Red tagged for voltage drop what gives? (NY)

[Adamjamma]

C405.9 Voltage Drop in Feeders and Branch Circuits

The total voltage drop across the combination of feeders and branch circuits shall not exceed 5 percent.

The code doesn’t say calculated voltage drop. It says voltage drop. Which means actual voltage drop

problem is that you have two problems most of the times at inspections I have dealt with, first is circuit is dead, so can only use nominal voltage and distance to calculate voltage drop, and second is normally unless you are actually installing a machine you just have an outlet there at one end and a breaker at the other..
Now, to me it seems pretty simple to use voltage drop as part of my calculations for the proper cable sizing. I mean the formula is not that hard and, if I remember from last time I did it, the inverse of the voltage drop formula can pretty much give you the cable size.. You only need to know are you using copper or aluminum, and is it single phase or three phase, and use a good calculator.. Had the formula somewhere- think it is like 2KID/circular mils..

 

[ramsy]

Yes he uses an app.
Its a long complicated run in a huge old warehouse, and do to a entire panel being removed this one load had to be re feed from afar.
Also due to avoiding a concrete bore thru 18" wall, and re-using an existing pipe run almost 1/3 the way it ended up being 450 (ish) feet of conductor, just under a full spool of 10's.
Its a 3 phase 208 load about 17 amps that is remaining, the rest of the area got demoed.

The inspectors calculator was best case vs actual (PF) or (R) heat from terminations, continuous or motor loads, CCC's, or ambient.

~7% VD was best case for balanced 3-Phase 6124 Watt load 450ft away using #10cu.
~4% VD was best case using #8cu: no motors or continuous (+25%), max 3 CCC's in any conduit, and max 30c ambient.

 

[nickelec]

Vd is also a code amendment in NYC. Required 3%max on feeders and 5%max to the last branch circuit receptacle.

Sent from my SM-S906U using Tapatalk

 

[tortuga]

The code doesn’t say calculated voltage drop. It says voltage drop. Which means actual voltage drop

Here in Oregon we have a very similar energy code and they do go by your article 220 calc, except you take out the continuous load %. The reason for the 220 calc is if you don't have anything built yet all you have is a 220 calc, and so for consistency they have to use that for compliance of reworked existing equipment.
In my experience they are very easy going and will accept any way you want to prove your 5% but I have also been doing it for a over a decade.
They are not as easy going on the other parts of that energy code like the 'lighting budget'.
Some buildings get these third party green energy certifications and those people also look that stuff over more closely.

I have always thought, and I know others on here disagree, 110.10 implies some voltage drop in the NEC code.
In that you can't have so much voltage drop that the OCPD wont function. And 110.3(B) also. If say a motor is marked 230V +/- some % in the instructions its a violation to have excess drop.

 

[Tulsa Electrician]

I have always thought, and I know others on here disagree, 110.10 implies some voltage drop in the NEC code.
In that you can't have so much voltage drop that the OCPD wont function. And 110.3(B) also. If say a motor is marked 230V +/- some % in the instructions its a violation to have excess drop.

True that. Seen it first hand the other day.

 

[tank728]

Vd is also a code amendment in NYC. Required 3%max on feeders and 5%max to the last branch circuit receptacle.

Sent from my SM-S906U using Tapatalk

I believe it is 2% on feeders.

 

[gene6]

I believe it is 2% on feeders.

I don't mean to drag this out, but I am doing my research now so I don't get bit twice, (ok ok well my apprentice is).
This appears to be the current NYC electrical code amendments
https://www1.nyc.gov/assets/buildings/pdf/ll39of2011_electrical_code.pdf
And it says:

SECTION 210.19
Subsection 210.19(A)(1) - Add a new sentence at the end of the paragraph before the first
Exception to read as follows:
Conductors of branch circuits shall be sized to allow for a maximum voltage drop of 3 percent at
the last outlet supplying light, heat or power and the maximum voltage drop allowable for feeders
and branch circuit combined shall not exceed 5 percent.
FPN No. 4- - Delete the FPN in its entirety.
Subsection 210.19(A)(4) - Revise the first sentence of the paragraph by replacing “14 AWG” with
“12 AWG”
Exception No. 3: Add a new Exception No. 3 to read as follows:
Exception No.3: Where compliance with the applicable Energy Conservation Code is
mandated voltage drop requirements of that code shall apply

But please post a link or code ref if this is out of date thank you all for your input.

 

[Jerry Solar]

Voltage Drop Calculator - for single and 3 phase ac systems and dc systems

You can use the link above for voltage drop calculations. Most accepted values are 2% for feeders and 3% for branch circuits for a total of 5%.