What's considered "convenience receptacle"?

[Strathead]

That would be ideal. Unfortunately, they don't always know what every receptacle is for. And, it would be time consuming to request that of lets say 600 receptacles. I was just looking for a way to do it myself based off of the NEC's definition of convenience receptacle. But, there doesn't seem to be one.

You are making it way too difficult. I understand, that it isn't as simple as Cowboy states, but I think he missed the fact that you are asking from an Engineer/designer perspective, not an Electrician, but what I told you has NOTHING to do with requesting what 600 receptacles are for. If you have a large facility you used 600 receptacles that is probably about 30,000 square feet. Say it is an office. Ask are any offices designated for special use? I see 2 break rooms, what appliances do you anticipate? What kind of machinery do you currently use in your mail room? Do you expect to use any large copy machines outside the mail room and if so where? Look at the Architectural. Rooms will or should already be designated. So, if you see a special room ask about it. Cold Storage... Oh yeah, that is for 3 freezers, because our salesmen bring iced drug samples to our customers for example. Worry only about those items! make sure there is enough power for them, count the rest and use 180va and viola you are done. It is not that complicated, don't make it so.

 

[renosteinke]

You're all so close to the trees you can't see the forest.

Back up ... how do we determine the ampacity of a circuit? Well, we look at the loads, do some math, and - voila! - there's the breaker size we need. Then we look up the wire size ....

UNLESS we're doing a circuit for 'convenience' receptacles. That's a circuit where we don't know the loads, but the code wants us to put in the receptacles anyway. Then we have those common 'rules of thumb' for wire sizes and breaker sizes.

The "other" kind of circuit is the 'individual branch circuit, or a circuit dedicated to a specific load. For the most part, if a circuit has more than one receptacle, it's considered as a 'convenience' circuit.

So ... look at it this way .... if you plug your 60W table lamp into an individual branch circuit - a circuit just for that lamp - code calls for #14 and a 1-amp breaker. Plug that same lamp into a 'convenience' circuit, and you can find yourself using #12 on a 20-amp breaker.

 

[cppoly]

You are making it way too difficult. I understand, that it isn't as simple as Cowboy states, but I think he missed the fact that you are asking from an Engineer/designer perspective, not an Electrician, but what I told you has NOTHING to do with requesting what 600 receptacles are for. If you have a large facility you used 600 receptacles that is probably about 30,000 square feet. Say it is an office. Ask are any offices designated for special use? I see 2 break rooms, what appliances do you anticipate? What kind of machinery do you currently use in your mail room? Do you expect to use any large copy machines outside the mail room and if so where? Look at the Architectural. Rooms will or should already be designated. So, if you see a special room ask about it. Cold Storage... Oh yeah, that is for 3 freezers, because our salesmen bring iced drug samples to our customers for example. Worry only about those items! make sure there is enough power for them, count the rest and use 180va and viola you are done. It is not that complicated, don't make it so.

That is a good point. Basically look for the rooms that would have the special equipment. All this equipment gets no demand factor though right?

But how about demand factor for everything else?

One thing I remember from one of Mike Holt's service calculations examples was that he considered PC receptacles to have no demand factor. With 200 receptacles @ 360 VA per outlet to have no demand factor at 72,000 VA. So these aren't considered convenience outlets.

If PCs outlets aren't considered convenience outlets, then everything else can be considered convenience then?

And only convenience get the first 10,000 kVA 100% everything else 50%.

 

[Strathead]

That is a good point. Basically look for the rooms that would have the special equipment. All this equipment gets no demand factor though right?

But how about demand factor for everything else?

One thing I remember from one of Mike Holt's service calculations examples was that he considered PC receptacles to have no demand factor. With 200 receptacles @ 360 VA per outlet to have no demand factor at 72,000 VA. So these aren't considered convenience outlets.

If PCs outlets aren't considered convenience outlets, then everything else can be considered convenience then?

And only convenience get the first 10,000 kVA 100% everything else 50%.

I wonder, was the "PC receptacle" a fourplex? That would be 2 duplex at 180va each or a total of 360 for the outlet. Otherwise, in normal situations, you don't know how many are actually going to get computers, and it will average out. I will step in it here and say that ultimately you want to make sure that the feeder size is large enough to handle the power requirements now and in to the forseeable future. Branch circuits are less critical, because another can always be pulled. Look at what I pointed out earlier regarding a typical office. If you are providing power for a on line ordering center, for example, then you are going to know it and you will certainly account for the large quantities of computer stations. You just need to worry about the forest not the trees as renosteinke put it.