New hotel in Mc What would you do?

[shockare]

new job starting soon,

Its a 3 storie hotel, with a 100 rooms
wood frame tgi and truss
each room needs 5- 20 amp ckts,
2 for lights 1 for p-tack 1 for gfci and 2 for outlets
33 rooms per floor
No cooking
each room must have a "master lighting disconnect switch"



Looking for the best answer for mc cable.
I would like to cut down the number of homeruns from 160
to avoid a huge bundle/ derateing above main hallway ceilings
back to panel room

If i run 2- 12/3's and 1-12/2 per room
with 2-2p 20 amp breakers and 1 1p breaker
adding time pigtailing the grounded conductor

0r run 2-12/4's and 1-12/2 per room with no time adding the tails
and have choice of breakers 1p or 2p seeing that i an not shareing a grounded conductor
landing each conductor of the same cable on the same phase hence not a true multiwire branch ckt
or am i bound to use a breaker tie for all for poles with the use of 12/4 mc cable?

And yes i would have liked to pipe back to Mech room meaning more fun derateing and time
At the job meeting today ( unable to make)
AHj inspector called for today Arc faults that will be tomorrows battle of 210.12


what would you do?

 

[kwired]

new job starting soon,

Its a 3 storie hotel, with a 100 rooms
wood frame tgi and truss
each room needs 5- 20 amp ckts,
2 for lights 1 for p-tack 1 for gfci and 2 for outlets
33 rooms per floor
No cooking
each room must have a "master lighting disconnect switch"



Looking for the best answer for mc cable.
I would like to cut down the number of homeruns from 160
to avoid a huge bundle/ derateing above main hallway ceilings
back to panel room

If i run 2- 12/3's and 1-12/2 per room
with 2-2p 20 amp breakers and 1 1p breaker
adding time pigtailing the grounded conductor

0r run 2-12/4's and 1-12/2 per room with no time adding the tails
and have choice of breakers 1p or 2p seeing that i an not shareing a grounded conductor
landing each conductor of the same cable on the same phase hence not a true multiwire branch ckt
or am i bound to use a breaker tie for all for poles with the use of 12/4 mc cable?

And yes i would have liked to pipe back to Mech room meaning more fun derateing and time
At the job meeting today ( unable to make)
AHj inspector called for today Arc faults that will be tomorrows battle of 210.12


what would you do?

No sub panels located closer to loads to cut down on copper used for home runs? Seems like a good idea to me.

Otherwise if you have 3 phase why not use all three phases with your MWBC's. You will need handle ties or 3 pole breakers.

No cooking - sounds to me like this means no dwelling units are involved which also means no AFCI is required. Tell inspector to read 210.12 and 210.18.

 

[bullheimer]

for that battle look at Codes definition of Dwelling Unit. says must have cooking. but have fun. i am with kwired, i would have a sub panel on each floor, or, like another building i've seen, one on each end of each hall. 17 rooms on each.

on the two pole bkrs, i believe you do NOT need them unless two hots are sharing a neut.

 

[kwired]

for that battle look at Codes definition of Dwelling Unit. says must have cooking. but have fun. i am with kwired, i would have a sub panel on each floor, or, like another building i've seen, one on each end of each hall. 17 rooms on each.

on the two pole bkrs, i believe you do NOT need them unless two hots are sharing a neut.

They don't have to be two pole breakers, handle ties are acceptable if it is a MWBC.

If the system is 208/120, you don't get to take advantage of not counting the neutral of two pole MWBC's as non current carrying conductors though so there will be more current carrying conductors in your raceways if you have multiple circuits in a raceway. If you use three pole MWBC'c then the neutral is not considered a current carrying conductor for ampacity adjustments.

 

[G._S._Ohm]

I'd list all possibilities (this is not as easy as it sounds) and then price them out.

You may find some minimum cost or minimum labor hours weet spot for doing this.

 

[cdslotz]

I'm not sure I ever bid a hotel without any specs provided.

Is this a "roll your own" design/build?

 

[Smart $]

...1 for p-tack...

What's a p-tack?

...2 for lights...
each room must have a "master lighting disconnect switch"

Will handle-tied, switch-rated breakers in panelboard suffice? Even if wall switched, run as mwbc.


Why a master lighting disconnect for each room? To turn off lighting when room is supposed to be unoccupied?

...
0r run 2-12/4's and 1-12/2 per room with no time adding the tails
and have choice of breakers 1p or 2p seeing that i an not shareing a grounded conductor
landing each conductor of the same cable on the same phase hence not a true multiwire branch ckt
or am i bound to use a breaker tie for all for poles with the use of 12/4 mc cable?
...

Don't forget you can bundle up to 20ccc's (20A, #12 Cu) with non-jacketed MC and not have to derate for number of ccc's, as long as there is not more than 3ccc's per cable.

 

[stevebea]

new job starting soon,

Its a 3 storie hotel, with a 100 rooms
wood frame tgi and truss
each room needs 5- 20 amp ckts,
2 for lights 1 for p-tack 1 for gfci and 2 for outlets
33 rooms per floor
No cooking
each room must have a "master lighting disconnect switch"



Looking for the best answer for mc cable.
I would like to cut down the number of homeruns from 160
to avoid a huge bundle/ derateing above main hallway ceilings
back to panel room

If i run 2- 12/3's and 1-12/2 per room
with 2-2p 20 amp breakers and 1 1p breaker
adding time pigtailing the grounded conductor

0r run 2-12/4's and 1-12/2 per room with no time adding the tails
and have choice of breakers 1p or 2p seeing that i an not shareing a grounded conductor
landing each conductor of the same cable on the same phase hence not a true multiwire branch ckt
or am i bound to use a breaker tie for all for poles with the use of 12/4 mc cable?

And yes i would have liked to pipe back to Mech room meaning more fun derateing and time
At the job meeting today ( unable to make)
AHj inspector called for today Arc faults that will be tomorrows battle of 210.12


what would you do?

Is there only one mechanical room? Alot of the 3 story hotels we do will have electrical rooms stacked one each floor.

 

[stevebea]

What's a p-tack?


A PTAC unit is a thru wall heating and cooling unit commonly used in hotels.

 

[ptcrtn]

run MC home run cable to each room 12/8c black, black/silver, red, red/silver, blue, blue/silver, white, white/silver,green
12AWG, 90?C = 30 amperes derating factor 8 conductor 70% 30x.70=21

 

[shockare]

thanks for all the replies

Yes it is a kind of "roll your own design" get it done yesterday and cheap

I tried to get Subs in place on each wing but got shot down
wiring method is up to me, and p tack is a slang for an under window heat/ ac combo unit

The master lighting switch is something the ahj threw in as a way of "going green"
so that the the lighting will be off when the room is unoccupied .

Made no sense to me, if you cant turn 1 switch off what makes you think someone would turn the master off? This switch should be controlled from the front desk at check out time.

 

[Smart $]

run MC home run cable to each room 12/8c black, black/silver, red, red/silver, blue, blue/silver, white, white/silver,green
12AWG, 90?C = 30 amperes derating factor 8 conductor 70% 30x.70=21

As long as you don't stack or bundle more than 20ccc's (4 cables at 6ccc per cable). More than 20ccc's are derated 60%. Using 12/8 you can get up to 6 circuits 120V3?4W mwbc's (note OP said 5 circuits then itemized 6). Two 3-pole handle-ties required.

 

[Cow]

I would lean towards two 12-4's with individual neutrals on 1000' reels. We used this in a school recently, seemed to work pretty good. Take each one to a homerun box in the room and branch out. Only two cables per room would really cut down on the runs back to the panel.

 

[Fulthrotl]

thanks for all the replies

Yes it is a kind of "roll your own design" get it done yesterday and cheap

I tried to get Subs in place on each wing but got shot down
wiring method is up to me, and p tack is a slang for an under window heat/ ac combo unit

The master lighting switch is something the ahj threw in as a way of "going green"
so that the the lighting will be off when the room is unoccupied .

Made no sense to me, if you cant turn 1 switch off what makes you think someone would turn the master off? This switch should be controlled from the front desk at check out time.

there is a pretty cool device i'd sell hard here....

it's a smart plug that ties with an occupancy sensor on the ceiling, and a door trip.

when the room is unoccupied, AC is set for 82 or so (t stat in occupancy sensor on ceiling
cycles AC on and off at 82)

when you walk into the room, opening the door switches on the AC, and the normal set
point of the AC is maintained while the room is occupied. occupancy sensor is over bed
in center of room.

it's all wireless. the smart plug feeds the AC, and you can tie lights into it as well, so when the
room is unoccupied, the lights are off... as soon as the door opens, the lights go on.

i can't remember the name of the company making it, but if you are interested, i'll call
my wholesale house in the morning and get you some info... i happened to be in there
when the salesman walked in.... drops power consumption about 60% in hotels.... :jawdrop:

 

[Fulthrotl]

new job starting soon,

Its a 3 storie hotel, with a 100 rooms
wood frame tgi and truss
each room needs 5- 20 amp ckts,
2 for lights 1 for p-tack 1 for gfci and 2 for outlets
33 rooms per floor
No cooking
each room must have a "master lighting disconnect switch"

what would you do?

i'd re calc this.....

how big a hotel room *is* this?

TWO 20 amp lighting circuits? you can put a lot of CFL's
on a circuit....

one 20 amp on the gfci makes sense, hotels are blow dryer
hell in the mornings

TWO convenience outlet circuits? most hotel rooms i've
been in aren't really flush on receptacles. three circuits
for two rooms is what i've seen.

i'd say, per three rooms, three receptacle circuits, two lighting
circuits, three GFCI circuits, and three AC's.

33 receptacle, 22 lighting, 33 GFCI's, and 33 AC's.

121 circuits per floor, not counting common areas, etc.

3 panels per floor @ 42 ckts each. what i have seen done
is a large mural mounted in the middle of the hallway,
so you can put three panels behind it, and a piano hinge
on one side so the thing can be swung away from the wall
to access the panels.

the large picture can be mounted on 1/2" mdf, and framed
to hide the edge of the mdf. you will never know the panels
are there. and in the center of the building, you can go both
ways with homeruns, and cut down the density.

and i'd pass on bundling them so you don't have to derate.
they make nail straps, and i'd spread them out 1" apart down
the hallways. i'd be in there as soon as the floor was framed,
pull a couple strings for the wall lines on the corridors, and
be getting all the home runs in ahead of everything else.

now, for feeders, i'd use pass thru panels, and size the
feeders accordingly.

three sets of feeders, each feeding three panels stacked
above each other.

so you are feeding the whole thing with three 4" emt, using
cup-L-taps to tap off, feeding each panel. aluminum feeders,
copper taps from the cup L taps to the main breakers in the
panels.

 

[shockare]

Thanks for the input

Thanks for the input

I know the amount of circuits for each room is over kill
Its on the specs , talk now about a back up genny for the lighting

I cant get them to budge on hallway panels ,As i figure in hall and other loads
there will be about 170 circuits running from the back of the building thru a main hallway then branch out left and right to each wing. 3x's

The farthest home runs would be close to 200 foot (not good)
Mech rooms are stacked floor to floor

As too:
"Fulthrotl
it's a smart plug that ties with an occupancy sensor on the ceiling, and a door trip."
Sounds good could be a great upsell
would you have a name of that set up? what kind of cost & time line to install?
could that unit be controlled via remote?

Ty COW that was my very thought with using 12/4

 

[kwired]

I cant get them to budge on hallway panels ,As i figure in hall and other loads
there will be about 170 circuits running from the back of the building thru a main hallway then branch out left and right to each wing. 3x's

Yet we get all these guys that complain about the price of things. I say if that is what they want then it is going to cost them.

I can understand not wanting panels in the corridors, but well placed mechanical rooms are probably worth it, for more than just electrical too.

 

[Strathead]

Another possibility... Most of the wire and cable manufacturers offer custom solutions. I count 6 circuits in your description not 5, but none the less, given that you are going to have thousands of feet of home run, I wouldnot be surprised to run the numbers and find that you can purchase master reels, of 1000' or maybe even 2500' of MC cable with all of the circuits you need in one cable. Since all of the rooms are identical home runs this would save labor on multiple levels. Make up layout, material mistakes etc.

 

[DPMin]

MC Supports

MC Supports

I used a "non-bundling MC support bracket" in a recent job. The product I used was Caddy MCS100, other manufacturers may have something as well. You can support 8 cables per support with no bundling issues (our inspector was good with them).



http://www.erico.com/products/CaddyMCS.asp

 

[Smart $]

I used a "non-bundling MC support bracket" in a recent job. The product I used was Caddy MCS100, other manufacturers may have something as well. You can support 8 cables per support with no bundling issues (our inspector was good with them).

View attachment 7856

http://www.erico.com/products/CaddyMCS.asp

Yeah, they avoid bundling issues, but stacking is also part of the derating conditions. IMO, this does not alleviate a stacking condition. What say ye all?