DC MCC question

[twh34d]

Hey everyone. I am an engineer working on replacing an existing DC MCC for a client. It has been almost impossible to find a manufacturer that even makes DC MCC's. I just need a 3 cabinet, around 6 section DC MCC. Some of the sections include Aux Fuel Pump, DC Starting Resistors, Aux lube pump, and an Aux evactor blower. I know Cutler-Hammer has a DC MCC but doesn't deal with Aux fuel pumps, DC staring resistors, or the lube pump. Someone suggested I might get a panel shop to to put it together and just put the motor starters in there. Can anyone suggest a good course or action I could look into? Thanks for your time.

 

[jraef]

Search for marine switchgear manufacturers or panel builders. There is still a lot of DC used in marine systems.

"Our virtues and our failings are inseparable, like force and matter. When they separate, man is no more."
Nikola Tesla

 

[ScottyUK]

Check out the panel shops in steelmaking towns. They might not use it so much in these days of AC servo drives, but DC controlgear was once the bread & butter of these companies.

DC gear takes up as lot more physical room than an equivalent AC rated board. Contactors are bigger, thermal overloads are hideously expensive, resistor banks occupy space...

A-B's 810 series thermal O/L is one of the few available in the UK without spending a serious amount of money. Treat the ratings of AC contactors on DC service with extreme scepticism: in my experience they have short lives and violent deaths when used on DC inductive loads. For preference use a bar & shaft contactor fitted with a magnetic blowout. Same applies to breakers: most require multiple poles in series to get any significant breaking capacity unless you are using very low voltage.

This sounds vaguely like a turbine application from the drives you are wanting to power. If this is the last-ditch protective system, remember that simpler is usually better.


----------------------------------

If we learn from our mistakes,
I'm getting a great education!

 

[dbaird]

We are an OEM of special machinery and have our own panel shop. Check us out on Web:

http://afctool.com/

We would be willing to look at your application and if it falls within our capabilities make you a proposal. If you wish to pursue our help contact me.

David Baird
Electrical/Controls Designer
AFC Tool Co.
davidb@afctool.com
937-275-8700


David Baird
mrbaird@hotmail.com
Sr Controls Designer
EET degree.
Journeyman Electrician.

 

[twh34d]

It is for a turbine project. The existing DC MCC is 30 yrs old and matches the AC. I think they were manufactured by Electric Machinery Mfg. But I called them and they said they haven't made any DC units since the 50's. This stuff looked way newer than the 50's. I guess I'll check out some panel shops. Thanks for all the help guys.