MCC or Panelboard?

[montericci]

Hello group.

I have been given the task to design a replacement for an existing 480V, 3 ph, 3-wire, 400A, MCC in a wastewater plant.
The MCC will contain 3) 1/2 hp starters for exhaust fans, 1) 1-1/2hp starter for a larger exhaust fan (that may go away), 1)soft start for a digested sludge pump and the remaining loads are all feed breakers to existing equipment and control panels as well as a 120/208, 3 phase XFMR and lighting panel.

My questing is: Is it economically beneficial to use another MCC or would a panelboard feeding small enclosed starters be smarter. The largest loads out there are 2) 75HP blowers and they have new VFDs feeding them and 2) 7-1/2 HP sludge pumps that also have new VFDs.

I'm thinking and I-Line panelboard may be less expensive and perform just as well, let me know what you think?

Thanks,

Monte

 

[kingpb]

Hello group.

I have been given the task to design a replacement for an existing 480V, 3 ph, 3-wire, 400A, MCC in a wastewater plant.
The MCC will contain 3) 1/2 hp starters for exhaust fans, 1) 1-1/2hp starter for a larger exhaust fan (that may go away), 1)soft start for a digested sludge pump and the remaining loads are all feed breakers to existing equipment and control panels as well as a 120/208, 3 phase XFMR and lighting panel.

My questing is: Is it economically beneficial to use another MCC or would a panelboard feeding small enclosed starters be smarter. The largest loads out there are 2) 75HP blowers and they have new VFDs feeding them and 2) 7-1/2 HP sludge pumps that also have new VFDs.

I'm thinking and I-Line panelboard may be less expensive and perform just as well, let me know what you think?

Thanks,

Monte

The bigger question is what does your client want? If they don't care than its an installed cost issue.

Another question; is it contained in an environmentally controlled space? Wastewater plants are nasty creatures and require a lot of thought in how to keep the gear away from the environmental influences. It may be easier to protect an MCC than a bunch of individual components.

 

[zog]

Hello group.

I have been given the task to design a replacement for an existing 480V, 3 ph, 3-wire, 400A, MCC in a wastewater plant.
The MCC will contain 3) 1/2 hp starters for exhaust fans, 1) 1-1/2hp starter for a larger exhaust fan (that may go away), 1)soft start for a digested sludge pump and the remaining loads are all feed breakers to existing equipment and control panels as well as a 120/208, 3 phase XFMR and lighting panel.

My questing is: Is it economically beneficial to use another MCC or would a panelboard feeding small enclosed starters be smarter. The largest loads out there are 2) 75HP blowers and they have new VFDs feeding them and 2) 7-1/2 HP sludge pumps that also have new VFDs.

I'm thinking and I-Line panelboard may be less expensive and perform just as well, let me know what you think?

Thanks,

Monte

Economically the best thing would be to replace the buckets and leave the MCC structure in place.

 

[petersonra]

The least expensive solution probably is to have a UL508a shop make you a motor control panel. But, my guess is they will want an MCC.

Rebuilding an old MCC with new buckets usually costs more than just replacing it IME. Field labor is insanely expensive and the sheet metal structure of an MCC is usually not real expensive. OTOH, replacing or adding a few buckets might be cost effective.

A lot depends on things you have not told us.

Is the existing MCC worth trying to rehab? It might be in bad enough condition it is not worth trying to save. Parts might not even be available.

Can the existing wiring and conduits be reused?

Does the existing MCC SCCR meet or exceed the short circuit current available? If not it is probably a good candidate to rip out as it probably can't be effectively rehabbed.

Lots of other factors to consider as well. Some of them may only become obvious with a lot more information, some of which you might not even know you need to know until you find out other things.

Panelboards feeding combination starters are going to entail expensive field labor.

 

[zog]

Rebuilding an old MCC with new buckets usually costs more than just replacing it IME. Field labor is insanely expensive and the sheet metal structure of an MCC is usually not real expensive. OTOH, replacing or adding a few buckets might be cost effective.

.

It's the down time that is expensive.

 

[petersonra]

It's the down time that is expensive.

It is all but impossible to say what is "best" for his situation given we know so little about it.