Lister Engine Forum
Lister Engines => Lister Based Generators => Topic started by: guest23 on March 23, 2006, 12:16:47 PM
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I have a 6/1 with a 5kw generator which is mounted on a trailer. It does not have any circtui protection. Has anyone put breakers on theirs? The generator is currently wired for 115 volts. Should I leave it at that or wire it for 230 volts?
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I would go out and buy a fused disconnect and some time delay fuses. You'll have to decide for yourself of you want a 120 or 240 volt connection. Fused switches are a little cheaper and unlike CBs they aren't as sensitive to vibration. Fuses are cheap and reliable they only fail one way (they blow obviously) where as CBs tend to be more expensive and more sensitive to heat and vibration.
I have an industrial 30 amp fused disconnect for my genset in the making for the generator itself and small laod center that will be mounted inside that house. This is an Ontario rule to have a local disconect, but when you think about it its not a bad idea for any remote aplication where your load and your generator are not within line of sight and easy reach.
Doug
Don't forget grounding!!!!!!!
You will need to ground common wire in your set to make the system safe. Again code requirements may differ in your state or province but a good rule of thumb is a #6 green wire joined at the white common wire in your disconnect and ground bus to a suitabe plate electrode or ground rod with no splices or joints.
Over current protection, grounding and bonding are the most important steps you will take with the project
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You should make provisions for circuit breakers unless you like fires, electrocution, general mayhem and so on...
The 120V vs ~220V question is more complicated.
If you wire it so that you have a single 120V output, you can crank the entire 3kw (contiuous load) or the entire 5kw (peak load) into a single big load, eg a decent table saw that runs on 120V or a 120V water pump, or some combination. The other advantage is that you don't have to worry about balancing the loads on two separate circuits (or "legs"). The big drawback is that you can't run ANYTHING on 220V.
The other option is to wire it for 120/230 with two separate "legs". You get 120V on each leg, and 230V between the two legs since they run opposite phase. The big disadvantage is that each circuit or leg will only be able to push 1500 watts continuous or 2,500 watts peak, and you have to pay attention to balancing the loads so they are approximately equal between the two legs.
On the other hand, the fact that you have "oversized" the generator for the horsepower you have, allows you to cheat a little. In reality, you could probably push 2,500 watts through one leg of the generator, but the gen won't specially like it and will probably make funny noises since it's unbalanced that way.
Hope that helps!
troy
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Hi,
I'm with Doug on this one - if it's mounted on a trailer, or anything that vibrates excessivley, go with the fuses. Breakers offer alot of advantages with differnt trip curves, resetability etc. and if they can be isolated from the vibration, I would prefer them.
Grounding / Bonding systems like this is a major issue that even most residental/industrial electricians wont understand fully, so you should check with your local authority, and/or someone who installs generators for a living. I wont even start to cover it becuase of all the "ifs" and "whatever you do don't ........"'s that vary in each circumstance.
Now; for my safety warning. I'll amplify the scenario to make it more obvious what can happen:
Lets say you have a 10kW Listeriod, and you've hooked it up to a 20kW gen head. So you go ahead and put fuses on it rated for the 20kW output of your alternator. Here's where you run into problems: You dead-short the output, but because your listeroid only makes 10kW, the power out of your gen-head wont go much above 10kW. Let's even say it goes up to 15kW in a dead short, that is still not enough to to blow your fuses, and your wiring/load burns up and starts a fire.
So, always make sure that whatever fuse/breaker size you choose, that it's appropriate for the generator as well as the prime mover, and that the generator and the prime mover together can provide enough energy to trip the protection in a reasonable amount of time.
Of course, with a 6HP engine (~4.5kw) and a 5kW gen head, this isn't much of an issue, but I thought I'd mention it for those with bigger setups.
Steve
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Looks like I will go with the fuse idea. Would 40 amps be about right? I will keep it wired for 115 volts to keep the load balanced. I will put in a ground rod with some sort of clamp that can be easily removed so I can move the generator if needed. Here in the country we don't wory about inspectors or codes, but I do not want to cut corners to make anything unsafe.
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Looks like I will go with the fuse idea. Would 40 amps be about right? I will keep it wired for 115 volts to keep the load balanced. I will put in a ground rod with some sort of clamp that can be easily removed so I can move the generator if needed. Here in the country we don't wory about inspectors or codes, but I do not want to cut corners to make anything unsafe.
Well if you want insurance coverage you better get it inspected
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40A is 4800watts, just about right.
Steve
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The subjects of Bonding and Grounding are two separate issues. Grounding I believe is the connection of
the generator to mother earth. Bonding is a connection between one of the AC outputs to ground making it
the neutral. Bonding is only done at the main service panel of the feed entrance on a home. Only one bonding point
should exist. When feeding a home with the generator, the genie should be left floating & not bonded (but still grounded). In an
application that does not have a service panel, bonding should take place in the fuse box on the generator.
At least that is how our inspectors like to see it. Your local white hats may be different. Play safe!
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Being as I'm using my generator for construction power, sounds like I should mount a service panel on a post and run a power cord to a fused outlet on the generator. Then do the bonding and grounding from that panel.
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List,
For generators CSA & UL (accepted in Canada and the US) standards recognize some of these basic criteria
Portable Generators: (Construction etc etc, not likely to be feeding a building or existing electrical service)
Neutral & Ground should be bonded inside generator (or the panel attached to it) The user should not be easliy able to remove this bond, (ie. you shouldn't have to attach anything to the generator to make this bond work) Should be clearly labeled: "NEUTRAL BONDED TO FRAME GROUND" If you later wish to use a transfer switch with this type of setup, it will have to switch the neutral as well as the hot leg(s). (Therefore a 3 pole switch for 120/240 services) Generator should have a ground lug for attaching a grounding plate/rod/etc.
Stationary Generators: (Or generators that will primarily be connected through transfer switches)
Neutral & Ground should not be bonded inside the generator, and should obtain a connection from the panel the generator is feeding. Should be clearly labeled "NEUTRAL FLOATING" Transfer switches need only switch the hot leg(s), so only 2 poles for a 120/240 service. Generator should have a ground lug on it as well, but NOTHING SHOULD BE CONNECTED if it is plugged in to a transfer switch. No wiring change required when used as a portable generator, and though it is "not unsafe" it should be noted that the "margin of safety is reduced" when using this type of generator in a standalone configuration. When used as stand-alone, a ground plate/rod should be attached.
Tom, for your setup, you should bond the neutral & ground inside the generator, and attach the grounding plate/rod directly to the generator. If you still wish to have the panel away from the generator, you can still use your power cord, and your grounds will remain in tact if someone pulls out your extension cord, or if the connections in the cord/ends/receptacles become intermittent.
(How to tell I've set up waaaay too many of these, and paid waaaay to much money to our inspection authority......)
Steve
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Thanks Steve,
Beyond the standard construction items I'm also running a 120V well pump with my rig. I'm rather sure the inspector is going to want to see this wired correctly before I "use" it. Also my thought was that if I positioned everything right that I could reuse the ground rod for the temp panel later for the house.
The generator is now located about 50' from where the house is going to go. The plan is to run a 30amp RV power cord from the panel to the generator during use. Right now I am running un-fused which is a no, no so I think I'll add a 30 A fuse box on the generator with an hour meter, RV outlet and standard 120V receptacle.
Think the inspector will be happy with that?
And thanks again!!!
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The other angle to consider is wire size. Your fuse/breaker really needs to be sized so you cannot overload the ampacity of the wire. Generator/engine size may come into play as well (and as pointed out by others), because they must be capable of producing enough amps to trip your device.
Good luck, have fun, and tweak the nose of the inspector for me. Always wanted to do that but was chicken.
Finest regards,
troy
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Troy,
Thanks for mentioning the wire size, I just always assume that people know that. Everyone should keep in mind wire sizes change based on open-air and in-conduit runs, temporary and constant loads, and the type and temperature rating of the wire, so make sure you consult an appropriate table for your application.
Tom,
Not sure about your particular area, but the inspectors here are pretty good in that they know you are going to liven something up before it's passed inspection. Most of the work I do is on a "rennovation" basis, ie. the power system is already on & installed, so I cant say that I've livened up a building while under construction. Inspectors will usually consult with you over the phone, so that you are "ready" for them. Ask what they want to see, what they dont want.... They dont want to fail you, and they dont want to make lots of repeat visits. Clean wiring techniques, and new equipment (not some rusty old panel you "dug up") really puts inspectors at ease. A wiring diagram, showing bonding locations, ground loactions, and where your protective devices are makes the inspection process easier.
No major issues with the wiring you have described, but keep in mind, in most places, the generator has to be approved by UL or CSA or similar before it can be used. You may need to arrange for a "field inspection" of your generator. I have to run now, but I'll start a new thread detailing my experience with field inspecting generators.
Steve
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Yea, I think the inspector is going to have a spaz when he sees my generator. I want it to at least appear that I know what I'm doing. ;)
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Thanks everyone for the great posts,
Just when I think I've almost got it figured out, you guys expose my ignorance to myself. So, I'm building a sawmill, remote from grid power, and so dependant on generated electricity. My main mover is a Detroit Diesel 3-71, about 75+ hp., that I have driving a 12 Kw ST head. I have the power generated going through a 50 amp sub-panel, with a 50 amp main, a double 20 amp 220 volt circuit, and two 20 amp 110 volt circuits.
Because of the noise generated by the Detroit, I want to hook my Listeriod and 5 Kw ST head into the same panel. I'm obviously not going to try to drive the 220 v circuit, but would like to be able to use the same 110 v. wiring to distribute the power. The 220 circuit will drive a 5 hp planer and a 3 hp table saw, plus I'm using it currently to drive my 220 v. arc welder used in fabricating the mill foundation. The 110 v. load will primarily be lights and possibly a 1 hp. motor on a bandsaw.
So, here is my question, I'll be installing a 60 amp transfer switch to move back and forth from the 12 Kw head to the 5 Kw head. Should I also install a ~30 amp fused panel on the circuit from the Listeroid 5 Kw head to the transfer switch? Both generators share the same ground, a length of #4 copper wire in the concrete foundation. Thanks for any and all opinions. BTW, it won't be inspected, but I still want to do it safetly.
Ray
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It's always easier to make a recommendation if you can see the layout and poke around in there...
Despite that, I'll throw out an option, and other more experienced hands can go from there.
What I would do is install a subpanel with breaker(s) that drives your 120V circuit(s). "Upstream" from that subpanel, I would put the generator transfer switch, which is just a glorified A/B box. Your two sources of electricity feed into this transfer switch, one from your present main panel powered by the Detroit, the other from your Lister generator. The feed from the main panel needs a breaker appropriately sized to protect the wire from the main panel to the gen switch, and the feed from the Lister generator also needs breaker or fuse protection for the wire from the generator to the gen switch panel. This setup prevents you from ever electrifiying the 220 stuff with the Lister or from ever accidentally connecting the two generators which would be BAD.
Comments??
Finest regards,
troy
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don't re-invent the wheel
the genuine lister start-o-matics addressed all these problems
http://www.surfbaud.co.uk/Lister/
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don't re-invent the wheel
the genuine lister start-o-matics addressed all these problems
http://www.surfbaud.co.uk/Lister/
We're not reinventing the wheel. Our "road" is a little bit different, so we need a different "wheel" than you do. Our voltage here is 120/240, and we have special requirements for bonding and grounding. Genuine Listers wouldn't be able to address either issue, and eletrical inspectors here would never approve such a unit without some serious overhauls. Although UL & CSA, and US & Canadian elctrical standards in general are accepted almost all over the world, the reverse certainly isn't true. Inspectors over here will just laugh at more European electrical ratings, standards and codes.
I like troys idea, even though I had to read through it a couple times. I drew this little diagram of what troy was explaining:
DETROIT {~}----> [120/240 PANEL] ---------->>---------- [X-FER SWITCH]-->>----->[120V PANEL]
| | |
| ^ |
| | |
| {~} |
240V and BIG LOADS LISTER SMALL 120 V LOADS
It is simple, and offers the least posbility for screw-ups. We COULD put a transfer switch before the 120/240V panel, but it will need to have a higher rating, and then there are some "ifs and buts" about hooking up only 120V from the Lister. I the above scenario, anything you want to run off the lister would have to be on the 120V panel (including the battery charger for your detroit) and your bigger loads would go on the 120/240V panel. My {~} indicates a fuse or breaker right at the generators, and I'm assuming that your 120/240V panel will have a main breaker and a breaker feeding the X-fer switch. The small 120V panel wouldn't require it's own main breaker in this scenario, but I'd use a breaker on the lister as it's easier to reset.
If you're interested in this setup, we can talk about grounding and bonding in more detail. Whatever you do, make sure that you only have one ground. (Ie. dont put in a ground rod in one spot, and another one 50' away and ground half the building with one, and the other half with another, or even tie them together. I'll say it again: ONLY ONE GROUND) Of course, you can put multiple plates/rods down in the same area, and infact that is recommended. But they should all be attached with the same wire.
Steve
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Thanks so much everyone.
Trigzy, your proposed solution would actually be a lot easier than what I was thinking of doing. The existing panel is already working well, and it would be much easier to route the wiring through another panel. I was initially thinking of cutting the circuit from the Detroit, installing the transfer switch, then routing the Lister into that.
I'll do some photos in a week or so, after the weather relents a bit. Thanks again!
Ray
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Ray,
It was actually troys idea, I just made the pretty picture. Do you have a transfer switch yet? Are the neutral/ground bonded together in your Detroit? If we set this up right, you might not even need a "transfer switch", we might be able to find a large relay or "3-way" switch and save you some $$$.
Steve
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Although UL & CSA, and US & Canadian elctrical standards in general are accepted almost all over the world, the reverse certainly isn't true. Inspectors over here will just laugh at more European electrical ratings, standards and codes.
you really are a grade a idiot.
USAian electrical standards are just sooooooooo high, we poor europeans could never possibly hope to meet them.
come over to the UK some time, if you can find ANY domestic mains socket anywhere in any house that doesn't have a proper earth pin that HAS to be inserted before the live and neutral pins _can_ be inserted then I'll give you 100,000 of your petro dollars.
or perhaps you can advise us why 110 VAC domestic is so much safer than 220 VAC
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Dear Guy,
It's not really a question of better, it's a question of different.
Good luck and have fun!
troy
ps, Hey Trigzy, thanks for the diagram, much easier...
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Trigzy, that was a grade A answer. Thank you
Guy, go fuck yourself to tears. At times you almost make sense, and then you go off like some demented old sot. You really should allow 24 hours after you quit drinking before you post here. BTW, our standard is not "110 VAC domestic", it is 120/240V, as trigzy wrote.
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you really are a grade a idiot.
Personal attacks are unnecessary.
USAian electrical standards are just sooooooooo high, we poor europeans could never possibly hope to meet them.
come over to the UK some time, if you can find ANY domestic mains socket anywhere in any house that doesn't have a proper earth pin that HAS to be inserted before the live and neutral pins _can_ be inserted then I'll give you 100,000 of your petro dollars.
or perhaps you can advise us why 110 VAC domestic is so much safer than 220 VAC
Your wiring standards are fine, but the ratings applied on generators, appliances, breakers, wire etc are must less stringent. Hence the multitudes of items available with CE etc. marks, but few available with UL marks, and the large cost spread between them.
Our plugs have grounds that have to be plugged in first as well, and I'm not about to justify our reverse compatibility with old standards. Europe did have this (and other similar saftey systems implemented faster than North America, I'll give you that. Early North American wiring makes me shake my head.
Who said 120 was safer? Anyone arguing the safety of any voltage is COMPLETELY missing the point, the safety should come from the design that the user can never touch a conductor, not that one voltage is "safer" than another to get electrocuted by. Even Edison and Westinghouse made that mistake. The whole 120/240 thing is a really stupid setup, and quite regrettable, but you cant tell everyone to throw out thier old stuff and change millions of houses worth of wiring.
Steve
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you really are a grade a idiot.
USAian electrical standards are just sooooooooo high, we poor europeans could never possibly hope to meet them.
Guy, Guy, we all know this isn't really about electricity, is it?
Now sit down, have a cup of tea, and let me sing you a little song by the legendary Johnny Horton:
In 1814 we took a little trip
Along with Colonel Jackson down the mighty Mississip.
We took a little bacon and we took a little beans
And we caught the bloody British in the town of New Orleans.
[Chorus:]
We fired our guns and the British kept a'comin.
There wasn't nigh as many as there was a while ago.
We fired once more and they began to runnin' on
Down the Mississippi to the Gulf of Mexico.
We looked down the river and we see'd the British come.
And there must have been a hundred of'em beatin' on the drum.
They stepped so high and they made the bugles ring.
We stood by our cotton bales and didn't say a thing.
[Chorus]
Old Hickory said we could take 'em by surprise
If we didn't fire our muskets 'til we looked 'em in the eye
We held our fire 'til we see'd their faces well.
Then we opened up with squirrel guns and really gave 'em ... well
[Chorus]
Yeah, they ran through the briars and they ran through the brambles
And they ran through the bushes where a rabbit couldn't go.
They ran so fast that the hounds couldn't catch 'em
Down the Mississippi to the Gulf of Mexico.**
We fired our cannon 'til the barrel melted down.
So we grabbed an alligator and we fought another round.
We filled his head with cannon balls, and powdered his behind
And when we touched the powder off, the gator lost his mind.
[Chorus]
Yeah, they ran through the briars and they ran through the brambles
And they ran through the bushes where a rabbit couldn't go.
They ran so fast that the hounds couldn't catch 'em
Down the Mississippi to the Gulf of Mexico.
Now - don't you feel better?
Love and kisses
Russell
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http://news.bbc.co.uk/2/hi/uk_news/england/4831180.stm
jolly good show old bean!
jim
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From Guy Fawkes
"USAian electrical standards are just sooooooooo high, we poor Europeans could never possibly hope to meet them.
perhaps you can advise us why 110 VAC domestic is so much safer than 220 VAC"
Well, some standards are different don't get your knickers in a twist. I have built equipment destine for markets from China to the EU and there is a good reason for differences in local codes. Climate, safety standards, available fault current on the power system and in many cases simply the way people prefer to have things wired. I don't personally feel there is a right or wrong set of standards most are very close at least in intent. Me I like European 240/380 low voltage 50Hz 3 phase power systems and wish we had them here instead of the Edison 3 wire but the die has been cast....
And from Steve
Grounding / Bonding systems like this is a major issue that even most residential/industrial electricians wont understand fully
That doesn't truly reflect the reality of the modern trades man in Ontario. Not only do I understand them, I build them. And you should be quite leery of any electrician who doesn't. 40 hours a week I build and baby sit a distributed power system the size of small city with voltages ranging from 120v to 69 kV that is constantly evolving growing to adapt to the changing requirements for safety and to provide power for production as the mine I work in grows and becomes deeper ( And now that 110 year old mine is 7810 feet deep with at least 60 miles of drifts raises and ramps and shafts ) and for the sake of my friends I sure hope I understand what I am doing.
Talk is cheap, do you want to find out the right way to do things?
Call your local hydro inspector ask him some intelligent questions and buy a code book.
Then get the bloody thing inspected and you'll sleep sound.
Fusing vs. CBs....
I deal with both kinds, I like fuses they're simple safe and proven. If your blowing a lot of fuses or tripping a lot of brakers that means something is wrong or overloaded and it shouldn't happen in the first place.
Do you want to know why I like fuses? They work only once and then you replace them no questions or doubts.
They don't blow up in your face like I've had happen to me when after years of resetting and neglect they finally fail.
Now I can hear Steve chomping at the bit when I say fuses don't blow up because they can if you choose the wrong one for your ap. But then this comes back to knowing what you are doing. All things in electrical must be engineered to a standard that reflects the conditions of there use. Some might think this is beyond the understanding of a humble trades man in mine but I have an inter provincial ticket and 5 cog silver ring on my finger that says I can do a fault calculations and size fuses and CBs and understand their characteristics.
Currently I am working on writing a new standard for the inspection and upgrades of our small 500-1333 kVA portable 13.8 Kv portable substations to try and improve reliability and safety because I have found problems with the cables that were made to a US standard not CSA that are showing signs of insulation failure from corona damage and the neutral resistor monitoring system (part of system that limits fault current incase of a short to ground in our ground fault protection systems). Safety and reliability are an on going process that I am proud to be part of in co-operation with ESA, CSA and the authors M-421 electrical systems of the mining act.
My goal is increase my "ass time" in chair in the 7000 electrical shop an not "wrench time" fixing failures or worse writing reports on accidents that hurt my friends.
Lets get back to thread now and talk about the safest, cheapest, and simplest wire one of these blooding things without slinging mud at standards, those who write them or the people that turn them into reality.
Doug
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http://news.bbc.co.uk/2/hi/uk_news/england/4831180.stm
jolly good show old bean!
jim
I don#t wear knickers or underpants.
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you really are a grade a idiot.
Personal attacks are unnecessary.
no. nor is ill informed bigotry, which is what your post was.
take some time and learn a little about the subject (eg european electrical standards) before pronouncing them as inferior and worthy of nothing more than laughter from superior american/canadian elctricians and you'll find generally in life you'll get a hell of a lot less people making what you deem to be personal attacks.
you as a person are probably a great bloke, but you are talking shit, too bad if you don't like being called on it.
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Gentlemen, and I am using the term in the best possible way, lets move on, nobodies system is the best, as posted, all systems take into account local problems, rules and customs. Everyone has the best intend, no system is better, they just are.
Cut the personnal attacks, it takes away from the general comradship and love of the listers.
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Geez, Jimmer, that article opened my eyes. Wonder if they've ever polled their neighbors across the Channel. :-\
Halfnuts
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Let's don't even go there!
Viva la listers!
jim
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Doug,
Sorry, the strokes from my brush may have been a little wide. Not everyone works on such diverse systems as yourself, and I'd bet that there are residental electricians that haven't looked at fault calculations in quite a while. I based my statements on a conversation I had with an inspector down here who says that they try and inspect every generator installation (even from the authorized contractors), as they see mistakes (cable types & bonding), unapproved equipment (gen & x-fer switch), and a lot of back-feed attempts.
We're also in a different area, there are a lot of "fly-by-night" contractors without licenses etc, and enough bad stories for seasons of "Holmes on Homes" Things may be different in other areas......
No arguments from me on your discussion about fuses... My only other thought on the Fuse/CB issue is that if your generator (say 5kW) is a lot less than the amount of power you normally have available (say 24kw, 100A @ 120/240), and you are using a full-transfer setup, you (or your family members) might become a bit "greedy" and try and draw more power than your generator can produce. If you're not around, it's a lot easier and safer explaining to a lay-man how to reset the breaker than it is how to replace the fuses.
Speaking of switches/breakers/fuses blowing up, I've never seen one in person, but have seen some cool videos. I was also taught to always have face & body turned away from any switch being operated.
Cant find the one of the small panel blowing up, but this is cool too:
http://video.google.com/videoplay?docid=4468957986746104671
Steve
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Cant find the one of the small panel blowing up, but this is cool too:
http://video.google.com/videoplay?docid=4468957986746104671
Steve
Shocking ;D
(hey, it's a sunday, that's the best i can do :P)
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Not wanting to get in the middle of any cross-the-Atlantic tiff, I have posted a couple photos of my existing generator/prime mover. To reiterate: Detroit Diesel 3-71, with 12 kw ST gen head. I plan to mount my Listeroid directly behind it and feed the power from the 5 kw ST head into the same circuits. The circuits have yet to be placed, waiting for construction of the enclosing building to be built. Here are the photos:
http://listerengine.com/coppermine/displayimage.php?album=lastup&cat=10038&pos=0
http://listerengine.com/coppermine/displayimage.php?album=57&pos=1
Thanks,
Ray
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Your biggest problem, because it WILL happen sooner or later, is connecting both running generators to each other out of phase.
Beyond that you need a separate system for each genny, tailored to that genny, and the output of those can go to a distro board, with its own set of protective devices.
However, sooner or later you or someone else will interconnect both running gennies, and then you'll probably lose everything.
What matey said about fuses was spot on, but breakers with a reset delay are useful tools, as are neons.
I'll say it again, sooner or later someone will interconnect both, saw it done last month on a boat with a distro panel that made it "impossible" to do this, which even had dual circuits running around the hull, didn't stop someone wiring the two circuits together by mistake about 40 feet down the hull from the engine room.
The other thing you want to watch out for is fuel, especially with the very high return rate of a detroit, unless you have two totally separate bunker systems you'll lose both gennies to any contamination.
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So, the suggestion was to run the two 240 v circuits into a transfer switch = the equivalent of a double pole, double throw switch. The 120v from the 12 kw head would come in one side, the 120v from the Listeroid 5 kw head from the other side.
A circuit from the transfer switch would then enter a second panel with breakers, and then out to the 120v loads. I guess nothing would stop someone from altering that and mucking it up, but it seems like it would be difficult. The 120v power from the 12 kw head would be going through two sets of circuit breakers, but the two generators would share the same 120v circuits through the transfer switch. It would seem like the only potential way to connect the two generators would be from the 240v circuit to the 120v circuits. Could happen I guess, but it seems unlikely.
Ray
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Ray,
Sorry - maybe it's just the wording that confuses me... Are you still talking about the system that I "drew"?? If so, the transfer switch only needs to be a single pole double throw, because it is only switching one hot line for the 120V loads. Properly set up once, there would be no way to cross-connect unless someone showed up with an extension cord with two male ends on it.
Steve
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Too all:
Tommorrow evening when I go on shift I will photogragh a few of the transfer switches we use at the International Nickel Company for our back up generators. Once a year we bring in several large diesels to provide back up power while I do my inspections of the main CBs and switch gear. This should give people a better idea of how things should be connected, grounded and protected. And if all goes well and I haver more "ass time" than "wrench time" in the works. I'll try and take some photos of the how the wiring methods and equipment have changed since the 1930s to present.
Steve I'm not offended, but I have been fighting perceptions like that from people in planning and general engineering for quite some time and I'm quick to growl . Thankfuly people are begining to change and listen and this extends well beyond just my little tap off the infinite bus.
Considering the potential for injury and property damage those of us in the know need to make an effort to explain and educate on safe wiring pratices. Once I have some good photos we should start a new thread to explain the theory behind all of this so every one here has a clear understanding.
Doug
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Anyone else having problems posting replys?
Steve, I had already bought a transfer switch before I asked the question. Could return it I suppose, but it should work fine switching both the hot and neutral from the main panel?
Doug, the more info on safe wiring the better. Spinning iron and electricity make me nervous, especially when they go together.
Ray
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In this case, I'd be a bigger fan of NOT switching the neutrals if possible, but that is certainly an option. I'd be curious to see which method Doug prefers.....
How many pole is you transfer swich, 2 or 3? Is it a manual unit?
Steve
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My personal feeling is one should completely isolate a generator thats on stand by and switch the neutral. But this requires a second ground system.
As far as switching is concerned I feel that Priorety loads should be moved to a sub panel with a neutral switching transfer switch.
My reasoning is this if you have a power failure the trouble on the load side of your meter may cause other unexpect problems that you might want to be isolated from. Perhaps there is a downed pole or blown transformer what ever the case may be. I know I have a good ground here in my house possibly as good or better than the pole transformer across the road because of a high water table and this might cause me some concern in a lighting strike or other freak power problem.
Second I have a limmited amount of power to run a home in an emergency so realy only the things I need should be loading the system this would include furnace, water heater, AC, fridge, sump pump, lighting ect. I don't need the oven, sauna, hot tub, outdoor lighting and garage ect. But then this is easy for me to say because I have a sub panel and its quite easy for me to move the loads on this.
Next thing we need to consider is what kind of transfer device do I need?
Most here will not likely have a stand by unit that with remote start, so an automatic transfer isan't realy needed. But I have a couple of 50 amp contactors on hand so I might add this later. Right now my choice is a simple three pole square D 30 Amp disc with 7 Hp rating. I'll post pictures of what I have in mind after I'm home from work, its a 3 phase 600 volt unit not fused. Im not going to say this is the best unit on the market but its on hand, easy to buy and cheaper that some of the larger units I'm going to show you.
Ray:
You want to see some spining Iron? Lets see if I can figure out how to post a picture of the "big guy" the 7000 hp hoist motor and skip drive from #9
http://www.putfile.com/dougwp
I never actualy looked at these before....
Quality sucks, but what you are looking at is a GE 56.3 rpm 7000 hp 800 Vdc motor and hoisting drum, A 1980s twin GE silpac 6 phase drive master and slave drive (the big grey cabnets) and some cool looking vintage 1960s mechanical speed controls, the hoistman's dog house and the 69 kV main service incoming where my job begins.
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Steve,
I don't yet actually have it in my hands yet, from what I understand it is a 60 amp 2 pole. Should get it later this week. Doug, that is some big equipment. Only thing I've been around that is of that scale was a tour I took of a hydroelectric plant inside a reservoir dam. I was told the vertical shaft weighed 80 tons and was spinning at 200 rpm. Kind of hard for me to conceive of the engineering involved in putting it in place and adjusting it. The Listeroid is a little closer to my capabilities. :)
Ray
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You can't see it in the picture but to the left is a second hoist with an ABB syncronous motor rated at 4000hp.
We call it the ride to hell 7120 feet of straight down ....
Its verry hard too see in the pictures but the drum hoist and all its parts were cast in GB and painted a lovely hunter green like some other forever machine we know of....
Now they weld everything, not that any one has tried to build a convetional hoist this size since #9 was built in 1968. The main thing here is it was buil to last like few things new are made anymore. And its a joy to work on because with the exception of the Silpac drive it lets you know when its unhappy with clear and obvious signs well in advance of a serious brake down because so much fudge factor went into the slide rule engineering, its overbuilt.
There's nothing wrong with a two pole switch, I assume you sized it to your 60 amp house service right?
Doug
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Doug,
This system is off-line, nothing but generator electricity within 100 meters or so. It seemed easier than trenching that 100 m. with the cable/conduit etc. 60 amp happened to be the size available - plenty for the 12 kw gen head, or so I was told. May regret it someday I suppose.
Ray
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My personal feeling is one should completely isolate a generator thats on stand by and switch the neutral. But this requires a second ground system.
Sorry - this is going to be a bunch of boring stuff about grounding/bonding and how it applies to the Canadian electrical code.
Doug,
I dont see why you would need a new ground, you can use the same system ground, you would just have to bond the neutral & ground in the Lister.... I dont see how you would add a second ground without viloating that new ground only allowed for "separately dervied systems"rule.
Rule of thumb as I was taught in a "standard" system:
Transfer switch:
Switched neutral: Neutral Bonded in Generator (Generator obtains ground from system - bond for loads obtained from gen when operating from it)
Non-Switched Neutral: Neutral Floating Generator (Generator obtains ground & neutral when cord is plugged in - bonding obtained from main panel)
Steve
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Your right Steve your not supposed to do this "in a nut shell" in a home with one service but this is a case of two buildings and an isolated power system with an interconnection.
You ground once and bond everything else. But when you "Bond" the common in the ST head at its source
Fourth retype now.....
And I've read section 10 about 4 times now and I keep changing my mind.
I'm probably in the wrong here but I need to talk to an inspector regarding rule 10-208, 10-206 and 10-700.....
Sid. If your reading this whats your take?
Five....
Yup the same rules should aply, I do this at work and I should be able at home pending the ESA take.
Doug
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Doug,
I thought if I just waited to respond long enough that all the code book references would disappear..... :-[
I just memorized the "usual" requirements for "normal" systems, and the simple "don't dos" list. I dont want to complicate things - I'm sure there are all sorts of things you "can" do....... But I dont want any goofy orange outlets in my house ;)
Steve
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No you bring up a good point.....
I can do this in an industrial setting doesn't mean its smart to try and do it like this at home.
I must admit the big 4/0 ground from the grid to the colon of the mine has spoiled me.
What was I saying about knowing what I'm doing with grounding and bonding lol????
Goofy is right.
Other ideas on the goofy list that didn't make it into print were:
Neutral resitors grounding system based on a Startco 325 relay....
Industrial lighting arrestors from a 4160 substation....
Solas transformer power conditioning....
Remote start and transfer wired into my sump pump UPS ( itself a refugee from a pack up power suply for closing brakers )
Doug
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Doug,
Whatever you decide to do...... let us know. The sump pump backup is always good if flooding is a possiblility. I was measuring ground on poles one day (using an interesting device constructed for that purpose) H1 allows a maximum of 25ohms for a good ground. Needless to say - I dont think I found even one that was under 75ohms......except in the transfomer station. It's amazing what a couple thousand square feet of fence buried can do for your ground....
That same week, I was laughing at the guy working in the Transformer station when the Aug '03 blackout occured. You should have seen the look on his face when I told him I was going home and to "have fun closing that 500kV switch BY HAND after you run down the station batteries" I've never seen lights and computers turned off so fast in my life.
Steve
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Nope I'm going to bond the neutral at the head on the line side of the disconnect like you said, like I should and run 3 pole transfer switch between the main and sub panel.
Ya priming a braker by hand can be a real bear.
I had to do the same a few months back on a 6900 braker because the universal motor fried when a couple of S&C fuses blew in what was suposed to be a ty-switch (that strangely had fuses in it not on the print GRRRRR).
So I spent 20 minuts ratcheting the springs and closed it only to find the SOB rattled hummed and did a funny little dance when when the remaining phase came to life some silly poop head (not exact words used at the time) didn't update the prints. Of course its pannic time too because the pumps that keep the mine dry won't run without power. Now those upper pumps are running but the deep pumps won't start and I found some creative stress cones in a 13.8 switch that couldn't take abuse now I have an S&C doing a funny little dance between me and the door of a tiny electrical vault. 18 hours I spent priming brakers, changing fuses and soiling myself LOL.
You know we're(by that I mean the power dept with me standing there looking like a dummy) suposed to check the ground grid and our 4/0 magic cable but I can't say I've ever seen it done. Thank god we use neutral grounding resistors on our 13.8 and down to limmit fault current. On the other hand you pray those protection systems will work but its always in the back of your mind there are brakers no one ever remebers seeing trip and a lot of the old stuff has no test.
I've been lucky some of this stuff is real old and abused.
Other fun and games with medium voltage:
"Why is everyone dragging their feet in here?"
Spud wrench impaling a 13.8 mine armour cable in the shaft is it live?????
35 year old cables subjected to hipot tests and returned to service then I get to close the switch
Personal fav standing ankle deep in water in flooding 4160 vault trying to get the pumps running ( I was green, stupid and did what I was told ). That was lots of laughs I had this realy attractive young cage tender with me and she says is there anything I can do? So said I stand on this plastic chair outside the switch room and If I fry call for help she stayed there scared poopless untill I fired up the pumps
Any one know how to use these new 3M splice kits ?
Hey these hot gloves expired last year.....
Phone call to No.1 sub " Can you tell me how to do a station guaratee? "
How long has that light that tells you we have a ground on that ungrounded delta been flickering?
What is this goo were standing in next to the Askeral filled transformer?
13.8 unshielded cable.... exists???
Its a learning curve, stops when you retire....
Doug
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Interesting stuff Doug..... but I will point out one thing you may have misread....
"closing that 500kV switch BY HAND" isn't "Ya priming a braker by hand can be a real bear."
I'm sure priming those big breakers really sucks, but I'm talking a gaint 3phase, 500kV knife switch, OPEN AIR, basically 3 15 foot long bars. Normally opened/closed electrically with no load and preferably no potential......
When operated manually, there is a 2 foot diameter wheel on the side of the switch. They "trained" me to operate it.......
"Whatever you do, whatever happens, just keep turning"
I guess the arc starts to form about 7 feet away if you are closing the thing, and take about 10 feet of open air when opening.....
And that's just to magnetize the transformer in the station...........now that's a little scary.
Aparently there have been "incidents" when the switchs bars dont meet the jaws..... and the whole damn thing welds itsellf half shut...
Delta stuff in commerical applications makes me a bit nervous....... And what is "Askeral"??
Steve
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Oh my by hand realy means by hand better him than me.....
Askeral was a type of PBC oil used in the old days. I'll be pumping it out of 40 year old junk as we replace them with dry types for the next 2 years. Nice O/T job suit up like the X-files suck the oil into drums and drag the corps up to surface.
Yup, I saw an ungrounded delta ossilate back about 16 years ago. No real hint of trouble untill ac motor drivesed started tripping on "DC bus over volt" and someone noticed the light out. Trouble is we couldn't shut down the transformer because the foundry furnaces were loaded. Voltage spikes were aproaching 800 Volts The ABB drives starting dying without a whimper. The Yasakwa stuff shut down before it failed but we needed them running to run the cranes to tap the furnaces.
Glad I was just the crane man, they lynched they guy responsible for the fault in the compressor plant
Doug