System Disconnects

[WStayton]

rcavictim:

 As usual, you raise some interesting points.

 About the leagailty of using individual fuses as disconnects for each, of two, phases:  I don't have to tell them that they are in the system as disconnects, and I'm not above telling a little white lie, if it furthers my cause!  (So much for truth, honesty and the American way!  <grin>)

 I could put the fuses in the circuits and just not say anything and let the inspector draw his own conclusions - that's with a big IF, though. . . if the type of fuse puller proposed by BioHazard to pull the fuses will do the job for me - I have never used a fuse puller in any size for any fuse, I've always just used a pair of insulated needle nose pliers, as also suggested by BioHazard, but, while this may be adequate on a once in a great while basis, I don't think it is a workable solution for somebody with impaired grip and hand/eye co-ordination on a daily basis - my  experience has been that when you ask for trouble, you invariably find it!  <grin>  My impairment is slight, but it just might be enough to cause me to have a problem with needle nose pliers on an every day basis.

 As far as legality - is it legal, per NEA, to put fuses in a circuit that doesn't otherwise require them just because you want them there?  I THINK that they would be legal if you kept you mouth shut about using them as disconnects,  but Regulations are not always the most logical things on the planet . . . is anybody actually conversant with the NEA?

 I suppose the real test is to ask the inspector involved, which I will do, when he stops by this week for his weekly "check-up" of my activities.  He said, when we started the process, that he would like to see things when they were half done, just to assess what kind of job I was doing and to make sure that I wasn't making a big-time screw-up.  I countered with an invitation to take a look once a week, just to have somebody looking at what I was doing, to make sure that I DIDN'T screw-up.  He seemed pleased by this suggestion and on his two subsequent "inspections" he has basically just shot the crap with me for an hour, asked if I had any questions, and taken a very cursory look at the progress to date.  His comments so far have been that I was far to meticulous to make any moiney as an electrician, and that he thought my proposal to mix conduit with Romex was a novel and labor effecient solution, but probably would never make it commercially because I will use something like twice as many interconnect boxes as a system that was done in either one or the other.  He said that since he wasn't writing the checks for the suppliues, he has no problem with me mixing the two methods, but it WAS the first time that he had seen it used for a whole project.  So, when he shows up this week, I will ask him if he will ok it if I put an individual fuse in each line of the incoming 120/240, the incoming neutral and the two 120V lines from the generator.  That way I will know, absolutely, positively, for-sure whether what i want to do is permissable or not.

 If he asks why I want ANOTHER interrupter device in the system on the incoming and generator lines, I am kinda going to be up a stump - I don't really want to tell the guy an outright lie, since he is pretty sharp, and could well catch me later, and I think that once I have pee'ed down his leg he may be less co-operative. On the other hand, I could tell him that I have misgivings about the performance of circuit breakers over a period of time (which IS true, though I THINK that they will degrade to  trip at a lower current, not a higher one!  <grin>), and so I just want the fuse's in the circuit to be absolutely sure that the circuit is protected.  Maybe I can just sort of gloss over this one and not go into a lot of detail and see what happens?

 Meanwhile, anybody who has used a "fuse extractor" on a 100 amp fuse, please speak up!  How well do they work and is it a device with which a slight physical impairment will have a problem?

 Gee, I'm glad I asked you guys!  You are just a well spring of ideas, of various values (rcavictim - dig, dig!  <grin>)

 Oh, and rcavictim, I am EXTREMELY jealous of your stock of pieces/parts - it seems like if a B-1 made an emergency landing in your yard and announced the he needed a scatafremeracque to complete the mission, you would calmly go into the back room, root around for a few minutes and return with the desired piece!

 Thanks for the input, guys - maybe I will even save a few bucks! <smile>

Regardz,

Wayne Stayton

[WStayton]

BioHazard;

  The disconnects that you have listed are something like 3 to 4 times as much money as a set of 100 amp fuses and fuse holders would be.  Im not sure that I can justify spending a hunderd bucks just to make life easier for me!  <grin>  I am willing to work a little to save a hundred bucks! <smile>

  The " giant pin and sleeve connector " is an interesting approach but I think I would have a hard time convincing the inspector that it was to protect the system!  Even if what it was protecting the system from was an EMP!  And, I bet they will cost more than a simple holder and fuse.

  As you might be able to tell, the fuse idea has struck a chord with me and I will investigate using this approach until either 1) It doesn't look like it is suitable for my physical condition, or 2) It won't be allowed/approved by my inspector.

  Thanx for your input - if the fuse idea proves unacceptable, my next thought is to use exactly what you have proposed with the disconnects.  I would just need one 3 phase and one 2 phase for the line and generator, respectively.

  As always, all inputs are solicited and appreciated!

Regardz,

Wayne Stayton

[BioHazard]

You sound like me Wayne, whenever I mention a passing simple thought about one of my projects it turns into a whole ordeal with ten different engineers trying to solve it. I love this forum...these guys have saved me some cash more than once.

[WStayton]

BioHazard;

  One thing that I have come to REALLY like about this forum is that you can ask ANYTHING and 1) Get an answer - you may not like the answer you get, but you will get one, or, more likely, several suggestions.  2) Not have to worry about asking things in a carefully worded non-chalant way so as to not arouse the suspicions of the powers that be with regard to control of your project.

  I've got a pretty good relationship, at least so far <grin>, with my code inspector, but when talking to him a keep a pretty tight leash on my big mouth in an effort NOT to arouse errant suspicions.  If your inspector is P/O'd at you, or thinks that you are trying to pull a fast one, I suspect that life will become much more difficult.  While its true that he can't just "lay-down-in-the-road" in front of your project, he can make you jump through so many hoops that it just isn't worth doing!!  A problem with which you seem to also be familiar!  <grin>

  One of the engineeers, of the two for this area, for NYSEG alternative energy, is a complete know-it-all-prick-of-the-first-water, who seems to believe that it is his mission in life to make it as hard as possible for anybody to get grid-tied.  The other engineer is much like my code inspector in that he tries to help people in any way that he can.  It seems that it is a giant game, if you get the first, undesireable engineer, to lay in the weeds and try to catch him in some sort of compromising position, so you can then ask NYSEG to assign the other engineer!  I have yet to be assigned an engineer, but I hope and pray that I don't get the first one!  The guy is such a loser that the code inspector even said something about him being an idiot!!!  <grin>

  That's my story and I'm sticking to it!  <smile>

  Thanx for your comments!!!  Pats on the back are appreciated as long as they are not too low and too hard and administered with a boot!

Regardz,

Wayne Stayton

[BioHazard]

 2) Not have to worry about asking things in a carefully worded non-chalant way so as to not arouse the suspicions of the powers that be with regard to control of your project.

LOL, you really hit the nail on the head there. For most of the questions I ask, on most other forums the only answer I'd get is "you can't do that" "that's not safe" "I don't like that idea" etc....Here at least instead of just saying "no" somebody usually has another suggestion....

Where else can you go and tell people you want to power your house with an old car engine and used motor oil instead of electricity even though you have all the power lines you need? People would consider you insane. Maybe we are....but what fun are normal people anyway?!

We'll see who's crazy once we have the first major power outage for days or weeks in a major population area....

[cognos]

There are all manner of legal disconnect switches for this purpose. Square D, Allen Bradley, ITE, etc. all make fused and non-fused knife-type disconnects (good for 10,000 amp surge protection across the knives) for isolating home services from the line, almost any amperage rating you can think of - 100 amp or 200 amp are common.
I think the Square D 3-pole - which will give you the capability to isolate your neutral on your home panel - is around $200. Safe, legal, enclosed. That's what I use top connect my generator to my home panel in an outage. I isolate my home service from the line at the meter -I have what's called a "farm service," there's lockable, breaker-protected service disconnect complete with a 50 amp breaker-connected plug-in for the generator, right at the pole.

I wouldn't want to be pulling/inserting 100 amp fuses to isolate my system. Open box, possibly live terminals... no thanks. Walk up to my disconnect, pull the lever, I actually lock the service out with a padlock to be doubly safe when I'm using my generator.

Just my opinion.

[WStayton]

cognos:

   I agree that a fuse isn't the ideal disconnect form the standpoint of safety and ease of use, but when I look at $45 vs $200, times two (one for incoming lines and one for generator), and then I look at my bank balance, I am willing to investigate how dangerous to use the fuses are when under load. 

  I agree, that if my further investigations indicates to me that what I want to do with the fuses can't be done, by me, safely, then its back to the knife switches.  I plain disconnect requires more investigation to determine if it will actually buy me any thing.  Since I am trying to protect the system from a massive EMP which would, I think, jump the 0.10" air gap in many disconnects, installing one of them is the equivalent of taking $200, digging a hole and burying it!  <grin>  It will do absolutely nothing to protect the system from a massive EMP event AND will have spent the $200 in the process - an absolute 100% lose-lose situation, no matter how easy it is to operate!  <smile>

  Oh, and for the record, I THINK I remember that they are projecting for a major EMP a pulse to be something like half a million volts!  I THINK that is going to pretty much eliminate anything that doesn't give you at least of couple inches of air gap.  Isn't the rule of thumb that a spark will jump something like 0.10" for each 100,000 volts on it?  So if the EMP pluse IS 500,000 volts, that gives me something like a safety factor of four for a knife switch that opens to a 2" air gap.

  My understanding was that the EMP was so dangerous precisely because it was consisted of so many volts and could thus jump many/most conventional disconnects.  Since there haven't been a lot of EMP events around since we have been able to measure the amps/volts generated by such events, it really is largely speculation for what to expect, but I would prefer to be "over protected" with a 2" air gap and not need all of it, than to be underprotected by a 0.10" air gap  and need a 0.50" air gap!  <smile>

  There was one such massive event in the mid 1800's, but since most everything was still gas lights and horses, it was sort of a non-event.   The same event today, would PROBABLY leave 95% of the spark ignition vehicles in the world lying dead with a "welded" computer control device, along with all the "modern" diesel engine vehicles that have computer controled high-pressure common-rail fuel systems.  Not to mention that it would also leave almost all of the step-down transformers which are part of the electrical grid, as smoking hulks, along with every other small coil, computer, etc., etc. that was attached to the grid, including my generator set-up, if I don't have it adequately islolated!             

While there have been times when I was messing with my pickup truck that I would have happily welded its computer back into the stone age, it probably wouldn't be a fullfilling experience on a wide spread basis!  <grin>

  Anyhow, thanx, everybody for your suggestions - I will, as previously stated, first investigate if a simple 100 amp cartridge fuse will work for me and proceed from there! My second line of defense, after the cartride fuse, will be a simple (and cheap! <grin>) knife switch.  Plan C to be formulated if/as/when necessary!

  Thanx, guys, for the input - all ideas are appreciated, because, even if they are something that I can't/won't use, it forces me to think about them and, just maybe, uncover something else about the problem that I have failed, yet again still more allready, to consider!

Regardz,

Wayne Stayton

[rcavictim]

Wayne,

The distance a voltage can spark across a gap depends on surface shape and smoothness and air pressure plus humidity, dust content, etc.  Many variables.  If AC then waveform plays a role too. Generally in a lab setting assuming dry air and large diameter spheres take about 50 kVDC per inch to jump.  Sharp pointy electrode shapes as in disconnects likely closer to 20 kV per inch.

If you want better EMP protection you should get a lightning protector on that mains from the street just prior to your disconnect.  You will need an excellent ground system for that to work properly.  It will cost money.  The idea being any HV pulse coming to the house from the mains will see a shorter path to earth ground and jump to there instead of trying to jump across the next opportunity in it's path which is your (hopefully open) disconnect.

[cognos]

I have a high-voltage lightning surge protector on the transformer that feeds my house. "Big Thorium resistor", the Ontario Hydro installer said, if I remember correctly. They put it on - no charge to me - all I did was ask about it, after my neighbor had a close strike, and it actually holed his natural gas supply line.

I also have a whole-house surge protector on my service. Plugs into a spare breaker space. Has a nice green winky light on it to help sooth my fears of line surges. Cost $200. I figure a simple .50¢ green winky light is probably as useful, given the likelihood of an EMP killing my "critical systems". But hey, again, Ontario Hydro paid for it.

If it was me, I'd just throw the main breaker, lock it out (comply with local electrical regs), and fire up the gennie. Anything powerful enough to blow backwards through an  open 200 amp breaker to fry your house is too "wild" a threat to plan for. I can't see planning for some kind of vanishingly rare, unpredictable, system-frying EMP - and not spending the cash to do it safely. I spent a lot of time in risk/benefit/cost analysis, and the numbers versus the perceived benefit - never mind the safety - don't make it worthwhile for me.

In my lifetime, there have been exactly 2 sun-related coronal mass ejections that caused grid problems in the area I live in. There was no problem at home, we lost power for a few hours the first time, seconds the second. No damage to anything at home or work, either time. The latest one did shut down the refinery I was working at. But the surge didn't do any damage to any equipment, we just fired it back up again.

But hey, I wish you luck. 

[WStayton]

rcavictim:

  Once again, you have come up with something that I hadn't thought about - this place is really worth what it costs, in slings and arrows and wonded prides! <grin>

  I HAD considered lightening protection, but I only thought about it on the photo-panel end of things.  NYSEG requires any grid connected solar array to have approved (UL?) lightening protection, I guess just to minimize/reduce the chances of feeding lightening pulses back into the line.

  I HAD NOT thought about the same thing on the other end of the system to protect against an EMP event!   My only concern, and I guess it is one that you have to live with, since I don't see ANY sort of a solution, is that if you have the "interrupter" open and you have the lightening protection, that you have pointed out is necessary, and a massive EMP comes along, will it be SOOOO big that it just jumps BOTH of the paths - the lightening protector AND the open "interupter"?  I guess there is really no way to know, unles you have an EMP (!), and it is, of course, better to have every reasonable available protection in place.

cognos:

  Ontario Power seems a lot more willing to do things FOR you (as opposed to TO you!  <grin>) than NYSEG is for us!  NESEG seems to act as though the only reason they are invoved in the whole solar program is because some law, somewhere, has told tham that to maintain their monoply, they have to permit solar systems to interconnect.  Since the controlling legislation did NOT say that they had to make it EASY to accomplish interconnection, they seem to have gone out of there way to make it not so . . .

  Of course, viewed from the other side of the coin, if I was in business, selling SOMETHING, I'm not sure how helpfull I would be to a competitor that the government told me I had to accomodate!  <grin>

  As for my worryiing about EMP's and other once in a million things - my motto is that I would much rather be a safe, protected PARANOID than an un-safe, un-protected NORMAL person!  Lets face it, if you go out and spend several thousands of dollars (even with all the expensive corners chisled off by a penny pincher - ME!) to do something that the power is willing to do for you, for free, to provide you with power for less money, you have to be a couple of dots off of the centerline!!!  I freely admitted that I am a bit (OK, a LOT!!) twisted, and, so long as my twisted-ness doesn't interfere with anybody else's life, liberty, and pursuit of happiness I intend to continue to be a little twisted!!!  "Normal" is SOO boring!!  <smile>

  That's ALL I have to say on that subject!!!  <grin>

  Again, thanks to all for their input - especially rcavictim!  It never ceases to amaze me how you sit quietly back and allow the "discussion" to flounder along in eighty differnet directions and then, calmly, stroll up and say "Did you think about . . . "!!!  Your insight and ability to pickout the kernal of corn in the pile of horsexxxx is enviable AND, at least by me, appreciated!

Regardz,

Wayne Stayton

[rcavictim]

Aw shuks Wayne.   Just doing my job.  Seems like the only work I am able to do is that for which I do not get paid.      I'm glad someone out there appreciates my perspective.  Thanx for the kind words.

[WStayton]

Hi, Guys!

  Well, while I was sitting reading the Xantrex manuals, sitting on a pile of fire wood, my Code Inspector drove up!!

  So, I basicaly just confessed all and asked him what he would approve.  He said that, basically if it said UL on the side of it, and wasn't otherwise inapproporiate - like a 20 amp fuse on an incoming line or something, he would approve it . . . BUT it would have to be inside of some sort of box or housing so that a casual observer couldn't just walk up and put his hand on 120/240.

  I then told him that I was concerned about being able to adequately operate cartridge fuses with a puller, so he strolled out to his truck, rooted around for a few minutes and pulled out a box with two 100 amp fuses in it and a set of disconnect pliers and said "Try these, and see what you think!"

  I wrestled with it for a while and did succeed in getting the fuses in and out a few times but I think that it would be a mistake to depend on that sytem for use on a day to day basis.  You have to squeeze the pliers VERY hard so that they don't slip off while you are inserting/removing the fuse and I just don't think I can depend on being able to do that on a day to day basis.  On a good day, everything would be fine, but if I'm having a bad day I might have problems and I am concerned that if I was wrestling around with the fuse holder and my hand slipped it might BECOME the fuse by getting across the poles of the holder!  Thanx, but No Thanx! <grin>

  So, I guess I'm back to a knife switch with a big handle!  My Inspector said that he has seen gang switches with a handle that is sort of a loop, so you could get your hand IN something and not be so concerned about it slipping off of something.  I THINK that will better suit my needs and condition, so that's what I am looking for - so far I haven't found one with a loop, but my inspector said he would see if he could come up with the name of the manufacturer, which I think would let me find one on the internet.

  Anyhow, progress IS being made - at least I was able to rule out an option without spending any money or electrocuting myself!!

  Oh, BTW, the manuals that came with the Xantrex XW6048 are pretty impressive.  The installation manual is about 100 pages, both sides and the operators manual is another 150 pages, both side and the configuration manual is about 25 fold out double pages that shows every way that you could possibly hook 1, 2 or three of these critters up!  You can even hook three of them up to give you three phase, if you are so inclined!  Of course at about $3,250 a pop, with shipping, that would make your three phase set up cost close to Ten grand!  I think I might strongly consider candles, kerosine lamps manual everything before I spent $10,000!

  Oh, and I discovered that if I want to "custom" program the unit and not except the factory defalts I need another device called an "XW System Control Panel".  It sort of sucks that you need this box just to program the machine and after that it just a fancy display, but I think I have to have it, otherwise the factory setting for battery bank is something like 500 amp hrs - so all of the stuff that tells you how much battery you have left, based on usage, will be wrong!  Also, the device compares the battery voltage with what it "thinks" you should have at the state of charge that it thinks you have, based on the battery capacity you have set in and if it desn't aggree within a few percent, you have a continuous fault light.  Since my battery bank is going to be 360 amp-hrs, it will a) always be optimistic about how much battery I have left and b) always, except at full charge, be displaying a fault light because I will have less voltage than it "thinks" I ought to have!  So, I guess a "XW System Control Panel" is in my future - I just hope it isn't TOO expensive!!!

  After looking at all the pretty pictures, my Inspector asked me why I didn't spring for Xantrex's proprietary distribution panel.  When I explained to him that I couldn't see where it would do anything for me that the conventional 100 amp panel from Lowes with a couple of 60 amp, instead of 100 amp breakers, would do, for a quarter of the cost.  He grinned and said I might make an electrician yet!

  So, that's my story and I'm sticking to it!

Regardz,

Wayne Stayton

[rcavictim]

Sounds like your inspector is a decent fellow, not some petty tyrant like so many are that they give the rest a bad name.

Different field entirely but for example, did you know that 99% of lawyers give the rest a bad name?   

[DanG]

http://thomashardware.ecrater.com/p/9520532/100a-four-pole-double-throw

That is a totally unknown quality piece linked as an example  EDIT: zero UL listing so its objet d'art in your application.

I do know that, for example, in Central America countries there is a large market for basic devices like knife switches but the quality is a huge unknown.

I saw a US made nicer unit with spring-loaded snap-open contact-tail followers.. for around $700 new...  vital for opening under any load.

[WStayton]

rcavictim:

   Along the same line . . . Whats the differance between a dead lawyer in the road and a dead skunk in the road??  Skid marks before the skunk!   <grin>

  Okay, that's enough of THAT!  <smile>


DanG:

  You had to go and ruin it by putting the "not UL approved" line in there, didn't you?  <grin>

   Let's see . . . I could scan in the Ul approval stamp and then print it out on a piece of mylar and then, VERY carefully cut out the letters & numbers, with an Exacto knife, and then put on the disconnect and spray paint over it and, PRESTO, UL approved!!!  Lets see, the fine for producing counterfeit goods is only $10,000 and/or 3 years in the pokey, per occurance,  . . . maybe that isn't such a hot idea after all!!

  But really, if it had a UL stamp on it, would ANYBODY ever investigate to see if the stamp was legitimate?  I'm not advocating doing it, but just thinking here - you just casually look and if the UL is there, you assume that is good to go.  I wonder how much of the stuff that is coming in from China has taken this route???

  That, BTW, is EXACTLY what I need, so if anybody knows were there is a UL approved one, PLEASE speak up!

Thanx for the input guys - everything is appreciated - even the lawyer jokes - what good are they if you can't make fun of them?   <grin>

Regardz,

Wayne Stayton