Author Topic: Circuit Breakers  (Read 24455 times)

Halfnuts

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Re: Circuit Breakers
« Reply #30 on: March 26, 2006, 02:20:09 AM »
Geez, Jimmer, that article opened my eyes.  Wonder if they've ever polled their neighbors across the Channel.   :-\

Halfnuts

jimmer

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Re: Circuit Breakers
« Reply #31 on: March 26, 2006, 04:26:18 AM »
Let's don't even go there!

Viva la listers!

jim

trigzy

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Re: Circuit Breakers
« Reply #32 on: March 26, 2006, 09:29:29 AM »
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
Power Anand 24/2, Brushless 20kW, some other antique iron.
Vendor of AVR's, Small Clones of Yanmar Diesel and Honda Gasoline Engines

sb118

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Re: Circuit Breakers
« Reply #33 on: March 26, 2006, 05:34:08 PM »
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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(hey, it's a sunday, that's the best i can do  :P)
First love - 1975 Lister SR1, gone to a better place (running a saw bench actually ;))

True love - unknown vintage CS6/1 with SOM flywheels

linkie to the project so far --- http://jestersltd.com/pics/index.php

Lister owners do it at 650 strokes a minute ;)

rpg52

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Re: Circuit Breakers
« Reply #34 on: March 26, 2006, 08:20:07 PM »
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
PS Listeroid 6/1, 5 kW ST, Detroit Diesel 3-71, Belsaw sawmill, 12 kW ST head, '71 GMC 3/4 T, '79 GMC 1T, '59 IH T-340

GuyFawkes

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Re: Circuit Breakers
« Reply #35 on: March 27, 2006, 12:22:09 AM »
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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Current status - project / standby, Fuel, good old pump diesel.

rpg52

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Re: Circuit Breakers
« Reply #36 on: March 27, 2006, 12:46:45 AM »
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
PS Listeroid 6/1, 5 kW ST, Detroit Diesel 3-71, Belsaw sawmill, 12 kW ST head, '71 GMC 3/4 T, '79 GMC 1T, '59 IH T-340

trigzy

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Re: Circuit Breakers
« Reply #37 on: March 27, 2006, 01:40:37 AM »
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
Power Anand 24/2, Brushless 20kW, some other antique iron.
Vendor of AVR's, Small Clones of Yanmar Diesel and Honda Gasoline Engines

Doug

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Re: Circuit Breakers
« Reply #38 on: March 27, 2006, 02:40:11 AM »
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

 

rpg52

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Re: Circuit Breakers
« Reply #39 on: March 28, 2006, 01:08:17 AM »
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
PS Listeroid 6/1, 5 kW ST, Detroit Diesel 3-71, Belsaw sawmill, 12 kW ST head, '71 GMC 3/4 T, '79 GMC 1T, '59 IH T-340

trigzy

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Re: Circuit Breakers
« Reply #40 on: March 28, 2006, 01:20:34 AM »
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
Power Anand 24/2, Brushless 20kW, some other antique iron.
Vendor of AVR's, Small Clones of Yanmar Diesel and Honda Gasoline Engines

Doug

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Re: Circuit Breakers
« Reply #41 on: March 28, 2006, 02:07:49 AM »
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.
« Last Edit: March 28, 2006, 02:41:32 AM by Doug »

rpg52

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Re: Circuit Breakers
« Reply #42 on: March 28, 2006, 04:59:04 AM »
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
PS Listeroid 6/1, 5 kW ST, Detroit Diesel 3-71, Belsaw sawmill, 12 kW ST head, '71 GMC 3/4 T, '79 GMC 1T, '59 IH T-340

Doug

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Re: Circuit Breakers
« Reply #43 on: March 28, 2006, 07:55:08 PM »
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

rpg52

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Re: Circuit Breakers
« Reply #44 on: March 29, 2006, 02:54:35 AM »
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
PS Listeroid 6/1, 5 kW ST, Detroit Diesel 3-71, Belsaw sawmill, 12 kW ST head, '71 GMC 3/4 T, '79 GMC 1T, '59 IH T-340