# What Is the Demand Factor Allowed by the Nec for Calculating the Neutral Conductor Size for an Electric Range Load?

August 5, 2022

The minimum size required for the neutral wire is 4 AWG (see Figure 2). For household electric cookers, wall-mounted ovens, counter top cooking appliances and electric dryers, it is permissible to use a demand factor of 70 percent when calculating the feed-in or grid-neutral load.

## What NEC article provides the rules for demand factors?

Item 220 contains half a dozen demand factor tables. But you can also get an engineering exemption from the AHJ. For example, you might have 8 welding tanks in a workshop, but realistically there is only room for two welders at a time.

## What is neutral demand?

In economics, neutral goods refer either to goods whose demand is independent of income, or to those that, when consumed, produce no change in the consumer’s utility. By the first definition, neutral goods have substitution effects but no income effects.

## Are demand factors permitted in determining feeder loads?

Use of the demand factors in Table 220.54 is allowed. When two or more single phase dryers are powered from a 3 phase 4 wire feed or supply, the total load must be calculated based on twice the maximum number connected between any two phases.

## When sizing the general lighting load for electric services the first 3000va is rated at?

A demand factor as allowed in Table 220.42 can be applied to these loads. Depending on the VA, the first 3,000 VA can be charged at 100 percent and the remaining VA at 35 percent.

## What is Article 220 in the NEC?

Article 220 of the 2020 National Electrical Code (NEC) provides the requirements for calculating demand loads for branch circuits, feeders and services.

## How do you calculate electrical demand factor?

• Demand factor = maximum demand of a system / total connected load of the system.
• Demand factor is always less than one.
• Example: if there is a residence Connected 6000 W Devices have a maximum demand of 300 W, as demand factor = 6000 W / 3300 W = 55%.

## How do you size a neutral conductor NEC?

Dimensioning of the neutral conductor: Sec. 220-22. You must size the neutral wire to carry the maximum unbalanced current in the circuit (i.e. the largest load between the neutral wire and an ungrounded phase wire). They calculate the first 200 A of neutral current as 100%.

## How do you calculate neutral demand load?

The neutral load can be calculated by multiplying the maximum demand by 70 percent (25 × 70% = 17.5 kW). The neutral load for 10 12 kW household electric stoves is 17.5 kW (see Figure 4).

## How do you calculate neutral?

Note the neutral formula. If A, B and C are the three phase currents, the formula to find the neutral current is the square root of the following: (A^2 + B^2 + C^2 – AB – AC – BC).

## What is load demand factor?

: the ratio of the maximum demand during an allotted period of time on a power grid to the actual connected load during that time, usually expressed as a percentage.

## What is a feeder in the NEC?

Article 100 defines feeders as: “All circuit conductors between the service equipment, the source of a separately derived system or other power supply source and the last branch circuit overcurrent protective device.” definition to follow.

## What demand factor is allowed for a commercial kitchen with one electric appliance?

One device has a demand factor of 100%, while six or more devices have a demand factor of 65%. There is one exception to the table given in the second paragraph of NEC 220.56. The total load of the kitchen appliances must be at least as large as the sum of the two largest kitchen appliance loads.

## What are the demand factors for the general lighting load in dwellings?

One device has a demand factor of 100%, while six or more devices have a demand factor of 65%. There is one exception to the table given in the second paragraph of NEC 220.56. The total load of the kitchen appliances must be at least as large as the sum of the two largest kitchen appliance loads.

## What is the minimum general lighting load in VA per square foot required by the NEC for a store?

The NEC requires a minimum lighting load of 3 volt-amps per square foot.

## What is the minimum general lighting load in VA per square foot required by the NEC for a single family dwelling?

VA load of general lighting.

Include a minimum of 3 VA per square foot for general lighting and general purpose outlets when calculating branch circuit and supply/connector loads for residences [ 220.12].

### References:

2. https://en.wikipedia.org/wiki/Neutral_good
3. https://site.ieee.org/icps-ehe/files/2015/11/13-9-NFPA-70_-National-Electrical-Code-NEC-Article-220.pdf
4. https://www.ecmag.com/section/codes-standards/residential-calculations-estimating-elements-electrical-system
7. https://www.ecmweb.com/national-electrical-code/code-basics/article/20890526/characteristics-of-the-neutral-conductor
8. https://www.ecmag.com/section/codes-standards/branch-circuit-feeder-and-service-calculations-part-xlii
9. https://www.hunker.com/12470226/how-to-calculate-neutral-currents
10. https://www.merriam-webster.com/dictionary/demand%20factor
11. https://www.ecmweb.com/national-electrical-code/code-basics/article/20886456/article-215-feeders
12. http://www.designmaster.biz/blog/2015/12/revit-kitchen-demand-factors/
13. https://up.codes/s/general-lighting
14. https://quizlet.com/513867876/chapter-2electrical-calculations-flash-cards/
15. https://www.ecmweb.com/content/article/20886603/dwelling-unit-calculations