Is this correct

[jrvazzer]

clients requested in their lease 400A 120/208v 3ph, 4w service for their facility. So you provide a 400A service. The question..... are they really getting 400A. Do they know that they are responsible for loading up their electrical needs to 80 percent of that breaker or fuse main. If the client was requesting 7 watts per sq. ft. and 400A met that and if their limited to 80 percent of the mains. Than actually they are getting 5.6 watt per sq.ft. Is that correct.
sq. footage is 20571'.
Thanks

 

[jumper]

What the clients request and what is needed may be two different things.
How is the load calculated at 7 watts per foot?

Continuous, non- continuous or mixture?

230.42 Minimum Size and Rating.
(A) General. The ampacity of the service-entrance conductors
before the application of any adjustment or correction
factors shall not be less than either (A)(1) or (A)(2).
Loads shall be determined in accordance with Part III, IV,
or V of Article 220, as applicable. Ampacity shall be determined
from 310.15. The maximum allowable current of
busways shall be that value for which the busway has been
listed or labeled.
(1) The sum of the noncontinuous loads plus 125 percent
of continuous loads

 

[iwire]

clients requested in their lease 400A 120/208v 3ph, 4w service for their facility. So you provide a 400A service. The question..... are they really getting 400A. Do they know that they are responsible for loading up their electrical needs to 80 percent of that breaker or fuse main.

You can load the panel and breaker to 100% non-continuous so IMO it would be a 400 amp service. Of course this assumes the conductors are rated 400 amps and no one took advantage of 240.4(B).

 

[jrvazzer]

What the clients request and what is needed may be two different things.
How is the load calculated at 7 watts per foot?

Continuous, non- continuous or mixture?

230.42 Minimum Size and Rating.
(A) General. The ampacity of the service-entrance conductors
before the application of any adjustment or correction
factors shall not be less than either (A)(1) or (A)(2).
Loads shall be determined in accordance with Part III, IV,
or V of Article 220, as applicable. Ampacity shall be determined
from 310.15. The maximum allowable current of
busways shall be that value for which the busway has been
listed or labeled.
(1) The sum of the noncontinuous loads plus 125 percent
of continuous loads

The service voltage is 480v, the engineers provide a transformer 112.5kva with 312 full amps at 1.25 = 390A provide a 400A main C/B. to the clients space. Are they really getting a 400A sevice?

 

[jumper]

The service voltage is 480v, the engineers provide a transformer 112.5kva with 312 full amps at 1.25 = 390A provide a 400A main C/B. to the clients space. Are they really getting a 400A sevice?

How can every load in this building be continuous?

 

[jumper]

How can every load in this building be continuous?

Ignore this, I just did the math and checked 450. I see where you got your numbers. I am gonna bow out of trying to answer your question, it is too complicated for me.

 

[jrvazzer]

Sorry

Sorry

Ignore this, I just did the math and checked 450. I see where you got your numbers. I am gonna bow out of trying to answer your question, it is too complicated for me.

Sorry for confusion:
the client does'nt care about continous. He reads his lease agreement as a contract to receive 400A he looks at the reatility and argues that we are not meeting their agreement.

 

[Designer69]

The service voltage is 480v, the engineers provide a transformer 112.5kva with 312 full amps at 1.25 = 390A provide a 400A main C/B. to the clients space. Are they really getting a 400A sevice?

how are you getting 312 "full" amps lol. that tranny is good for 136A.

 

[jumper]

how are you getting 312 "full" amps lol. that tranny is good for 136A.

Secondary would be 208/120

 

[jrvazzer]

Secondary would be 208/120

yes thats correct.

 

[petersonra]

The service voltage is 480v, the engineers provide a transformer 112.5kva with 312 full amps at 1.25 = 390A provide a 400A main C/B. to the clients space. Are they really getting a 400A sevice?

Are they getting a service at all, or are they getting a feeder?

In any case they have a pretty good argument that they are not getting 400A.

 

[iwire]

Are they getting a service at all, or are they getting a feeder?

I gave up on this one as I have no idea what the set up is.

 

[DARUSA]

Asuming that in a 400 amps service you can apply up to 80% continued loads (320 amps) you transformer will be able to supply only 312 amps not mention non continued load( 400 amps).
If i'm the customer i would like to recibe exactly what I Pay for!!! 400 amps non continued loads!!!

 

[jumper]

Are they getting a service at all, or are they getting a feeder?

In any case they have a pretty good argument that they are not getting 400A.

I gave up on this one as I have no idea what the set up is.

I think I understand what the OP is trying to ask.

Let me use a similar analogy:

If you use 4/0 AL SE to supply a residence, have you provided a true 200 amp service?

 

[iwire]

I think I understand what the OP is trying to ask.

Let me use a similar analogy:

If you use 4/0 AL SE to supply a residence, have you provided a true 200 amp service?

That is not helping me at all.

What would help is a one line riser diagram or a better description of how this is set up.


I am guessing this is what we have

Utility >>> 'service point' >>> 480 volt service >>> Feeder to 112 kva trans >>> OCPD >>> feeder to tenant >>> 400 amp tenant panel.


If that is the set up than I would say they have a 312 amp feeder.


However if it is more like this.

112.5 utility transformer >>>> service >>> 400 amp feeder >>> 400 amp tenant panel.

I would call it a 400 amp supply.

 

[jumper]

Asuming that in a 400 amps service you can apply up to 80% continued loads (320 amps) you transformer will be able to supply only 312 amps not mention non continued load( 400 amps).
If i'm the customer i would like to recibe exactly what I Pay for!!! 400 amps non continued loads!!!

That is not helping me at all.

What would help is a one line riser diagram or a better description of how this is set up.


I am guessing this is what we have

Utility >>> 'service point' >>> 480 volt service >>> Feeder to 112 kva trans >>> OCPD >>> feeder to tenant >>> 400 amp tenant panel.


If that is the set up than I would say they have a 312 amp feeder.


However if it is more like this.

112.5 utility transformer >>>> service >>> 400 amp feeder >>> 400 amp tenant panel.

I would call it a 400 amp supply.

Okay, so a customer is supposed to know the difference between continuous and non-continuous?

The OP does not know what the true load is other than customer saying " I want a 400 amp service". What do you do?

 

[iwire]

Okay, so a customer is supposed to know the difference between continuous and non-continuous?

At this point I am not even thinking about continuous or non-continuous. Right now I am thinking that if there is a 208Y/120 volt feeder supplied by a 112.5 kva transformer on the customer side of the service point the tenant is only getting a feeder with a maximum NEC rating of 311 amps.

 

[jumper]

Bob, this what the OP has:

The question is: "Is his client getting a true 400 amp supply/service/feeder/panel/whatever?"

 

[iwire]

Bob, this what the OP has:

The question is: "Is his client getting a true 400 amp supply/service/feeder/panel/whatever?"

I am just not as sure as that as you are, which is fine, we all read things differently.

If the installation is like the one in the Mike Holt graphic he has a 312 amp feeder regardless of continuous on non-continuous loads.

The transformers max rated output is 312. (And I already said this )

 

[kwired]

Okay, so a customer is supposed to know the difference between continuous and non-continuous?

The OP does not know what the true load is other than customer saying " I want a 400 amp service". What do you do?

The question is does the customer really know what 400 amps means in the first place? His concern should be how much Kw is available that is what he is going to use.

His second concern should be whether the voltage and number of phases is compatible with equipment he is going to use.

Customer in reality probably knows little about elecrical and is only concerned with information provided by people he trusts (engineers/contractors) that he will be able to use what is installed to power what he needs to run plus what ever future plans he may have.