2 very odd questions, I thought

[Finite10]

I recall a couple odd questions that haunt me still;

1) Several motors -fused with an inverse time delay breaker. The largest motor was also 5 minute intermittent duty cycle.

Not sure if I took the largest motor at 125% and ignored the 110% intermittent duty deration, or not, at this point. What to do if I see this in the world?

2) Multi Family Optional. The question said no house load and no laundry.

Would that mean no additional laundry room load on the house load after totalling the units' load? Or no laundry figured in the per units' calc? Does it mean no dryer too? The dryer was not listed and not mentioned at all!

 

[Dennis Alwon]

2) Multi Family Optional. The question said no house load and no laundry.

Would that mean no additional laundry room load on the house load after totalling the units' load? Or no laundry figured in the per units' calc? Does it mean no dryer too? The dryer was not listed and not mentioned at all!

I'll reply to #2-- I think they mean that there is a central laundry area so each unit does not have to be figured for laundry load-- washer and dryer..

Not sure what no house load means other than not to figure the load for the house panel.

 

[Finite10]

That was my initial take too. But the exclusion of laundry was right after exclusion of house load. It was unclear. Actually if I recall - the more exact statement said;

'No house load and no laundry is to be be included.'

 

[Dennis Alwon]

That was my initial take too. But the exclusion of laundry was right after exclusion of house load. It was unclear. Actually if I recall - the more exact statement said;

'No house load and no laundry is to be be included.'

It sounds like they want you to calculate the load of the individual units so no common area lights, laundry etc are applicable.

 

[Finite10]

This was a Masters' Test so it should've been more clear.

220.85 Two Dwelling Units says it's OK to use 220.84 Multifamily optional.

So 220.84 (C) Connected Loads says demand Table 220.84 SHALL include...
1.
2. Two Small Appliance kitchen circuits AND one Laundry circuit
3.
4.
5.

So how could an exam question exclude something that the NEC says SHALL be included? It can't.
It looks like the exam wanted to exclude a laundry facility room and a house lighting load from the calc.

But- use Part III which says a Laundry circuit SHALL be included, and then it is permitted to be added to the General Lighting Load and DF deducted. So, I would assume that the Standard Method Part III must be used and add laundry and Dryer ckts as the NEC mandates. And I'm supposed to know that excluding Laundry load and house load really means Laundry Room Facility + House load.

 

[Jim Shorts]

220.84(C)(2) only requires a laundry circuit as covered in 210.11(C)(2) which refers you to 210.52(F) which in turn does not require a laundry circuit in a multifamily dwelling unit where laundry facilities are not permitted or central laundry facilities are provided. The laundry circuit is NOT required to be included in a multifamily dwelling load calculation if either of these conditions exist.

Says the same thing in 220.52(B) if you use the standard method for calculating loads.

 

[Finite10]

220.84(C)(2) only requires a laundry circuit as covered in 210.11(C)(2) which refers you to 210.52(F) which in turn does not require a laundry circuit in a multifamily dwelling unit where laundry facilities are not permitted or central laundry facilities are provided. The laundry circuit is NOT required to be included in a multifamily dwelling load calculation if either of these conditions exist.

I do recall flipping to 210.52(F) exc. 2. "...where laundry facilities are not to be installed or permitted..." Thanks Jim.

I included a 5KVA dryer due to 220.84(C)(3)c.
even though there was no dryer on the equipment list and laundry was to be excluded.

Tried the calc different ways and didn't match an answer selection.

 

[wawireguy]

This test is pretty much designed to make the state money. It's not designed to see if you can really do a load calculation.

Your strategy should be to ace the easy questions. Guess on the large commercial calc and give the residential load calcs your best shot.

In the motor question the intermittant part you are referring to has nothing to do with the question. Review multiple motor feeders and protection for that question.

Good luck on the resi load calcs!