kirk key install aka what city workers do

[rockwithjason]

I haven't posted a build thread in a long time. i had a cool job today and I was in the mood so here I am.

for those of you who don't know, I am a utility service electrician for one of the water/waste water systems here in town. yeah i am one of those city workers everyone loves to ***** about.

Disclaimer: i am an electrician by trade (17 years in the IBEW) and an all around general handy dude. I am NOT a machinist. what i don't know about machine work could almost fit in the grand freakin canyon and i am sure that the REAL machinists will get a laugh at my expense ( i ain't scared so go ahead ) I will write this in plain english. those of you with advanced know how may want to skip to the good stuff. ok here we go.

 

[WVBrady]

I didn't see anything. Is this a joke?

 

[Steevo]

What happens in Vegas . . . . stays in Vegas.

 

[slip knot]

Dont see any kirk key install here. But I did have have Square D/ Group Schnieder out last week to install a couple of 2000 amp mains with a kirk key set up. You weren't in South Tx last week ??

You guys install and my guys opertate it. Been in municipal operations for the past 17 yrs.

 

[csargents1546]

Jason, I think you have been out in the heat to much lately

 

[Stuart in MN]

I'm an EE and I design water and wastewater treatment plants...I'm pretty familiar with Kirk Keys.

 

[FreddiFiche]

I'm an EE and I design water and wastewater treatment plants...I'm pretty familiar with Kirk Keys.

I'll raise you with a.....I'm an EE, used to design controls for water and wastewater treatment plants, and now work for the company that manufactures the majority of the controllers used in those plants. (and I know what a Kirk Key interlock is too <Double - smile>)

 

[Jack Olsen]

Whereas I write fiction for a living and can only imagine that we're talking about some kind of beer bottle opener.

 

[admranger]

I'll raise you with a.....I'm an EE, used to design controls for water and wastewater treatment plants, and now work for the company that manufactures the majority of the controllers used in those plants. (and I know what a Kirk Key interlock is too <Double - smile>)

I'll re-raise you...my name is Kirk. Push those chips here please dealer.

 

[rockwithjason]

alrighty then, since the internet hates me tonight i am now on my third attempt to add to this thread. but hey that's life.

our water system uses pump stations to pump water uphill to holding tanks. we use gravity to pressurize the lines leading to your house. we don't generally use pumps to pressurize water mains because it's too expensive. we do have one area like that but it's a total charlie foxtrot. anyway today i was working in an medium sized pump station with six 50hp pumps and two one million gallon tanks

 

[rockwithjason]

the building has an 800 amp utility service fed from a pad mount transformer outside. the utility main goes underground to the MCC (motor control center) mounted on the pump skid inside. the mcc has horizontal and vertical bus bars that feed various buckets that in turn feed the individual circuits such as pumps, heaters and so on

 

[koditten]

I know what your talking about.

Kirk

 

[rockwithjason]

in this station as in most of our stations we have a bucket with a breaker (in this case a 400a breaker) connected to a box on the outside of the building. the box contains terminals that allow us to connect a trailer mounted generator to power the mcc in case of an outage. we have two generators in our stable, 350 kw and a 750 kw. we could use either of these or a rental.

there is a problem with this set up tho. what if some chuckle head connects a generator while the utility power is still on? or what if we are running along on the generator and the power is restored to our utility feed? there are two main ways to deal with this, one way is to use a transfer switch. the transfer switch allows only one source of power to be in use at the mcc at a time. in our situation transfer switches often don't have high enough short circuit current ratings to be used and they are one more thing to maintain. the other method is to use a mechanical interlock commonly known as a kirk key.

in the pic we can see the generator connection bucket with the brass kirk key in place. the kirk key assembly has a pin that slides horizontally into a hole in a disc shaped cam mounted to the side of the handle.

 

[rockwithjason]

the kirk key system in this case will consist of two lock assemblies and one key. the key is captive in the locks when the pin is retracted. this means that one power source or the other can be connected to the mcc BUT NOT BOTH.

more on kirk keys if you care
http://kirkkey.com/default.aspx?Page=SD%20Series%20Interlocks.

the problem is that the installing contractor ordered the gear incorrectly and no kirk key provision was built into the main breaker bucket. i spoke with the factory and they pretty much told me to go pound sand and that no parts or kits are available to the aftermarket so i will have to make my own.

i but welded the metal tab to the mechanism a few months ago during a scheduled shut down, sorry no pics of that.

 

[rockwithjason]

the most direct approach to fixing this issue is to copy what the factory has already done so after an hour or two of careful measuring and brain grinding i rounded up all the goodies to git r done.

the cam is made from aluminum bar stock i found in the junk bin. the diameter is just a hair large at 1.615 in where i estimated i need 1.5 in but this is not tight tolerance work. if i am within 1/8 in or so i will be good.

 

[rockwithjason]

off to the handy dandy enco mill. no this is where real machinists will probably gnash their teeth because again i am all self taught with the help of many hours of video.

for this job i will have to use what i have available to me which is limited. i am allowed to make small purchases of tools without too much hassle but i have to be careful of what i spend or the bosses go nuts.

i ordered some really cool vee blocks from penn tool for this. i have twenty bucks in the set of two and they have four different vee slot sizes. there are probably better and more accurate ways to do this but the cast iron vee blocks lay flat enough on the mill vise that it will do for this job

 

[rockwithjason]

now i have to find the center of the bar stock. for this i will use a coaxial indicator. this tool is great for centering up on inside or outside diameters. i have used it with great results for a number of things. i mount it in a collet and install it in the mill.

I install a curved feeler and get the work lined up as close as i can by eye. then i take the belts off of the drive and turn it by hand until i am within the sweep of the indicator. i reinstall the belts for the lowest speed. the needle on the indicator will sweep back and forth until you get the work set up on center. the closer the sweep the closer you are to center.

i adjust the x axis by turning the feed handle. the needle sweep will decrease as you come closer to center so i feed until i pass thru center and start to see the needle sweep open up again. then i back off just a touch. now i do the same with the y axis. i have to repeat this four or five times until i am within 0.0005 in of center. i turn on the digital display and set it for zero. again there are a hundred ways to do this and i am sure there are better ways than i used but this is what i had available to me

 

[rockwithjason]

now i use a center drill to drill a guide hole into the bar stock. i will have to raise the mill head and I will lose my center when i do. the guide hole will allow me to easily get back on center within the tolerance of this job. i would have rather have used a collet for this also but the quill doesn't have enough travel so i settled for a chuck.

 

[rockwithjason]

time to get the end mill and face the bar stock. this is the side people will see so i want it to be as pretty as i can make it. i use a 1/2 in mill with four flutes on this operation

 

[rockchucker]

Still listening...

 

[rockwithjason]

more to come tomorrow.

 

[rockwithjason]

Jason, I think you have been out in the heat to much lately

i wish! it's 50 deg f here and i am freezin!

 

[rockwithjason]

I'm an EE and I design water and wastewater treatment plants...I'm pretty familiar with Kirk Keys.

I'll raise you with a.....I'm an EE, used to design controls for water and wastewater treatment plants, and now work for the company that manufactures the majority of the controllers used in those plants. (and I know what a Kirk Key interlock is too )

i am probably just boring you guys, you will want to skip ahead.

 

[rockwithjason]

Dont see any kirk key install here. But I did have have Square D/ Group Schnieder out last week to install a couple of 2000 amp mains with a kirk key set up. You weren't in South Tx last week ??

You guys install and my guys opertate it. Been in municipal operations for the past 17 yrs.

nope, no south texas for me. they keep me at home where they can keep and eye on me.

 

[rockwithjason]

I didn't see anything. Is this a joke?

no jokes here. i was trying to post this while listening to a dry and boring lecture on filler metals in my TIG class. i would type a few paragraphs and hit the submit button only to find out that the post had been flushed so i had to wait until i got home to get going.

 

[rockwithjason]

Whereas I write fiction for a living and can only imagine that we're talking about some kind of beer bottle opener.

you would

 

[rockwithjason]

What happens in Vegas . . . . stays in Vegas.

what happens in vegas goes straight to face book my friend

 

[Chaz]

I'm finding it really hard to give a **** about this ......

 

[archirelic]

I'm finding it really hard to give a **** about this ......

Thanks for your input.

 

[FreddiFiche]

i am probably just boring you guys, you will want to skip ahead.

Nawww, I was just having a little fun until you got past your technical difficulties. I always appreciate were 1 key give you the ability to switch 2000amps at will, and makes me think about how arc fault protection is changing this....

Justin

 

[K'ledgeBldr]

Whereas I write fiction for a living and can only imagine that we're talking about some kind of beer bottle opener.

You mean "churchkey"?

 

[offroadsteve]

And here I was thinking this had something to do with Star Trek...

 

[csp]

Does this thread have a point somewhere?

 

[rockwithjason]

ok, back from dinner and ready to finish this off. where was I? oh yeah, time to drill the relief hole for the locking pin. the offset from center of the bar stock to the center of the relief hole is 0.583 in so i roll the x axis 0.583. it doesn't matter what side of center i drill it because the mounting holes will have to be drilled in the field anyway. i start with a center drill to mark and pilot the hole then i use a drill that is about 1/8 oversize to allow some slop for the pin to slide in. the key here is to take your time. if you push it the drill can literally push right out the side of the work piece and break off and you will probably lose some skin in the process.

 

[rockwithjason]

l slice off a section of the barstock about 5/8 in thick and this will be my cam for the handle. i hold the cam in place on the bucket handle and mark for the two mounting holes. i use transfer punches to mark the centers of the holes and drill 1/4 in holes for the mounting bolts. i chose a drill bit just a hair smaller than the heads of the bolts for my counter bore. this will allow the 1/4 bolt heads to be below the surface profile of the can where they will not interfere with the lock. the holes are just small enough for the corners of the bolt heads to cut into the sides of the counter bore. this will allow me to tighten them without tools. a few whacks with a brass hammer and we are good to go.

 

[rockwithjason]

these show the cam in place and the stainless mounting bolts.

 

[rockwithjason]

time to mock up the kirk key on the tab i welded to the mechanism earlier. i use vise grip clamps to hold the kirk key in place while working the mechanism to get the fit i need. once i like how it works i transfer punch two 3/8 mounting holes and drill. top it off with some stainless hardware and the kirk key interlock is in place. now the breaker can only be closed if the key is in place and the lock pin is retracted.

 

[rockwithjason]

pump stations are generally pretty humid so exposed steel doesn't last long. i happen to have some friends in low places that mixed up some factory correct paint and loaded it into spray cans for me. a little tape off and a few shots of allen bradley gray will do nicely. i am not really worried about the decals because they will all be replaced.

 

[rockwithjason]

the door for this bucket was never cut for a kirk key so i have to cut it. the cut off wheel and a file makes a decent looking result, not perfect but decent. there was one little area that hit on the corner of the cam but a few passes with the file took care of that. the whole gear will be washed with vinegar to get rid of those white calcium deposits and new decals and signage will be added. all done!

 

[ranger302]

Looks great, but you might want to use tamper proof bolts to hold the lock on. I have seen some crazy things with people tring to defeet Kirk locks.