# Removing bucket from AB MCC and replacing with disconnect switch



## Veteran Sparky (Apr 21, 2021)

Why not put a 200a breaker in the bucket? or is bucket damaged...hence the DO NOT USE piece of tape.


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## Breakfasteatre (Sep 8, 2009)

I could do that too, good idea


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## CMP (Oct 30, 2019)

There might be a good reason it is tagged DO NOT USE, I would suggest that you look into the bus connection first and see why the tag is there...And power the board down before you go looking for a surprise.


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## Breakfasteatre (Sep 8, 2009)

The inside was effectively stripped except for the disconnect mechanism.


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## Breakfasteatre (Sep 8, 2009)

CMP said:


> There might be a good reason it is tagged DO NOT USE, I would suggest that you look into the bus connection first and see why the tag is there...And power the board down before you go looking for a surprise.


i would need to pull new wiring into it either way.

I will be putting a power logger on the bus so i will inspect it at that point


im wondering how kosher it would be to re-use the bucket enclosure, installing a 200a breaker inside.


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## Wirenuting (Sep 12, 2010)

Veteran Sparky said:


> or is bucket damaged...hence the DO NOT USE piece of tape.


That looks like the pump is out of service and they left the wires there for “Future” use.

That’s the bucket I would use if the glycol pump is never being used again. Pull that run out.


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## Wirenuting (Sep 12, 2010)

Breakfasteatre said:


> im wondering how kosher it would be to re-use the bucket enclosure, installing a 200a breaker inside.


We do it all the time. but we insure that the breaker can be operated with the door closed.


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## CMP (Oct 30, 2019)

What size is the bucket disconnect, should be labeled on the side of it. If it were big enough, I would get the factory trailing fuse block kit. If it's only a 100A switch, I think your into tapping the bus, for something adequate. The bus taps to the existing switch may not be large enough.


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## Breakfasteatre (Sep 8, 2009)

CMP said:


> What size is the bucket disconnect, should be labeled on the side of it. If it were big enough, I would get the factory trailing fuse block kit. If it's only a 100A switch, I think your into tapping the bus, for something adequate. The bus taps to the existing switch may not be large enough.


considering the size of it, it was surprisingly only rated for 30 or 40a inside on the little nameplate


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## joe-nwt (Mar 28, 2019)

Breakfasteatre said:


> considering the size of it, it was surprisingly only rated for 30 or 40a inside on the little nameplate


Some buckets that size had more than one contactor inside them. Maybe wye/delta setup for that pump?


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## Breakfasteatre (Sep 8, 2009)




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## CMP (Oct 30, 2019)

Look on the side of the disconnect, likely only a 100A for a size 2 bucket.


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## just the cowboy (Sep 4, 2013)

I have seen the tap rule applied and come off of the buss bars with a fused disconnect, it don't look like they are going to expand it.
That said I don't think I would add anything large to that old thing.

Cowboy


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## CMP (Oct 30, 2019)

Breakfasteatre said:


> View attachment 169359


I did some basic checking on that Size 2 part number. It was a two speed size 2 combination starter. In these size applications they typically came with a 60 or sometimes 100A disconnect switch and a trailing fuse block with 60 or100A fuse holders.

To get a 200A disconnect, you would need a size 4 bucket. So you will need to tap the bus and provide your own fused disconnect or breaker.

Here is a CUT SHEET for the current combination starter and sizing for your comparison.


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## paulengr (Oct 8, 2017)

Just contact an aftermarket company like Southland in Burlington, NC. Get a bucket that works as-is.

If there is no such thing remove the splice plate cover. The bus is already punched with holes so you can just attach lugs there. Cut a hole in the cover and attach an LB and put your disconnect down at a convenient level or wherever you want to go to. This lets you access the full horizontal bus capacity.

If you call AB to buy new here is a little trick. Buy an MLO section and a section with the bucket you want plus fill it up with anything else you want. This will be MUCH cheaper. MCC buckets from the manufacturer are 300-500% higher priced when you buy just buckets. If you order a main breaker or main lugs then you get the “new MCC” price. On one smaller bucket it’s not worth it but on bigger ones or say two size 3s you save money.


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## Almost Retired (Sep 14, 2021)

keep in mind that the size of the stabs on the back of the bucket will be rated for what the bucket is rated for
if you put a 200A breaker in a 60A bucket with 60A stabs to the buss you will have trouble

as paul said go directly to the buss with bolt on lugs

as you said make sure the capacity is available on the buss and particularly the feeder to the MCC


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## Breakfasteatre (Sep 8, 2009)

Almost Retired said:


> keep in mind that the size of the stabs on the back of the bucket will be rated for what the bucket is rated for
> if you put a 200A breaker in a 60A bucket with 60A stabs to the buss you will have trouble
> 
> as paul said go directly to the buss with bolt on lugs
> ...


In terms of calling it bucket, thats probably a mis-speak. It doesn't plug on to the bus on this MCC. Each seperate motor controller has a nipple into the back MCC enclosure and the disconnect is connected with wires. Unfortunately I didnt take a larger picture of the insides. 

I think instead of trying to retrofit anything, I will quote to install a 200a fuses disconnect off of it.


appreciate all of the responses, I have not worked with these old MCCs much.


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## micromind (Aug 11, 2007)

If the 200 amp power feed is a panel, is there a neutral nearby?


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## Breakfasteatre (Sep 8, 2009)

The 200a power feed is for an existing splitter that does not need a neutral. They want to re-jig some things, and the current feed for the splitter is coming from the 1st floor (this is on the second), and they want to free some power up down there for new equipment


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## paulengr (Oct 8, 2017)

Breakfasteatre said:


> In terms of calling it bucket, thats probably a mis-speak. It doesn't plug on to the bus on this MCC. Each seperate motor controller has a nipple into the back MCC enclosure and the disconnect is connected with wires. Unfortunately I didnt take a larger picture of the insides.
> 
> I think instead of trying to retrofit anything, I will quote to install a 200a fuses disconnect off of it.
> 
> ...


Sure you aren’t missing something here?

The vertical bus is quite a bit less than horizontal as far as amp rating. Further, plug in are only offered up to a certain amp rating which is often half the vertical bus rating. So you could have a 600 A horizontal, 300 A vertical, and buckets only up to 75 A as an example. After that point you can still order sections with “buckets” that are really just doors and the breaker/disconnect either bolts directly to the bus or has jumpers with clips of some kind. It is a “bucket” in name only. That is how “VFD” sections, main breaker sections, “lighting panels”, and even “PLC” sections are made.

My suspicion is that only the “big breaker bucket” is made this way. The regular size 0/1/2 starters will be plug in, if someone actually bought an entire MCC of nothing but bolted in stuff they got ripped off! A simple iLine panelboard would be vastly cheaper and more reliable.

I forgot the brand of the only truly screwy “MCC” I have seen with non-removable “buckets”. It was a true doozy. To begin with it was back-to-back but only 20” deep in total. Confused yet? So each “bucket” was made so there was only one actual vertical bus that was shared so that each side plugged into the same vertical bus. So in reality each “bucket” was only about 7” deep with an inch for the doors and about 3-4” for the screwy bus assembly. So again…MCC in name only,


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## SWDweller (Dec 9, 2020)

Eaton makes replacement buckets as well. The configuration you want might take a week or two.
I have used the Eaton buckets in the past. If you are good at ordering all of the stuff you need they build pretty much to your specs. Pull out the old and replace with the new. These days and not knowing the history of the MCC you probably should take an outage.


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## paulengr (Oct 8, 2017)

SWDweller said:


> Eaton makes replacement buckets as well. The configuration you want might take a week or two.
> I have used the Eaton buckets in the past. If you are good at ordering all of the stuff you need they build pretty much to your specs. Pull out the old and replace with the new. These days and not knowing the history of the MCC you probably should take an outage.


How would you List such a thing?

You can’t put Eaton buckets in an AB MCC. You can use HMCPs but that’s another story.


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## SWDweller (Dec 9, 2020)

these are NOT Eaton Buckets, they are made by the aftermarket group. 




https://www.eaton.com/us/en-us/catalog/low-voltage-power-distribution-controls-systems/mcc-aftermarket.htmt




I agree with you about the listings. Even when I worked for them I never understood the concept of building all this stuff for aftermarket uses. At one time Eaton made replacement SQD QO breakers. 
I never did get a handle on that concept.


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## JRaef (Mar 23, 2009)

I’ve got bad news for you. That is NOT an “MCC”, it is an ancient predecessor to MCCs called a Bulletin 797 _Modular_ Control Center. A-B stopped selling those in the late 1970s. There were no “buckets” like in an MCC, it was just a system of bolting together sone separate combo starters and a wiring trough connecting the power. There are no parts available any longer. So your idea of just quoting a separate 200A disconnect is actually the only possible solution.



https://rockwellautomation-test.custhelp.com/ci/fattach/get/36693/1268322952


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## Breakfasteatre (Sep 8, 2009)

JRaef said:


> I’ve got bad news for you. That is NOT an “MCC”, it is an ancient predecessor to MCCs called a Bulletin 797 _Modular_ Control Center. A-B stopped selling those in the late 1970s. There were no “buckets” like in an MCC, it was just a system of bolting together sone separate combo starters and a wiring trough connecting the power. There are no parts available any longer. So your idea of just quoting a separate 200A disconnect is actually the only possible solution.
> 
> 
> 
> https://rockwellautomation-test.custhelp.com/ci/fattach/get/36693/1268322952


So that does coincide with what I saw, where the "bucket" was connected to the bus with wiring through a chase nipple. 

Awesome document, thank you for posting that


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## SWDweller (Dec 9, 2020)

Thanks for the link, I learned something new today, thank you


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## JRaef (Mar 23, 2009)

I’m not surprised that there are still sone of these out there. They were based on the old 709 starters that were obsoleted in I think 1979 when I was working for a steel mill. Those 709 starters were hell for stout. 

USS didn’t want any obsolete devices so we had to swap them all out for the new 509 starters back then, it was a ton of work when you think of how many starters there are in a steel mill. Most of our stuff was originally built out during WWII for the war effort, so those Mod Centers were how it was configured, since MCCs as we know them now didn’t exist yet. The problem for us was that the new 509 based combo starters were smaller, so the first couple of centers looked kind of crappy after swapping everything out. They changed to just buying MCCs at that point and it was actually a lot easier to install them.


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## Wavelet8 (Jan 11, 2014)

If you do plan to go with the fused safety switch hung on the side of the cabinet with lugs attached to the main bus bars, please look at the amp rating for the entire mcc unit. If the amp availability is too high on the supply bus bars, you may be required to install an oversized disconnect on the side of the mcc cabinet so that it’s listed the required conductor size wire you will be forced to utilize for connecting the buss bars to the fused disconnect. You may need 200 amps but you may be fired to install a 400 amp with smaller fuses per the tap rules.


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## 460 Delta (May 9, 2018)

JRaef said:


> I’m not surprised that there are still sone of these out there. They were based on the old 709 starters that were obsoleted in I think 1979 when I was working for a steel mill. Those 709 starters were hell for stout.
> 
> USS didn’t want any obsolete devices so we had to swap them all out for the new 509 starters back then, it was a ton of work when you think of how many starters there are in a steel mill. Most of our stuff was originally built out during WWII for the war effort, so those Mod Centers were how it was configured, since MCCs as we know them now didn’t exist yet. The problem for us was that the new 509 based combo starters were smaller, so the first couple of centers looked kind of crappy after swapping everything out. They changed to just buying MCCs at that point and it was actually a lot easier to install them.


Where I worked at before had several plants and a block plant built back in the mid 70’s. One plant had a CH Unitrol MCC, and a couple had Arrow Hart MCC’s with ITE breakers and 700 series AB starters. These all had pull out interchangeable buckets. The Unitrol was better built than the Arrow Hart. 
Allen Bradley must have been really dragging behind times.


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