UTILITY NIGHTMARE

[jaggedben]

I don't think there is a specific definition of or process to compute service size in the NEC. ...

For customer owned stuff, Article 220.

 

[Hv&Lv]

I interpret this mess as when there is no main disconnect the utility adds up the size of the disconnects to determine the service size. I don't feel like theyre wrong. Your 200 amp main with 400 amps of breakers behind it example is different because you have the one 200 amp main making it a 200 amp service. Service size is determined my main ocpd no?

Then the last sentence of my post would be easiest.
limit the power coming out of the transformer.

 

[Todd0x1]

I don't think there is a specific definition of or process to compute service size in the NEC. Where there are multiple service disconnects I always take the service size to be the ampacity of the service entrance conductors. Once I did a 2-200A service with two sets of 250 AL in a common riser, so 368 amps of conductor. This area had a plan review requirements for equipment including and over 400 amps. I figured it didn't need plan review so I just got an over the counter permit, but they kicked it back to me said it needed plan review. So yeah the multiple disconnect thing can be a little tricky without very specific definitions.

Sounds like they did the same thing to you as what happened to OP where service size = sum of disconnects. I wonder if there is any published standard for this anywhere or if its just a 'this is how its done'. Seems like method for determining service size should be in the NEC....

 

[ggunn]

Can you just change the fuses to 200s and then swap them back when the utility planner field engineer guy whatever is done with the project?

Many utilities I have encountered rate the service in terms of the rating of the switch(es), not the rating of the fuses. They are wise to your tricks.

 

[electrofelon]

.

Many utilities I have encountered rate the service in terms of the rating of the switch(es), not the rating of the fuses. They are wise to your tricks.

 

[PE (always learning)]

Many utilities I have encountered rate the service in terms of the rating of the switch(es), not the rating of the fuses. They are wise to your tricks.

ok so then why have any demand load calculations? Shouldn't utility standards mesh with NEC on certain issues like this? Especially when utilities use demand load calculations all the time on their equipment.. The utility standard that I received never mentioned that the service size is equal to the sum of the disconnects.

 

[Hv&Lv]

ok so then why have any demand load calculations? Shouldn't utility standards mesh with NEC on certain issues like this? Especially when utilities use demand load calculations all the time on their equipment.. The utility standard that I received never mentioned that the service size is equal to the sum of the disconnects.

Call the utilities commission

Submit A Complaint | Missouri Public Service Commission

psc.mo.gov

 

[PE (always learning)]

Call the utilities commission

Submit A Complaint | Missouri Public Service Commission

psc.mo.gov

The issue was actually with the utility in the "Peoples Republic" of Illinois

 

[Todd0x1]

ok so then why have any demand load calculations? Shouldn't utility standards mesh with NEC on certain issues like this? Especially when utilities use demand load calculations all the time on their equipment.. The utility standard that I received never mentioned that the service size is equal to the sum of the disconnects.

I think they use the demand data more to forecast energy purchases and for system planning. I really think service size = main disconnect or all main disconnects added together. What if you had the installation you detailed in your post, but your demand calc showed 50 amps of load, do you have a 50 amp service?

 

[texie]

The issue was actually with the utility in the "Peoples Republic" of Illinois

In my case, it is a city owned utility and in Colorado municipal owned utilities are exempt from PSC oversight. They answer to nobody except city council.

 

[PE (always learning)]

I think they use the demand data more to forecast energy purchases and for system planning. I really think service size = main disconnect or all main disconnects added together. What if you had the installation you detailed in your post, but your demand calc showed 50 amps of load, do you have a 50 amp service?

Whether or not the service size is 600 or 900 amps, the utility will still size the transformer based on the demand calculations. So if I did have a service with a demand load that low, the utility would probably still size the transformer based on what ever is shown on the load sheet.

 

[petersonra]

Whether or not the service size is 600 or 900 amps, the utility will still size the transformer based on the demand calculations. So if I did have a service with a demand load that low, the utility would probably still size the transformer based on what ever is shown on the load sheet.

more likely they will size the transformer at 30-50% of what your service load calculation says. whatever std size transformer they stock in that range.

 

[electrofelon]

more likely they will size the transformer at 30-50% of what your service load calculation says. whatever std size transformer they stock in that range.

I agree. First thing the POCO does is throw any NEC based calcs in the garbage/recycle bin.

 

[steve66]

The issue was actually with the utility in the "Peoples Republic" of Illinois

Both Ameren and Con-Ed can be a real pain to work with. Very inflexible, and they just don't care what any of their standards cost the installer or end user. I worked with Duke Energy on a couple of projects and they made everything so simple.

But that said, I can also understand why they are resistant. In areas where they have 3 phase, having too much single phase load unbalances their system. Ameren has standard service sizes, voltages and so on. And I believe 400A is the maximum single phase service.

Do they even make a single phase, 600 amp CT cabinet? If its not too late to change, just make the service 3 phase and put the (3) disconnects on A-B, B-C, and C-A. Just make sure everything is rated for 208V. Some residential HVAC equipment may be listed for 240V only.

 

[PE (always learning)]

Both Ameren and Con-Ed can be a real pain to work with. Very inflexible, and they just don't care what any of their standards cost the installer or end user. I worked with Duke Energy on a couple of projects and they made everything so simple.

But that said, I can also understand why they are resistant. In areas where they have 3 phase, having too much single phase load unbalances their system. Ameren has standard service sizes, voltages and so on. And I believe 400A is the maximum single phase service.

Do they even make a single phase, 600 amp CT cabinet? If its not too late to change, just make the service 3 phase and put the (3) disconnects on A-B, B-C, and C-A. Just make sure everything is rated for 208V. Some residential HVAC equipment may be listed for 240V only.

Unfortunately it's too late to change the service from single phase to three phase as the transformer is already in place.

I moved some of my loads and reworked my demand calculations so that I could downsize the fusible disconnects to equal 600 amps worth of service. I'm keeping my fingers crossed that this will be approved.

I won't say what utility I'm dealing with just cause I'm trying to keep it a little confidential, but I totally agree with your statement. The utility had everything they needed from me 8 months ago and again after approval by the AHJ, approval from the utility, and final install, they bring this issue to the table. It seems like a cruel joke sometimes...

 

[Fishbrain]

I know you are located in Missouri.
My question is:
Does your state, POCO or AHJ allow an unregistered engineer- in- training individual to submit and hopefully expect to have drawings, design and load calculation from a trainee?

A draftsman, electrician, self-proclaimed expert can do those things that you did.

The scope of work you mentioned is something that a PE need to look at. . . and eventually affix his stamp and seal if he feels it's done right.
Not that you didn't do it right. . . but that's what PE's do for a living.

Fish

Unfortunately it's too late to change the service from single phase to three phase as the transformer is already in place.

I moved some of my loads and reworked my demand calculations so that I could downsize the fusible disconnects to equal 600 amps worth of service. I'm keeping my fingers crossed that this will be approved.

I won't say what utility I'm dealing with just cause I'm trying to keep it a little confidential, but I totally agree with your statement. The utility had everything they needed from me 8 months ago and again after approval by the AHJ, approval from the utility, and final install, they bring this issue to the table. It seems like a cruel joke sometimes...

.

 

[Hv&Lv]

I know you are located in Missouri.
My question is:
Does your state, POCO or AHJ allow an unregistered engineer- in- training individual to submit and hopefully expect to have drawings, design and load calculation from a trainee?

A draftsman, electrician, self-proclaimed expert can do those things that you did.

The scope of work you mentioned is something that a PE need to look at. . . and eventually affix his stamp and seal if he feels it's done right.
Not that you didn't do it right. . . but that's what PE's do for a living.

Fish


.

Check out post #28

 

[Fishbrain]

Nothing in that post has anything to do with the aforementioned issue. This is a civil case. . . not a criminal case.
Before it gets to this level-- appropriate avenue must have been exhausted before said criminal complaints are launched.

It should be reviewed by the Board of Engineers (if there is one in the area) first before going to the police.
Police department is not comprised of engineers.

Fish

 

[PE (always learning)]

I know you are located in Missouri.
My question is:
Does your state, POCO or AHJ allow an unregistered engineer- in- training individual to submit and hopefully expect to have drawings, design and load calculation from a trainee?

A draftsman, electrician, self-proclaimed expert can do those things that you did.

The scope of work you mentioned is something that a PE need to look at. . . and eventually affix his stamp and seal if he feels it's done right.
Not that you didn't do it right. . . but that's what PE's do for a living.

Fish


.

wow, that escalated quickly

This is an old username, I am no longer an engineer in training, I just haven't updated the user name (I probably should now that people are making wild assumptions..) I've been a licensed engineer for 3 years.

My seal was not on this drawing set, but I am a professionally licensed engineer as originally stated.

This drawing set was checked by myself and the licensed engineer that signed and sealed these drawings.

The said information was submitted to the utility 8 months ago and they sat on it and waited for everything to be installed until making an issue of it.

 

[PE (always learning)]

Nothing in that post has anything to do with the aforementioned issue. This is a civil case. . . not a criminal case.
Before it gets to this level-- appropriate avenue must have been exhausted before said criminal complaints are launched.

It should be reviewed by the Board of Engineers (if there is one in the area) first before going to the police.
Police department is not comprised of engineers.

Fish

Does everyone jump to conclusions this quickly?

Even if I was still an engineer in training, which I am not...

Why couldn't I ask questions on here while working under a professional engineer?