AC unit multi family
- Thread starter MBLES
- Start date
- Status
- Location
- Chapel Hill, NC
- Occupation
- Retired Electrical Contractor
Do you mean FLA--= 40.8? I believe you are trying to find the feeder size and not the branch circuit. Is that correct?
- Location
- Chapel Hill, NC
- Occupation
- Retired Electrical Contractor
Take a look at this
Mouser
Member
- Location
- Riverside, CA.
Multifamily...
My first question is:
with your plan to run one set of conductors to ALL of the AC units, which multifamily unit get to pay for the three other families AC bill?
Normally we run a circuit from each units panel to each condenser unit and the conductor sizes are based on the MCA on the units nameplate.
But then again it's Friday and I could have misinterpreted your OP.
My first question is:
with your plan to run one set of conductors to ALL of the AC units, which multifamily unit get to pay for the three other families AC bill?
Normally we run a circuit from each units panel to each condenser unit and the conductor sizes are based on the MCA on the units nameplate.
But then again it's Friday and I could have misinterpreted your OP.
- Location
- Chapel Hill, NC
- Occupation
- Retired Electrical Contractor
I was confused also. If he wants a branch circuit then why would he be adding all 4 together. The branch circuit for each would usually be marked on the unit as MCA or minimum circuit ampacity
Sorry I was thinking of another job with a similar problem. I found answer upon reading other similar post.
Yes Sir The Feeder Size is what I am looking for Its basically a chiller feeder that has 4 condenser units FLA 40,8 a and 5.3 fan motor.. Name plate MCA 194.6 and MOCP 225a. IS the feeder sized by the 194.6 on name plate? do i add the 125% to get feeder size? or just use whats on name plate MCA 194.6amps to find size wire needed. The name plate also limits the OCPD to MOCP 225. The job is an all bills paid apartments.
jumper
Senior Member
- Location
- 3 Hr 2 Min from Winged Horses
You just follow the nameplate. No additional math needed.
3/0 CU or 250 AL and a 225A breaker.
What would you do for a disconnect at HVAC? is there a 225 main breaker disconnect rated for HVAC? just curious
jumper
Senior Member
- Location
- 3 Hr 2 Min from Winged Horses
Safety switch would be more common IME.
200a or 400a ?
jumper
Senior Member
- Location
- 3 Hr 2 Min from Winged Horses
400A
kwired
Electron manager
- Location
- NE Nebraska
225 amp breaker might be less $$ than a 400 amp safety switch.
200 amp non fused safety switch might be rated for the overall HP rating also even if on higher than 200 amp overcurrent device ahead of it.
jumper
Senior Member
- Location
- 3 Hr 2 Min from Winged Horses
Me just follow prints/specs....
kwired
Electron manager
- Location
- NE Nebraska
Nothing wrong with that, but some have to design a lot of what they install.
JoeStillman
Senior Member
- Location
- West Chester, PA
Me just draw those prints/specs.
I still always call for a fused disconnect for all refrigeration equipment. There are two good reasons; even though your mechanical department might have specified a unit listed for use with a fuse or HACR breaker, the successful bidder might win the job with a substitution that is rated with fuse only. Secondly, if the equipment branch circuit is short, you might exceed the (typical) 5 kAIC rating. With a fusible switch on-site, you've got a fighting chance of getting a current-limiting fuse that protects the under-duty equipment.
Anyone else here insist on fusible disconnects for all refrigeration equipment?
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