# Square D model 4 MCC manual



## Wirenuting (Sep 12, 2010)

Does anyone have a link to the PDF manual for a Model 4 Square D MCC?

Wanting to pull a bucket and don’t see any latch or jacking screw. 
I’m going to replace the buckets disconnect knife actuator, #HU100-3MC. One phase don’t disconnect and we had a new one manufactured new. 

Took a peek and the buss looks to be round stock. None of the other smaller buckets seem to have the ability to be jacked out. 

Has anyone heard of the buss clips having issues after being pulled?

It’s a 2 speed, size 3 starter.


This is a just b left by others for me to stumble into. 
Yes I’ll LOTO it out.


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## Wirenuting (Sep 12, 2010)

Disconnect


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## MDShunk (Jan 7, 2007)

I have no idea about that one, but there are models out there that have 3/8" headed bolts in the sides in the wireway section on each side.


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## Wirenuting (Sep 12, 2010)

MDShunk said:


> I have no idea about that one, but there are models out there that have 3/8" headed bolts in the sides in the wireway section on each side.


The wireway is stuffed and I didn’t see the bolts. 
My biggest worry is the buss clips and if they will retain when I attempt to reinsert. 

This is a job that an apprentice looked at a few months ago. Ordered new 2 speed starter and knife blades. Now he’s gone. 
By the time I looked at it parts were on their way and there is nothing wrong with the starter. 

I just had the boss come look, he’s an AC guy and is clueless. 
I told him this was a perfect time to have installed a freq drive. 
Told him it’s sketchy if I’ll get the MCC back up if things go south. 

The 30 min job just turned in to a WTF.. 
Glad we own the gear and not a customer. We can let it ride for awhile.


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## Forge Boyz (Nov 7, 2014)

I've worked in one of them already. I think the one I pulled had flat head screws in the back of the bucket holding it in, then just grab ahold and pull it our

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## Wirenuting (Sep 12, 2010)

Forge Boyz said:


> I've worked in one of them already. I think the one I pulled had flat head screws in the back of the bucket holding it in, then just grab ahold and pull it our
> 
> Sent from my Moto Z (2) using Tapatalk


Thanks, 

Round buss bars?
With shaped clips holding them to the buss?


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## Forge Boyz (Nov 7, 2014)

I believe it had round buss and clips. It's been a little while. 

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## Forge Boyz (Nov 7, 2014)

Here are pictures of a size 3 reversing starter I found on River City industrial's website.














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## gpop (May 14, 2018)

Just looking at the pics it looks like the flat head screw top left and bottom right. 
If you have lost a leg i would power the bank down before trying to pull it. Theres a small chance that the wire has broke free from the clip.


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## Wirenuting (Sep 12, 2010)

Forge Boyz said:


> Here are pictures of a size 3 reversing starter I found on River City industrial's website.
> View attachment 127662
> View attachment 127664
> 
> ...


Oh man thank you very much. 
That's what I thought I would see..

My concern is those clips being weakened after 35ish years of hard starting. 
The thermal cycling might have weakened them and getting a tight fit back would be sketchy. 

This one would be a great candidate for a freq drive.. I have an empty bucket next to this one.


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## Wirenuting (Sep 12, 2010)

@;


gpop said:


> Just looking at the pics it looks like the flat head screw top left and bottom right.
> If you have lost a leg i would power the bank down before trying to pull it. Theres a small chance that the wire has broke free from the clip.


This one had lost a leg several months ago. An apprentice ordered a new disconnect unit as one blade no longer will engage when you use the handle. He used his screwdriver to push it in.. It was his first time seeing an MCC and he was alone. 
He ordered a new part and since the contractors sounded bad,, he ordered a new 2 speed starting unit with a back plane.. (The starters were fine) 
Now he's gone and it was handed off to me.. 


I don't mind pulling some buckets from some brands of MCC's hot. But this model 4 seems different. No way I would pull it hot.. 

I just have this feeling on this one that something is different.
Ever see that movie "Final Destination"?


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## gpop (May 14, 2018)

You can probably still buy the back clip block if you are that worried about it


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## gpop (May 14, 2018)

Wirenuting said:


> @;
> 
> 
> gpop said:
> ...



If i was just replacing the disconnect and i could power down the bank and lock it out. I would probably leave the bucket in place and just replace the disconnect


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## Wirenuting (Sep 12, 2010)

gpop said:


> If i was just replacing the disconnect and i could power down the bank and lock it out. I would probably leave the bucket in place and just replace the disconnect


That was my first plan when we couldn’t cancel the order for the starters. 
But now that they came in, the boss wanted them, with the new back plane also installed. The new plane doesn’t leave any room for the accessories that are in place. 
After looking at it today I had him come and look. Told him it’s his choice as to what he wanted me to do. He don’t know what he’s looking at as he’s an AC guy. 
Figured it’s best to wait till a slower time and then pull it if needed. 
We might just add a new drive and abandon this bucket. The building can’t be without the AHU that it feeds for a long time.


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## Wirenuting (Sep 12, 2010)

gpop said:


> You can probably still buy the back clip block if you are that worried about it


Yes, Square D said they will gladly remanufacture one for us. 
The disconnect finger block was $3400 and took 8 weeks.


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## paulengr (Oct 8, 2017)

Try Southland Electric in Burlington, NC, or Quality Switchgear. They probably have the parts in stock.

Other than the extra labor the VFD itself would be about 30-40% cheaper even for the higher priced Altivar 630/939s compared to that contact block price, maybe a little more if you need dv/dt filtering or constant HP. And save all that money when it comes time to replace the motor with a standard one instead of the higher priced special order two speed.


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## colorado_electrician (Jun 11, 2018)

I've had problems with the clips many times before. 
We always kept a couple on the shelf in our shop for out customers that still used them. Then when we swapped them out we would send them into a company that would rebuild them for us.
Can't remember the name of the company that rebuilt them but if memory serves me it was out of Minnesota. I'll see if I can track them down...


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