather have the extra capacity.
The real cost IMO is the cost of the electrician's time to upgrade the service to 400amps and his materials, $400. Also, I would pay around $200 for the electrician to bond a second 200amp service panel to the existing
200amp panel if I just wanted to add more capacity for breakers. The electric company supplies and installs the new meter head, the electrician just needs to connect the service to the panel I already installed.The circuit analysis plans that circuits are not always under load, otherwise I wouldn't have close to 800amps of breakers in my existing 200amp panel. I will be adding some higher amp usage equipment in the workshop, garage, and moderate load equipment in my entertainment room that have a strong potential of being under load at the same time, that along with the other existing loads that can potentially come into play, I think the decision for me is a good one. Remember, I only have to need 201amps for the main to kick. Most people will never come close to that level.
As I stated before, they won't charge me for current I don't use. The power company has no real vested interest in doing this other than to sell me more electricity if I need it. Why would they go to the expense of adding a new
400amp meter head to my home if they were saw no potential whatsoever of selling me beyond 200amps of service at a given time? The electrician was contacted after speaking with the power company and the county so it is not a situation of an electrician trying to scam some unnecessary work.Also, if I find out 6 months from not that I do require more capacity, it will be much more expensive than what I am doing now.Personal experience plays a role as well. Having lived in a home that was underpowered, I am not willing to take the chance.
I think it is fair that people that obviously know more than I do about electricity would question what I am doing, but it comes across as if I am going to spend others money which I am not. Same types of discussions go on for equipment all the time. It goes to what a person is comfortable with. For certain equipment I am fine with the Grizzly products, but for others I want a different level of quality. Its what I will be comfortable with.
I truly appreciate everyone's perspectives and insights which help me make a decision, but the bottom line decision is mine, and I have to be comfortable with it.
Thanks,
David
Make it 150A and I'll agree. but hitting 100A is all too easy nowadays, when you start considering all the kitchen small appliances, personal computers and especially _printers_, and all the other 'consumer electronics' to be found in a home. individually, they don't draw a great lot, but there are so _many_ of them. Example, I've got *sixteen* 'counter-top' appliances in the kitchen. that's admittedly on the high side, because I am a bit of 'gadget happy' type, and, for example have two microwaves. Given that set-up it's not unreasonable that I might have 6-7 of them in simultaneous operation. at in excess of a kilowatt each. Plus maybe the dishwasher. Let the refrigerator and/or freezer decide to cycle, and I could hit 50A @ 240 just in the kitchen. Without considering a possible electric stove. :) Add the air-conditioning, and it doesn't take 'hardly anything' additional to go over 100A.
The incremental difference in the cost of the panel and main breaker is under $100 U.S. The cost of larger feed-wire from the transformer is maybe $1/ft. I doubt the total cost increment would exceed $1,000.
I find it _not_at_all_ difficult to believe -- i.e. that it *is* entirely reasonable -- that 200A would be insufficient for a property of that scale.
Postulate Central A/C, that's gonna be an easy 70A (at 240) right there. just for the compressor. (I grew up in a circa 1600 sq ft house, that had two-zone fully independent HVAC -- the AC for _each_ zone was a dedicated
40A circuit for the compressor; plus there was an additional 20A (120) A/C for a room that was exposed on 5 sides.)Throw in a couple of electric "major appliances", say a stove at 50A, and a clothes dryer at 30A, and you've got an easy simultaneous load of
150A.Now, lets add some other basic necessities: 1) The GFA furnace blowers, or circulating pumps for a hot-water radiator system -- for a house of that size, 15A (120v).
2) Washing Machine, to match the dryer :) 10A (120v) 3) Refrigerator 13A (120v) 4) separate freezer 13A (120v) 5) dishwasher 10A (120v) 6) garbage disposer 8A (120v) 7) trash compactor 8A (120v) 8) Microwave oven 10A (120v)There is roughly 90A at 120, or 45A at 240 We've now got a total load of 195A at 240.
And it is _entirely_ within the realm of reason that *all* those devices could be running simultaneously.
Without exceeding a 200A utility feed, you've got whopping _10A_at_120_ left, to run _everything_else_ in the house. Twelve 100-watt light bulbs.
You get a little more breathing room if the stove and clothes dryer are gas-fired.
For a 'demonstrator' model where, for example, major appliances that are present will _not_ be being used, I can see a developer 'cheaping out' with only 200A service.
Start adding in power demands for a 'serious' shop, and there's no doubt that 200A service is inadequate.
Yeah, 400A looks like overkill, but if it's the "next step up" from 200, then that _is_ what you do.
If 250, or 300 service was available, it might have been sufficient, but 'why take the chance'. probably 75% of the cost of re-doing things is in the labor. if materials for 400A cost _twice_ what 250A materials do, it's only circa 10% of the total bill.
This is called "*CHEAP* insurance" :) Particularly if amortized over the expected lifetime of the work.
In engineering terminology, the technical description for that situation is "a mistake".
Such things _do_ happen in the real world.
Remember: "There is no such thing as a 'fool-proof' system. For any attempt at devising such a system there is a *sufficiently*determined* fool that is capable of breaking it."
The 'pigtail' system described _can_ be deployed "safely", *IF* you follow a few simple rules. 1) All the in-wall wiring, breakers, and receptacles are rated for the draw of the highest-powered piece of equipment to be used. 2) The breaker has a load rating that is no higher than the minimum of the wiring rating, or the receptacle rating. 3) The wall receptacle rating is no higher than the wiring rating. 4) the 'pigtails' *always* have an 'equipment-side' fitting that is rated no higher than that of the 'wall-side' fitting.
If rule #1 is followed religiously, then 'strictly speaking', rule #3 is not necessary. There is nothing 'unsafe' about using higher-rated connectors for a lower-rated circuit *AS*LONG*AS* the circuit rating is not exceeded. There is a risk that 'at a later date', something will be introduced that _does_ exceed the circuit rating, with 'unfortunate' effect. This potential "down the road" problem is avoided by using 'right-sized' connectors. :)
[[.. munch ..]]
Your approach _is_ entirely rational and reasonable.
One thing I would suggest considering. "safety cords" (aka 'strain reliefs') across the connections, _whichever_ kind of connector you end up using.
Where cords are subject to movement, twisting, etc. "Twist-Lok" connectors _can_ come unplugged unexpectedly. Their primary 'advantage' is that they do *not* disconnect when subjected to a _straight-line_ pull. The secondary advantage is that they tolerate _large_numbers_ of connect/disconnect cycles better than "straight blade" types.
Something as simple as a piece of string/twine, knotted around the cord just behind the plug, and attached to a hook next to the outlet. Makes it _really_ difficult for the plug to 'fall out' of the socket.
HomeOwnersHub website is not affiliated with any of the manufacturers or service providers discussed here. All logos and trade names are the property of their respective owners.