4000A service...

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Alwayslearningelec

Senior Member
Location
NJ
Occupation
Estimator
Ok this may be a dumb question as I'm sure many are to you guys but I thank you for bearing with me. I am very grateful.

This is my scenario. I have a 3 phase 480V 4000A board and I have to feed about 28 pumps(all 480v 3 phase) nearby that total 2,300 amps. The pumps range from 25HP to 180HP.
Now my question is can I run all these feeds(combine some) from the 4000A board to the pumps or would I go to another distribution board then feed the pumps.

Thanks very much.
 
No MCC?
Need more info.
Drives, starters?
Yes you can run a home run to each motor if you have ~28 breakers?
 
You need more info. starting large motors across the line makes the power co. unhappy most of the time.
A MCC is used most often with starters; you need starters(over loads) to control/protect the motors. By plc, computers,relay logic for control. Unless you plan on turning things on/off by hand?
"Design build" how can you do this if you do not know the process?
What control items will be used: limits, optical, heat, pressure? Two guys and a flag?
 
I'm almost at a loss for words.
It boggles my mind that someone would give you this job to look at as an estimator with so little data and no engineering input.
The possible methods of addressing this are numerous depending on many of the things sameguy mentions, as well as AIC information.
An engineer would spend many hours making the determination as to the best approach,and, truthfully, with the lack of field experience you seem to have on these projects it appears to be a disaster in the making.
My apology for my input, but I am aghast.
 
normally, a mcc would be used for something like this.

you'd have to look at it both ways, cause small ampacity
breakers in a large frame size are prohibitively expensive
in 600 volt.....

and is the level of control you need simply closing a breaker
and letting it run?

if i were putting something like this together, i'd do it in two
parts.... the engineering, and the installation.

and before i ordered anything, i'd have an electrical engineer's
wet ink signature on the drawings.

and i'd have gotten a check for the engineering portion of the
program.

i had a large food conglomerate want me do to some process
control, and conveyors, etc. with work being so slow, i was
all happy to do that work.

then they couldn't decide if they wanted to use rob roy or
stainless conduit and fittings, and wanted it quoted both ways.
they also wondered if it would be ok to use emt, with pvc sch. 40
sleeved over it, for appearance... 'cause they said they saw that
in a plant, and it looked ok.

in a NSF compliant food prep area, with washdown.

emt.

and their level of understanding what they needed seems to
match your customers.

bad feeling in the stomach. walked away from that one, not looking
back.

and it was $170k gross.

good luck with it. i'd get a PE onboard before i went further.


randy
 
augie47 said:
I'm almost at a loss for words.
It boggles my mind that someone would give you this job to look at as an estimator with so little data and no engineering input.
The possible methods of addressing this are numerous depending on many of the things sameguy mentions, as well as AIC information.
An engineer would spend many hours making the determination as to the best approach,and, truthfully, with the lack of field experience you seem to have on these projects it appears to be a disaster in the making.
My apology for my input, but I am aghast.
Click to expand...

Thanks Augie:D:D. I just put together a nice bid(by myself) for a temp power job. It had 7 bidders ranging from 2.3 million to 5.8 million with 2 of them being 5.5 million and 5.9. Low was 2.3 million next was 2.9 then was ME at 3.2 then the others. I very well put together estimate on my part I must say. yes I don't have much field experience but 90% of the estimators I have come across don't. I could get by just fine with the knowledge I have but I want to know everything...maybe that's my problem. I'm not the "fake it til you make it" guy. If I don't know it I will say I don't know it. Many of the estimates( not the one mentioned above) I work on I am working with someone else and believe it or not they also (much more my senior) don't know the technical aspects but they just "throw in" what they think it is labor and/or material wise. My goal it to know what I am talking about as much as possible about as many things "electrically" as possible.
 
Fulthrotl said:
normally, a mcc would be used for something like this.

you'd have to look at it both ways, cause small ampacity
breakers in a large frame size are prohibitively expensive
in 600 volt.....

and is the level of control you need simply closing a breaker
and letting it run?

if i were putting something like this together, i'd do it in two
parts.... the engineering, and the installation.

and before i ordered anything, i'd have an electrical engineer's
wet ink signature on the drawings.

and i'd have gotten a check for the engineering portion of the
program.

i had a large food conglomerate want me do to some process
control, and conveyors, etc. with work being so slow, i was
all happy to do that work.

then they couldn't decide if they wanted to use rob roy or
stainless conduit and fittings, and wanted it quoted both ways.
they also wondered if it would be ok to use emt, with pvc sch. 40
sleeved over it, for appearance... 'cause they said they saw that
in a plant, and it looked ok.

in a NSF compliant food prep area, with washdown.

emt.

and their level of understanding what they needed seems to
match your customers.

bad feeling in the stomach. walked away from that one, not looking
back.

and it was $170k gross.

good luck with it. i'd get a PE onboard before i went further.


randy
Click to expand...

Thanks very much Fulthrot
 
I would not be messing with a 4000A anything without having an engineer that actually understands that kind of stuff looking at it very closely.



Sometimes it is practical to put several MCCs scattered around the area to service motors in those areas and just run a single feeder to each MCC.

Sometimes it makes sense to have local combination starters near the motors since in most cases you are going to have to put disconnects near motors.

OTOH, for controlling the starters, it's usually more convenient to have them in an MCC. BTW, you can get 30" wide empty MCC sections that bolt onto one end or the other of an MCC and are a great place to put PLC and associated I/O equipment. You can even have an empty bucket in each shipping section where you can put remote I/O so you don't have to disconnect anything control wise for shipping. We built many dozens of MCCs this way every year.
 
augie47 said:
I'm almost at a loss for words.
It boggles my mind that someone would give you this job to look at as an estimator with so little data and no engineering input.
The possible methods of addressing this are numerous depending on many of the things sameguy mentions, as well as AIC information.
An engineer would spend many hours making the determination as to the best approach,and, truthfully, with the lack of field experience you seem to have on these projects it appears to be a disaster in the making.
My apology for my input, but I am aghast.
Click to expand...

We get these all of the time. Most of the engineered jobs we see are terrible designs.
There's nothing here that a good design/build EC couldn't do in his sleep.
Lots of factors and considerations to be made (AIC, distance to motors, factory furnished starters, VFD's vs. centralized motor control), but nothing scary about it.
 
petersonra said:
I would not be messing with a 4000A anything without having an engineer that actually understands that kind of stuff looking at it very closely.



Sometimes it is practical to put several MCCs scattered around the area to service motors in those areas and just run a single feeder to each MCC.

Sometimes it makes sense to have local combination starters near the motors since in most cases you are going to have to put disconnects near motors.

OTOH, for controlling the starters, it's usually more convenient to have them in an MCC. BTW, you can get 30" wide empty MCC sections that bolt onto one end or the other of an MCC and are a great place to put PLC and associated I/O equipment. You can even have an empty bucket in each shipping section where you can put remote I/O so you don't have to disconnect anything control wise for shipping. We built many dozens of MCCs this way every year.
Click to expand...

Thanks Peter...great info
 
iwire said:
Holy back from the dead Batman. :grin:

Nice to see you Randy.
Click to expand...

I second that. welcome back Randy!! How's the home theatre holding up?

Horsegoer, Randy knows his stuff. His advice is good as are the others offered up here.

Last large MMC I saw was at the Proctor and Gamble plant in Long Beach...unfortunately I saw it after it blew up from intrusion of acid-wash water from the room above. What a mess.
 
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