Breaker or Disconnect For Wire Size

Status
Not open for further replies.
M

mstrlucky74

Senior Member
Location
NJ
Have a panel schedule that shows the breaker for a AC unit to be "trip Amps" 40/2. The disconnect is a 2p/60a. What should I size the wire to and why? I'm thinking 2 #6 w/#8G. Thanks.
 
luckylerado

luckylerado

Senior Member
Location
Lake of the Ozarks
mstrlucky74 said:
Have a panel schedule that shows the breaker for a AC unit to be "trip Amps" 40/2. The disconnect is a 2p/60a. What should I size the wire to and why? I'm thinking 2 #6 w/#8G. Thanks.
Click to expand...

I would size to 40 amp <with voltage drop if stated or otherwise obligated> on the estimate and verify against the actual equipment product data as soon as it becomes a known before committing to pipe and wire size in the field. HAVC equipment manufacture/model/size can often change from what is in the design package.
 
roger

roger

Moderator
Staff member
Location
Fl
Occupation
Retired Electrician
mstrlucky74 said:
Have a panel schedule that shows the breaker for a AC unit to be "trip Amps" 40/2. The disconnect is a 2p/60a. What should I size the wire to and why? I'm thinking 2 #6 w/#8G. Thanks.
Click to expand...

If you had a 200 amp panelboard would you size every branch circuit conductor at 3/0?

Roger
 
infinity

infinity

Moderator
Staff member
Location
New Jersey
Occupation
Journeyman Electrician
mstrlucky74 said:
Have a panel schedule that shows the breaker for a AC unit to be "trip Amps" 40/2. The disconnect is a 2p/60a. What should I size the wire to and why? I'm thinking 2 #6 w/#8G. Thanks.
Click to expand...

I've never seen the term "trip amps" used in any context. From the info provided you cannot accurately determine the conductor size. For 40 "trip amps" it could be #12 AWG.
 
Jraef

Jraef

Moderator, OTD
Staff member
Location
San Francisco Bay Area, CA, USA
Occupation
Electrical Engineer
bsmith8691 said:
A fair amount of the A.C. units I have wired state in the name plate information minimum circuit ampacity/ max fuse size.

Sent from my XT1254 using Tapatalk
Click to expand...
That's a good point. You must go with the LIAD information to size your conductors and fuse/CB, not the panel schedule. If someone only gave you a panel schedule and no info on the load, then you must go with the breaker size they are providing, but get it in writing that this may or may not meet code and will need to be changed, via change order, if the circuit is under sized.
 
Status
Not open for further replies.
Top