Allowable Voltage Drop

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KWH

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The power company changed the location where my secondary's will terminate on a new job still in the planning stages. I was wanting to make sure I did not need to make adjustments for voltage drop since the new location almost doubled the distance, concerning the whole service would you base this on 3% or 5%.

Thanks
 
I would use 2% just to be on the safe side...
See 210.19 A1 FPN #4

The note says that the 3% is just for a branch circuit. For the Feeder and the Branch circuit its a total of 5%.
 
xformer said:
I would use 2% just to be on the safe side...
See 210.19 A1 FPN #4

The note says that the 3% is just for a branch circuit. For the Feeder and the Branch circuit its a total of 5%.
Click to expand...

But it has also not mentioned clearly that for feeder should be 2%.
I can gues it like this

It is assential, not to increase than 3% for branch and the total branch plus feeder drop should be less than 5%.

Suppose,
I calculate voltage drop for branch it comes 2% and I calculate for feeder it comes 2.7%
The total becomes 4.7%
Am I wrong?
 
If you based your load calcs on the NEC your over-engineered to begin. Can you give us the details such as load, system, length, conductor size, type, ect?
 
Hameedulla-Ekhlas said:
But it has also not mentioned clearly that for feeder should be 2%.
I can gues it like this

It is assential, not to increase than 3% for branch and the total branch plus feeder drop should be less than 5%.

Suppose,
I calculate voltage drop for branch it comes 2% and I calculate for feeder it comes 2.7%
The total becomes 4.7%
Am I wrong?
Click to expand...

I am in agreement with you that 2% and 2.7% = 4.7% Which would be less than the 5% which will provide for reasonable efficiency...
 
xformer said:
Are you saying that by calculating each to 3% is safe due to over-engineering??
Click to expand...

Just voicing experience, 220 is very conservative to what you will see in the field for a service at full load. And as stated in a previous post, VD is a FPN, not enforceable for this application.
 
Hameedulla-Ekhlas said:
But it has also not mentioned clearly that for feeder should be 2%.
I can gues it like this

It is assential, not to increase than 3% for branch and the total branch plus feeder drop should be less than 5%.

Suppose,
I calculate voltage drop for branch it comes 2% and I calculate for feeder it comes 2.7%
The total becomes 4.7%
Am I wrong?
Click to expand...

% of what? The delivered voltage at each point, the delivered voltage at the service point, at the use point, of the nominal value?

Again these values are not regulated and defined by the NEC.
 
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Unless they changed it this is still a foot note and not code.
With out real numbers it is hard to say if you have a problem. Double what ? If original was 50 feet and your now 100 might not be problem but if 100 just went to 200 then yes worry.
 
KWH said:
The power company changed the location where my secondary's will terminate on a new job still in the planning stages. I was wanting to make sure I did not need to make adjustments for voltage drop since the new location almost doubled the distance, concerning the whole service would you base this on 3% or 5%.

Thanks
Click to expand...
The only one that can truly provide enough info to make that determination is the POCO... because it all depends on what voltage they will be supplying you with, actual based on your calculated load... not the nominal... you already know that.

In summary, if you don't know what you are starting with, how can you plan for voltage drop % and stay above nominal tolerance.
 
weressl said:
% of what? The delivered voltage at each point, the delivered voltage at the service point, at the use point, of the nominal value?

Again these values are not regulated and defined by the NEC.
Click to expand...

Suppose I have
Generator
1- Main Distribution Panel (MDP)
2-Panel Board
3-Equipment

From Generator to Main Distribution panel for feeder voltage drop is 0.5%
From Main Distribution panel to panel board ( which is located in building) for feeder is 2.2% drop
From panel Board to equipment ( which is branch ) is 2%

Now,
The total voltage drop for feeder becomes 2.7%
The total voltage drop for branch becomes 2%

The total voltage drop for branch + feeder becomes 4.7%

Now any comment?
 
More Info on the Service

More Info on the Service

The service is 400amp 120/240 single phase underground

The distance is 250ft

I have #250al paralled in 2 1/2" pvc ( 3 per conduit )

The connected load for the service is 60kw

The service consists of (2 ) 200amp main breaker panels

The POCCO change added about 120ft to my secondary length.

Thanks
 
The distance I listed is incorrect

The distance I listed is incorrect

The correct length is 190ft not 250ft


Thanks
 
KWH said:
The service is 400amp 120/240 single phase underground

The distance is 250ft

I have #250al paralled in 2 1/2" pvc ( 3 per conduit )

The connected load for the service is 60kw

The service consists of (2 ) 200amp main breaker panels

The POCCO change added about 120ft to my secondary length.

Thanks
Click to expand...

A quick calc shows that you may only be off by .54v for 5%. If correct I would not worry about it.
 
The total length is 190ft

The total length is 190ft

The total secondary length is 190ft.


Thanks
 
This is a commercial project

This is a commercial project

This is a funeral home , the only real load is the A/C's it has gas heat, mainly just general lighting and receptacle loads
 
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