rojhan123
Member
- Location
- Philippines
Good day just want to ask about the size of conductor you would recommend for use in a 2000A 3 phase main feeder for a residential building?
SIZE of Main Feeder conductor for a 2000A
- Thread starter rojhan123
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electrofelon
Senior Member
- Location
- Cherry Valley NY, Seattle, WA
Hard to give a definitive answer without more information. Are these service conductors or a feeder? What type of equipment do they terminate on? Are you familiar with table 310.15(b)(16) and which temperature column to use?
- Location
- New Jersey
- Occupation
- Journeyman Electrician
There are many variables but for us we would likely use 5 sets of 600 kcmil copper conductors. 420*5=2100 amps
rojhan123
Member
- Location
- Philippines
I mean sir service conductor..,yup i'm familiar with that, so i am asking now is what size of parallel set of conductors would be recommended to be used for that 2000AT main breaker?
petersonra
Senior Member
- Location
- Northern illinois
- Occupation
- engineer
14 sets of 1/0. 
Coppersmith
Senior Member
- Location
- Tampa, FL, USA
- Occupation
- Electrical Contractor
14 sets of 1/0.
Personally, I would much rather bend 1/0 than 600 MCM. So not as crazy as it sounds.
Not sure how you legally land 14 of them tho.
- Location
- New Jersey
- Occupation
- Journeyman Electrician
Why 4 CCC's?
310.15(B)(5)(c). Based on the posed question, we either need to assume a majority of the load is nonlinear OR we need to assume it is not. I am making the assumption it is to be on the safer side.
jumper
Senior Member
- Location
- 3 Hr 2 Min from Winged Horses
OP said residential. Doubtful that the majority of loads is non-linear.
computers, cell and tablet charges, microwaves, possibly LED lighting, flat screen TVs, newer refrigerator, the list goes on. What would be non-linear; no current returning on the neutral? Since we do not know for fact, it is an assumption either way would it not be?
jumper
Senior Member
- Location
- 3 Hr 2 Min from Winged Horses
Yep, but I have not seen any real studies or info that says a standard resi noodle is likely to be a CCC.
Nonlinear Load.
A load where the wave shape of the
steady-state current does not follow the wave shape of the
applied voltage.
Informational Note: Electronic equipment, electronic/
electric-discharge lighting, adjustable-speed drive sys-
tems, and similar equipment may be nonlinear loads
- Location
- New Jersey
- Occupation
- Journeyman Electrician
I wouldn't assume that you had more than 50% non-linear.
Carultch
Senior Member
- Location
- Massachusetts
Non-linear loads put harmonic currents on the supply circuit. In particular, it is the 3rd harmonic and other multiples of 3, that matter most. 180 Hz when 60 Hz is the nominal frequency, and multiples thereof.
Unlike the fundamental 60 Hz currents that add up to zero when loads are balanced, 3rd harmonic currents and subsequent multiples accumulate constructively on the neutral, even if the three phases are balanced. So when these harmonic currents are significant, the neutral carries enough current to generate heat, even with balanced phase conductors.
Can anyone speak to how you would quantify the 50% nonlinearity of a mix of loads? In otherwords, what would I look for on a datasheet, and how would I add up the value for all loads in a given panelboard?
- Location
- Placerville, CA, USA
- Occupation
- Retired PV System Designer
If you are looking for a rule you can blindly apply, I have nothing for you.
But if the equipment gives a Total Harmonic Distortion figure for the load current, I would say anything less than 50% would be reassuring.
If they gave specific figures for each harmonic, it would be even better.
Just to clarify this, I understand what non-linear loads are. I was asking what loads would one assume for a residential project would not be considered non-linear?
- Location
- Placerville, CA, USA
- Occupation
- Retired PV System Designer
Given modern energy and interference requirements for lights, for TVs, and for computer power supplies, I would have to say very little.
Very old computers, very old CFLs, maybe.
Cell and other chargers, maybe, but the wattage is so low that I would ignore them.
Possibly inverter type heat pumps, but very unlikely there too.
There are far more opportunities for non-linear loads in a commercial/industrial environment.
- Location
- New Jersey
- Occupation
- Journeyman Electrician
A good portion of the load in a residential building is 3Ø elevators, fans, pumps, heaters, etc. IMO there are no real sizable harmonic loads that would get you near the 50% threshold.
- Location
- San Francisco Bay Area, CA, USA
- Occupation
- Electrical Engineer
99% of what I get involved with is industrial now, but I just did some volunteer work at an applicable project this week. It's a managed care facility, mostly developmentally disabled people so the 18 individual living units do not have stoves or ovens. The heat and water heater system is all gas and the commercial kitchen is all gas cooking. The electric loads are the elevator, which has a VFD on it (I was the one to discover that so I know for sure), the 2 Air Handlers, which is where they are wanting to ADD new VFDs, and the plugs and lights. All of the 18 rooms have TVs plus a giant screen system in the entertainment room, they estimated that almost all of the residents have some sort of gaming system hooked up to the TVs and some sort of music system, most of them have PCs or tablets, and all of the lighting is either Fluorescent, CFL or LED. The only significant electrical loads I found that were linear were the 2 large commercial refrigerators and a freezer (the laundry is off site). My estimate was 90% non-linear loads! It was kind of an eye opener really.
- Location
- Placerville, CA, USA
- Occupation
- Retired PV System Designer
Just how non-linear (in terms of distortion power factor) was the total load?
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