125% of largest motor

[augie47]

In the past few months i have completed two courses on Residential Load Calculations. Although both contained much of the same info, I noted one emphasized a step adding 125% of the largest motor load to the final calculation whereas it is not mentioned in the other.
In looking at MH calculation tools I don't see that 125% figure. Has anyone noted form testing if such a number should be included when calculating load ?

 

[dkidd]

I have seen it as a requirement from a number of utility companies.

 

[Smart $]

In the past few months i have completed two courses on Residential Load Calculations. Although both contained much of the same info, I noted one emphasized a step adding 125% of the largest motor load to the final calculation whereas it is not mentioned in the other.
In looking at MH calculation tools I don't see that 125% figure. Has anyone noted form testing if such a number should be included when calculating load ?

The extra 25% for the largest motor is actually required under standard calculation. It seems many, including AHJ's, overlook it in residential calculations... especially if the motor is part of an appliance.

 

[jumper]

Many times the HVAC contains the largest motor and when it is calculated at 125% and 220.50/430.24 is satisfied.

Problem is that it is not always stated clearly by authors.