what demand % do I use?

[JFletcher]

Typically, how many home runs would go to each room? The hotels Ive seen have 2-4; older ones, one 240/277V line to the PTAC, one to the room. Newer have the PTAC, one to the room, one to the bathroom, and the 4th would be for a built-in microwave.

 

[Grouch]

Technically, any receptacle that is not for a specific purpose. And though some may seem to have a specific purpose, they are still general-purpose receptacles because the utilization equipment that seems to make them specific purpose can be readily plugged in somewhere else.

Smart $, even if a receptacle is dedicated (one receptacle on its own breaker) to a refrigerator or similar equipment, it's still considered general use? Sorry to keep asking... as we've all experienced with codes, one word can change everything!

 

[Grouch]

Typically, how many home runs would go to each room? The hotels Ive seen have 2-4; older ones, one 240/277V line to the PTAC, one to the room. Newer have the PTAC, one to the room, one to the bathroom, and the 4th would be for a built-in microwave.

Usually, on other hotel projects i've been involved with (without refrigerators / coffee makers), each room would have 4 circuits: one circuit for the PTAC, one circuit for the bathroom receptacle, one circuit for the lights and switched receptacles, and one circuit for the remainder of the receptacles that are always hot.

 

[JFletcher]

Usually, on other hotel projects i've been involved with (without refrigerators / coffee makers), each room would have 4 circuits: one circuit for the PTAC, one circuit for the bathroom receptacle, one circuit for the lights and switched receptacles, and one circuit for the remainder of the receptacles that are always hot.

Thanks. I forgot the other major load a room sees everyday: the housekeeper's vacuum. That the bathroom receptacle is basically a dedicated circuit would indicate to me most hotels supply hairdryers, or plan for them to be used anyway.

The hotel I used to work at had one wing with switched receptacles for a floor lamp; the others had sconces and no switched receptacle. Tho I've done many hotels, it was always the v/d/v, so I wasnt sure what was 'standard' for home runs on the electrical side.

 

[Smart $]

Smart $, even if a receptacle is dedicated (one receptacle on its own breaker) to a refrigerator or similar equipment, it's still considered general use? Sorry to keep asking... as we've all experienced with codes, one word can change everything!

Code uses the terminology of individual branch circuit for a dedicated receptacle. Being for a refrigerator would likely make it a specific purpose receptacle (yet in a dwelling kitchen it is not). If by chance the need for a refrigerator is removed (as is the refrigerator), then the receptacle becomes general use. There is no hard line as far as the wiring goes.

It amounts to the intended use at the time it is being assessed. And parameters can make a difference. For example, when in a dwelling vs. non-dwelling; a full-size refrigerator vs. a mini. Also, just because something can conveniently be plugged into a certain receptacle does not make it a specific purpose receptacle... but if the receptacle is placed there specifically for the purpose of plugging in certain equipment, you have to make a choice.

 

[Grouch]

Code uses the terminology of individual branch circuit for a dedicated receptacle. Being for a refrigerator would likely make it a specific purpose receptacle (yet in a dwelling kitchen it is not). If by chance the need for a refrigerator is removed (as is the refrigerator), then the receptacle becomes general use. There is no hard line as far as the wiring goes.

It amounts to the intended use at the time it is being assessed. And parameters can make a difference. For example, when in a dwelling vs. non-dwelling; a full-size refrigerator vs. a mini. Also, just because something can conveniently be plugged into a certain receptacle does not make it a specific purpose receptacle... but if the receptacle is placed there specifically for the purpose of plugging in certain equipment, you have to make a choice.

Thanks for the 'IBC' terminology... I went to the definitions section of the NEC for individual branch circuits... and right above it was the definition for general purpose branch circuits! I was looking for that before and couldn't find it! So general purpose is defined as 2 or more receptacles for lighting and appliances. That being said, since the refrigerator and coffee maker receptacles will be on dedicated circuits (as of now they are dedicated, since we have no cuts of the equipment), they are IBC's instead of general purpose... which means I shouldn't be using 220.14(J) since these are not general purpose circuits... which means I should follow 220.14(I) and then take the demand factor from Table 220.44. Would that be the correct method / thinking to follow?

 

[Smart $]

Thanks for the 'IBC' terminology... I went to the definitions section of the NEC for individual branch circuits... and right above it was the definition for general purpose branch circuits! I was looking for that before and couldn't find it! So general purpose is defined as 2 or more receptacles for lighting and appliances. That being said, since the refrigerator and coffee maker receptacles will be on dedicated circuits (as of now they are dedicated, since we have no cuts of the equipment), they are IBC's instead of general purpose... which means I shouldn't be using 220.14(J) since these are not general purpose circuits... which means I should follow 220.14(I) and then take the demand factor from Table 220.44. Would that be the correct method / thinking to follow?

Nothing wrong with thinking that way. But yet on the other hand there is nothing wrong with calculating these IBC's under 220.14(J) either. You have to remember the definitions referred to are for the circuit... not the receptacles themselves. A full-size 15A IBC for a dwelling unit refrigerator in the kitchen is required to be an SABC... which is permitted to be "absorbed" by the general lighting load... but doesn't mean it has to be. Then regarding the coffee maker. I doubt anyone else would put it on an IBC let alone consider it a specific purpose receptacle. I don't believe we're talking about a restaurant-level coffee maker that'll serve hundreds in a matter of hours... just a one to few cup maker, right?

A consideration for how you calculate these receptacles is that you must calculate lighting load at 2 VA/ft². How much will the actual connected VA be? What's the difference? Will the difference "absorb" the receptacle load?

Do you want to calculate conservatively, not, or in between. If you can manage to get some first-hand, real load records and compare to calculated, you'd have a better idea of just exactly how conservative the NEC calculation paradigm is.

 

[Grouch]

Nothing wrong with thinking that way. But yet on the other hand there is nothing wrong with calculating these IBC's under 220.14(J) either. You have to remember the definitions referred to are for the circuit... not the receptacles themselves. A full-size 15A IBC for a dwelling unit refrigerator in the kitchen is required to be an SABC... which is permitted to be "absorbed" by the general lighting load... but doesn't mean it has to be. Then regarding the coffee maker. I doubt anyone else would put it on an IBC let alone consider it a specific purpose receptacle. I don't believe we're talking about a restaurant-level coffee maker that'll serve hundreds in a matter of hours... just a one to few cup maker, right?

A consideration for how you calculate these receptacles is that you must calculate lighting load at 2 VA/ft². How much will the actual connected VA be? What's the difference? Will the difference "absorb" the receptacle load?

Do you want to calculate conservatively, not, or in between. If you can manage to get some first-hand, real load records and compare to calculated, you'd have a better idea of just exactly how conservative the NEC calculation paradigm is.

Valid point... the definitions refer to the circuit breakers, not the receptacles. Eventually I'll decide which route to take... thanks so much for the help. And yes, it's probably only a small coffee maker, so making that a dedicated circuit might be overkill.

Yeah, i'm aware that the actual load records are sometimes nowhere near what we calculate for. I've realized that on some tenant fit-out projects I've worked on in the past. The NEC calculations are conservative... which means I shouldn't worry about the end result being too small... sometimes I still worry though :happyyes::happysad: