Service Rating

[tico17]

HI, this im new here, and i have a question, i have a panel load of 200 amps and another panel load of 135 amps, both panels go inside but the architect did not draw the service, it only says panels are 225amp main lug.

so im assuming its 2- 225amps main breakers outside but im having a hard time choosing the meter do i need a 400 amp meter since its above the continuos load or i need something bigger? how do i figure this out??????/

 

[eHunter]

HI, this im new here, and i have a question, i have a panel load of 200 amps and another panel load of 135 amps, both panels go inside but the architect did not draw the service, it only says panels are 225amp main lug.

so im assuming its 2- 225amps main breakers outside but im having a hard time choosing the meter do i need a 400 amp meter since its above the continuos load or i need something bigger? how do i figure this out??????/

Does the POCO Blue Book give any guidance?

 

[infinity]

How did you calculate the 200 and 135 amp loads?

 

[tico17]

tico17

tico17

the architect did the demand calculations he came up with this, the remaining amps are for future use. my problem is choosing this meter i never ran into this problem before

 

[tico17]

How did you calculate the 200 and 135 amp loads?

the architect did the demant calculation, and he asked for 2-225 amp panels

 

[Smart $]

the architect did the demand calculations he came up with this, the remaining amps are for future use. my problem is choosing this meter i never ran into this problem before

You'll have to first verify whether the 200a and 135A figures include 125% for continuous loads. The panel ratings have no bearing on meter rating, but the meter rating will have to be sized for planned future loads. If none are planned, then it only has to accomodate the calculated load plus 25% for continuous.

 

[augie47]

My first step would be to take a copy of the load calculations and the main breaker sizes to your local POCO. There is no "standard" way it is handled. Different power companies have different rules depending on loads, phases, etc. Some use CTs above a certain point.

 

[templdl]

HI, this im new here, and i have a question, i have a panel load of 200 amps and another panel load of 135 amps, both panels go inside but the architect did not draw the service, it only says panels are 225amp main lug.

so im assuming its 2- 225amps main breakers outside but im having a hard time choosing the meter do i need a 400 amp meter since its above the continuos load or i need something bigger? how do i figure this out??????/

It appears as though the architect want for you to take the responsibility that should be his. Ask then to specify it, that they overlooked it in their specs.

 

[texie]

HI, this im new here, and i have a question, i have a panel load of 200 amps and another panel load of 135 amps, both panels go inside but the architect did not draw the service, it only says panels are 225amp main lug.

so im assuming its 2- 225amps main breakers outside but im having a hard time choosing the meter do i need a 400 amp meter since its above the continuos load or i need something bigger? how do i figure this out??????/

Your location indicates to me that you are in FPL territory. If that's the case I can almost promise you that FPL will allow a direct meter 320/400 meter can. They probably will accept a 400 amp combo meter main with 2, 200 amp main breakers that you can directly feed your 225 amp MLO panels. Forget the 225 amp as a main to each panel (unless load calcs prohibit) if you use a combo meter main unit as this is non standard. A combo meter main of this size and type is very economical in terms of total installed cost and clean looking. But as others said, confirm with FPL. It's been a while since I worked in FPL territory but I'm sure they would not require a CT setup for this as they are anti CT unless you have a demand well north of 600 amps.

 

[tico17]

Your location indicates to me that you are in FPL territory. If that's the case I can almost promise you that FPL will allow a direct meter 320/400 meter can. They probably will accept a 400 amp combo meter main with 2, 200 amp main breakers that you can directly feed your 225 amp MLO panels. Forget the 225 amp as a main to each panel (unless load calcs prohibit) if you use a combo meter main unit as this is non standard. A combo meter main of this size and type is very economical in terms of total installed cost and clean looking. But as others said, confirm with FPL. It's been a while since I worked in FPL territory but I'm sure they would not require a CT setup for this as they are anti CT unless you have a demand well north of 600 amps.

yes, im in florida and CT cabinets are required for 600 amps and up, this a residential job my concern is that in the blue prints he put 225amps for the 200 amp panels the 25amps are for reserve, well thats what the prints says.

at the begining i was going to get a combo with 2-200amps but them i saw the calculation where says 225amps-200amps=25amps reserve. dont want to have a problem with the inspector for changing that number

 

[tico17]

You'll have to first verify whether the 200a and 135A figures include 125% for continuous loads. The panel ratings have no bearing on meter rating, but the meter rating will have to be sized for planned future loads. If none are planned, then it only has to accomodate the calculated load plus 25% for continuous.

so you are saying that i need a meter for at least 418 amps so a 600amp or ct cabinet

200amp+135amps=335amps x 1.25=418amps this is a residential load, i never did a residential load as continuous load??

 

[tico17]

It appears as though the architect want for you to take the responsibility that should be his. Ask then to specify it, that they overlooked it in their specs.

i definatly agree with you, if i design the drawing i should be responsible but i did not designed it

 

[kwired]

HI, this im new here, and i have a question, i have a panel load of 200 amps and another panel load of 135 amps, both panels go inside but the architect did not draw the service, it only says panels are 225amp main lug.

so im assuming its 2- 225amps main breakers outside but im having a hard time choosing the meter do i need a 400 amp meter since its above the continuos load or i need something bigger? how do i figure this out??????/

Lets assume for now the actual art 220 load calculation results are 200 and 135 amps for each panel. There is nothing wrong with feeding main lug panels rated 225 amps for these loads. You could use anything greater or equal than the 200 and 135 figures.

Now remember common bus ratings for panelboards are typically 100, 125, 150, 200, 225, maybe 250 but many jump to 400 after 225. It may be more common to see 225 rated for main lug panels than to see 200 amp rated main lug panels in some instances. So selection of 225 amp main lug panels is not all that surprising. But if these are main lug only there still has to be either a service or other disconnect from say a separately derived system, or a feeder disconnect someplace. Rating of overcurent devices supplying these panels must be at least 200 amps and 135 amps - which next standard size up is 150.

If we still assume the load calc's mentioned above both could be served from a service or feeder with a minimum of 335 amps capacity. Each would still need 200 and 150 minimum overcurrent protection.

The 200 amp supplied panel must have 200 amp minimum ampacity conductors, but the 135 supplied panel can have minimum 135 amp conductors and still be protected at next higher standard device which is 150.

 

[templdl]

i definatly agree with you, if i design the drawing i should be responsible but i did not designed it

Bingo. It's all about what you are responsible for in the completion of the contract. It was certainly convenient for the architect to leave that part out of his drawing. I would consider the drawings incomplete in not providing you with the specification to proceed with the project. I know that are those who would like to be heros but then where is the liability placed.

 

[kwired]

Bingo. It's all about what you are responsible for in the completion of the contract. It was certainly convenient for the architect to leave that part out of his drawing. I would consider the drawings incomplete in not providing you with the specification to proceed with the project. I know that are those who would like to be heros but then where is the liability placed.

Exactly, we have a design, but it is incomplete as we don't have anything in the design about what is to supply this, now maybe that was beyond the scope of the design IDK, but generally the supply is included and is an important part of the overall installation.

 

[Smart $]

so you are saying that i need a meter for at least 418 amps so a 600amp or ct cabinet

200amp+135amps=335amps x 1.25=418amps this is a residential load, i never did a residential load as continuous load??

No, that's not what I'm saying... unless the entire load is continuous, which I doubt very much now that you said it is a residence. Many consider a residence as having no continuous loads (whether there are technically occasions when loads are operated more than 3 hours continuously or not).

 

[tico17]

im surprised, you guys are really smart, thanks for the help since its 200 amps and 135 amps loads, and it says 225 amps panel, the remaining its reserve, i will just put a 200 amp and a 150 amp breaker and tell the inspector its for future if they want to upgrade panel and conduit its there they just have to upgrade the wire for 225 amps.. I think thats the best way to do it since they left it to my imagination

 

[petersonra]

Personally, I would be inclined to put in 200A MLO panels with 200A breakers feeding both of them. The larger wire is probably not that big of a deal, and I would guess there is no difference in cost between the 150A and 200A CB, but there might be.

But I think you also have to accommodate what the architect put on the drawings.

I am not sure the 25A "reserve" makes all that much sense.

 

[kwired]

im surprised, you guys are really smart, thanks for the help since its 200 amps and 135 amps loads, and it says 225 amps panel, the remaining its reserve, i will just put a 200 amp and a 150 amp breaker and tell the inspector its for future if they want to upgrade panel and conduit its there they just have to upgrade the wire for 225 amps.. I think thats the best way to do it since they left it to my imagination

You need to not focus so much on the 225 amp bus rating. Many manufacturers only make limited number of ratings for panel bus, and you need to pick one that is rated equal or higher than your load. You may find 100, 125, 150, 200 and 225 bus for certain "load centers" but get into the commercial and industrial panels and your choices become less, maybe even to the point where only choice is 125, 225 or 400. The panelboard rating is still limited by its main overcurrent device whether it is internal or external to the panel.

 

[Smart $]

Personally, I would be inclined to put in 200A MLO panels with 200A breakers feeding both of them. The larger wire is probably not that big of a deal, and I would guess there is no difference in cost between the 150A and 200A CB, but there might be.

But I think you also have to accommodate what the architect put on the drawings.

I am not sure the 25A "reserve" makes all that much sense.

You need to not focus so much on the 225 amp bus rating. Many manufacturers only make limited number of ratings for panel bus, and you need to pick one that is rated equal or higher than your load. You may find 100, 125, 150, 200 and 225 bus for certain "load centers" but get into the commercial and industrial panels and your choices become less, maybe even to the point where only choice is 125, 225 or 400. The panelboard rating is still limited by its main overcurrent device whether it is internal or external to the panel.

Correct me if I'm wrong, but if the plans are approved and they clearly indicate 225A MLO panels are to be installed, there is no other choice but to install 225A or greater MLO panels. If the feeders and their ocp are not specified, they can be as low as Code allows for the calculated load (200A and 135A according to OP'er).