4 awg wire.

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Alaterreur

Alaterreur

Bronze Supporter
Sep 26, 2022
56
Menifee Ca.
I am about to start building our pool and when researching I will need 4 AWG wire due to being over 170 feet and running possibly 3 pumps. My question is can the white (neutral) and green wire be smaller (6 or 8 AWG)? Also where is a good place to buy that amount. Lowes here only has black in 4 AWG.
 
You probably need to get that at a nearby electrical supply company. Given how expensive it is, you want it cut to the size you need. Big box hardware stores aren’t going to have a lot of selection. They can probably also advise on the neutral size as well.
 
Note: Verify all design plans with a qualified electrician before finalizing the design plan.

The neutral is sized to carry the unbalanced load.

The neutral cannot be smaller than the minimum required EGC.


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So the ground (Green Wire) can be smaller. Distance doesn’t matter? I am putting a 60 amp breaker and I was planning on using a 6 or 8 AWG wire for it. Thanks Matt, I will have to search more. I see they sell online but always concerned buying there.
 
JamesW said:
What is the expected total 240 volt load?

What is the total expected 120 volt load?

Will you have a heat pump?

What size breaker will feed the subpanel?
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Looking at getting 3 Intelliflo3 pumps (Sheer descents, primary and secondary spa).On Pentair web site it says 11 amps each. will have Intellicenter to run lights and equipment. No heat pump. Just 400k heater. I am planning on 4 AWG wire to Intellicenter And 60 Amp breaker at the house.
 
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Alaterreur said:
Looking at getting 3 Intelliflo3 pumps (Sheer descents, primary and secondary spa).On Pentair web site it says 11 amps each. will have Intellicenter to run lights and equipment. No heat pump. Just 400k heater. I am planning on 4 AWG wire to Intellicenter And 60 Amp breaker at the house.
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We ran 150ft from the main panel to the load center panel by the pool equipment. We did a 100 amps. It’s oversized but it’s better to have too much than not enough in my opinion.
 
Alaterreur said:
I will need 4 AWG wire due to being over 170 feet
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Because you increased the size of the hot wires for voltage drop control, the size of the ground wire is governed by NEC 250.122(B):

(B) Increased in Size. Where ungrounded conductors are increased in size from the minimum size that has sufficient ampacity for the intended installation, wire-type equipment grounding conductors, where installed, shall be increased in size proportionately, according to the circular mil area of the ungrounded conductors.

So, you will need to increase the size of the EGC proportionately to the increase in the ungrounded hot connectors.
 
Alaterreur said:
I am about to start building our pool and when researching I will need 4 AWG wire due to being over 170 feet and running possibly 3 pumps. My question is can the white (neutral) and green wire be smaller (6 or 8 AWG)? Also where is a good place to buy that amount. Lowes here only has black in 4 AWG.
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At 4awg, you can use black for the hot and neutral conductors, color taped appropriately. The ground must be green.
 
#4 AWG = 41740 Area (circular mils)

#6 AWG = 26251 Area (circular mils)

41740/26251 = 1.59

So, you are increasing the wire size (cross sectional area) of the two hot wires by 1.59 times due to the distance to account for the voltage drop.

So, you also have to upsize the EGC (Equipment Grounding Conductor) by 1.59.

For a 60 amp breaker, the minimum EGC is # 10 AWG copper, which has a cross sectional area of 10383 circular mils.

10,383 x 1.59 = 16,509 circular mils, which corresponds to #8 AWG copper wire.

For a 60 amp service, you can use # 4 AWG copper THHN for the two hot wires and #8 AWG copper THHN for the EGC (Equipment Grounding Conductor aka ground wire) and #8 AWG copper THHN for the neutral wire assuming the neutral will carry less than 25 amps.

Note: Verify all plans with a licensed electrician before committing to any design to make sure that it meets all local code.



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Section 250.122(B) of the National Electrical Code was revised in the 2020 edition to allow qualified persons to size the equipment grounding conductor in certain applications.

This tool may be used by a qualified person to determine the equipment ground conductor size...

ap-concepts.com

GEMI - APC

GEMI built by Advanced Power Concepts. Grounding and EMI Analysis Program For Conduit-Enclosed Power Circuits
ap-concepts.com ap-concepts.com
 
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Section 310.15(B)(7)(4) Grounded conductors shall be permitted to be sized smaller than the ungrounded conductors, if the requirements of 220.61 and 230.42 for service conductors or the requirements of 215.2 and 220.61 for feeder conductors are met.

The neutral is the grounded conductor and it can be smaller that the ungrounded conductors (Hot wires) as long as you meet the requirements and it cannot be smaller than the EGC (ground wire).
 
For the 120 volt loads, you don’t add up all of the loads to calculate the load on the neutral.

For example, if you have loads of 4, 5, 5, 6, 7, and 8 amps for the 120 volt appliances, the total is 35 amps, but the neutral should not see 35 amps.

You want to balance the loads as evenly as possible.

So, a perfect balance would be 17.5 amps on one hot leg and 17.5 amps on the other hot leg.

The closest you can get is to put 5, 5, and 7 (17 amps) on one leg and 4, 6 and 8 (18 amps) on the other leg.

Since the 120 volt loads are distributed across the two hot legs, the additional load on the 240 volt circuit breaker is 18 amps and not the 35 amps total that the 120 volt loads add up to.

So, the most current the neutral should see is 18 amps if you turn on all 120 volt appliances on the one leg with 18 amps.

If you turn on any appliance on the other leg, the current does not add to the current on the neutral, it subtracts from the current.

If you have 18 amps on one leg and turn on the 7 amp appliance on the other leg, the current in the neutral goes down to 11 amps.

This is because the current is more balanced from one hot to the other.

The 120 volt appliance loads that are balanced work like putting (2) 120 volt appliances in series and running them on 240 volts.

When the electrician is wiring the panel, make sure that the 120 volt loads are evenly distributed on both hot legs.

In the example pictured below, the neutrals are carrying 5 amps between the loads on different legs, so the return neutral only has to carry 2 amps back to the main panel.

If the loads are exactly balanced, you don’t even need the return neutral at all.

In the second picture, there are (2) 120 volt 7 amp loads that are both connected together via the neutral wires connecting together on the neutral bar.

In that case, the main neutral to the panel carries no current and you could even disconnect the main neutral and the system would work just fine.

There are specific calculations to determine the current on the neutral, so be sure to follow all rules.

Another thing to consider is if you want any extra capacity for unexpected additions.

For example, maybe the builder decides to go with regular IntelliFlo VSF pumps and they require 16 amps.

If you have 3 pumps, that is 48 amps and that is 80% of the 60 amp breaker, which is the limit for design.

However, that’s assuming that you will run all 3 pumps at full speed at the same time.

Going to a 100 amp design gives you a little bit of spare capacity to handle unanticipated load requirements.

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Alaterreur said:
I thought the intelliflo3 is 11 amps. Is that a misprint?
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The Intelliflo 3 is 11.2 amps as shown in the picture.

3 x 11.2 = 33.6 amps.

The maximum you want to put on the 60 amp breaker is 48 amps which is 80% of 60.

48 - 33.6 = 14.4 amps of available load capacity beyond the 3 pumps.

My point was that maybe you or your builder might want to switch to the IntelliFlo VSF or Intelliflo XF, which require 16 amps.

Maybe the builder will find that the Intelliflo 3 is not available or maybe they will decide that the Intelliflo VSF or Intelliflo XF would be a better choice.

If you're sure that you are definitely getting the Intelliflo 3, then it should not be a problem.

You also have to make sure that there are no other possible loads that you might want to add later like a booster pump for a pressure side cleaner like a Polaris booster pump (6.4 amps at 230 volts) or some other high load piece of equipment.

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Note that it is 11.2 amps if you truly have 230 volts at the pump. You can have a voltage drop for various reasons that delivers less than 230 volts at the pump. If you have 208 volts you will pull 12.4 amps.
 

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