VFD and MCC question

[Erik Dienberg]

Does anybody if there is a manufacturer that makes a VFD that would fit into
an existing MCC bucket spot?

Erik

 

[SQLit]

Does anybody if there is a manufacturer that makes a VFD that would fit into
an existing MCC bucket spot?

Erik

Lots of manufactures make small VFD's as retro fits to most manufactures
buckets. If you have a bucket with a size 00 and a CPT (control power
transformer) your probably in trouble. The CPT is almost as big as the
starter.

Find beg or borrow an YES book from Cutler-Hammer-Eaton Electrical. The book
is amazing for older Westinghouse and CH products. EE also has a book on
retro fits In the GE and SQ Dog lines.

I would be careful, modifying new equipment, it can lead to voiding any
warranties left.
Do you really need a VFD? Would a soft start work? EE makes some pretty
small soft starts, I have installed them into existing buckets lots of
times. Personally most people use a VFD for the soft start. Not because the
load is variable. I worked at a place where we had over 700 VFD's. Less than
30 were really a variable load. Most started ramped up to 100 percent and
stayed there. What a waste of dollars.

I would suggest that you look at the type of MCC you have and open up the
wiring doors, do you have any spare space top or bottom? You might and not
know it. Then you can re-arrange the buckets and remove the old size 00
bucket and possibly get a size 1 bucket in place.
Check used equipment dealers for the buckets. Hang on to your shorts they
aint cheap.

I once was revamping a Westinghouse MCC for a pumping station. It was
cheaper to order an complete new MCC than it was to buy the new buckets and
starters. So each night I would remove one old and replace it with one new.
Then do the next one. I ended up with old grey sheet metal with new buckets
and new sheet metal and old buckets. We sent the old stuff to salvage. We
kept 2 buckets of each size.

In closing stick to the majors for VFD's personally I like ABB, EE, and SQD.
I have not worked on any of the current generation Toshibas and other
manufactures so your going to have to listen to the rest for them.

 

[Bob]

Sure, no problem,...except for a few details.

Define the HP (or kW) size of your VFD
Define the maximum hieght of the bucket you wish to fit it in
Define the MCC depth in front of the bus bars
Define the rating of the enclosure you can live with
Define how you plan on keeping it cool
Define how you plan to get power to it, i.e. circuit breaker or fuses
Define if you need line and load reactors
Etc. etc. etc.

Retrofitting a VFD into an MCC is problematic but not impossible. The
brand of VFD is irrelevent. None of them were specifically designed to
go into MCCs except the ones sold by the MCC manufacturers themselves,
and those are designed only for their own MCC.The trick is to find
someone who has done it before and can help you avoid some of the
pitfalls. I suggest finding a good panel shop.

 

[Cameron Dorrough]

Does anybody if there is a manufacturer that makes a VFD that would fit into
an existing MCC bucket spot?

Erik, most VFDs are designed to go *outside* the MCC - on the wall
somewhere - for air circulation cooling reasons. It gets very hot inside
some MCCs..

I'm not saying you can't get something, somewhere, though..

Cameron