Mini Split wiring question

Reply

  #1  
Old 06-14-15, 09:08 PM
T
Member
Thread Starter
Join Date: Jan 2011
Location: US
Posts: 33
Received 0 Votes on 0 Posts
Mini Split wiring question

My mini split wire tag is attached.
I was thinking 10 gauge romex with a 30 amp breaker to an outdoor disconnect. Is this correct?

If so, do I need a certain type of disconnect? fused, breaker, switch etc?

The unit came packaged with a 6ft length of 16gauge stranded with a hot neut grnd colors so I guess thats to power from the disconnect to the outdoor unit.
Seems small for 17 amps.

Please let me know if you need more info

Edit: I will run romex from my basement subpanel outside in conduit to the disconnect.

Name:  Screenshot_2015-06-14-23-54-14.jpg
Views: 1810
Size:  23.0 KB
 

Last edited by Themow; 06-14-15 at 09:38 PM.
Sponsored Links
  #2  
Old 06-14-15, 09:58 PM
ray2047's Avatar
Member
Join Date: Mar 2006
Location: USA
Posts: 33,597
Received 13 Votes on 11 Posts
I will run romex from my basement subpanel outside in conduit to the disconnect.
Romex is not rated for use in conduit outside.
If so, do I need a certain type of disconnect? fused, breaker, switch etc?
30 or 60 amp unfused disconnect.
The unit came packaged with a 6ft length of 16gauge stranded with a hot neut grnd colors so I guess thats to power from the disconnect to the outdoor unit.
Seems small for 17 amps.
Fixture wire is not rated in the same way as "house" wire. rating is based on insulation temperature rating and specific use.
 
  #3  
Old 06-15-15, 05:16 AM
pcboss's Avatar
Forum Topic Moderator
Join Date: Jul 2002
Location: Maryland
Posts: 15,144
Received 85 Votes on 73 Posts
You can use #12 to feed the unit. As Ray already said, do not use NM. You could use UF cable or individual conductors in conduit.
 
  #4  
Old 06-15-15, 08:51 AM
T
Member
Thread Starter
Join Date: Jan 2011
Location: US
Posts: 33
Received 0 Votes on 0 Posts
Ok Thanks for the replies.
So is this the right combo?

30 Amp breaker
12/2 UF
30 or 60 amp unfused disconnect. Any thing wrong with fused? Just curious
Will this work?
Shop Eaton 30-Amp Fusible Metallic Disconnect at Lowes.com

Does the control wire from the indoor unit to the outdoor unit need to be in flexible conduit?
 
  #5  
Old 06-15-15, 09:04 AM
pcboss's Avatar
Forum Topic Moderator
Join Date: Jul 2002
Location: Maryland
Posts: 15,144
Received 85 Votes on 73 Posts
There is no need for fuses. They are not needed and you would need to keep spares if they would to blow or not have A/C. They should not blow, but could. The fusible is probably more expensive than the pullout disconnect also.
 
  #6  
Old 06-16-15, 07:08 AM
CasualJoe's Avatar
Member
Join Date: Jan 2010
Location: United States
Posts: 10,645
Received 85 Votes on 75 Posts
A non-fusible disconnect would be less than half the cost of the fusible disconnect you selected when you factor in the cost of fuses.

Shop Eaton 60-Amp Non-Fusible Metallic Disconnect at Lowes.com
 
  #7  
Old 06-16-15, 08:47 AM
pcboss's Avatar
Forum Topic Moderator
Join Date: Jul 2002
Location: Maryland
Posts: 15,144
Received 85 Votes on 73 Posts
I think the last pullout i bought was like $6.
 
  #8  
Old 06-18-15, 08:45 AM
T
Member
Thread Starter
Join Date: Jan 2011
Location: US
Posts: 33
Received 0 Votes on 0 Posts
Thank you all for the replies and help
 
  #9  
Old 06-21-15, 05:14 AM
A
Member
Join Date: Mar 2014
Posts: 547
Received 14 Votes on 14 Posts
30 Amp breaker
12/2 UF
30 or 60 amp unfused disconnect. Any thing wrong with fused? Just curious
Will this work?
#12 on a 30amp breaker? Should this not be #10 on a 30amp breaker?
 
  #10  
Old 06-21-15, 05:36 AM
pcboss's Avatar
Forum Topic Moderator
Join Date: Jul 2002
Location: Maryland
Posts: 15,144
Received 85 Votes on 73 Posts
#12 is fine. Your load is 17 amps. The breaker is to allow the unit to start. The conductors are sized to the run load.
 
  #11  
Old 06-21-15, 05:41 AM
A
Member
Join Date: Mar 2014
Posts: 547
Received 14 Votes on 14 Posts
#12 is fine. Your load is 17 amps. The breaker is to allow the unit to start. The conductors are sized to the run load.
Thank you for that info. Nice to know. But could #10 still be used without problem?
 
  #12  
Old 06-21-15, 05:50 AM
pcboss's Avatar
Forum Topic Moderator
Join Date: Jul 2002
Location: Maryland
Posts: 15,144
Received 85 Votes on 73 Posts
You can use larger if you like, but there is no need to.
 
  #13  
Old 06-21-15, 06:01 AM
A
Member
Join Date: Mar 2014
Posts: 547
Received 14 Votes on 14 Posts
You can use larger if you like, but there is no need to.
Thanks, nice to know for the future.
 
  #14  
Old 06-21-15, 05:55 PM
CasualJoe's Avatar
Member
Join Date: Jan 2010
Location: United States
Posts: 10,645
Received 85 Votes on 75 Posts
#12 on a 30amp breaker? Should this not be #10 on a 30amp breaker?
PCboss is correct. The rules are different when a motor is involved and that's all the compressor load is, a motor.

Look again at the unit data plate, it says "Max. Fuse - 30 amps". Some inspectors will go so far as to require a fusible disconnect with 30 amp fuses in a case like this, but if the plate says "MOCP - 30 amps", either a 30 amp fuse or 30 amp circuit breaker will be sufficient.
 
  #15  
Old 06-22-15, 01:24 AM
A
Member
Join Date: Mar 2014
Posts: 547
Received 14 Votes on 14 Posts
Thanks for the info CasualJoe; will keep it in mind. If using a fused disconnect would it be best to use slow blow fuses in this case or not needed because of the size requirement of the 30amp fuse which is taking into consideration the up-surge of the initial starting of the motor load?
 
  #16  
Old 06-22-15, 09:04 AM
ray2047's Avatar
Member
Join Date: Mar 2006
Location: USA
Posts: 33,597
Received 13 Votes on 11 Posts
A/Cs should always be on slow blow but you do not need to use fuses so just don't.
 
  #17  
Old 06-22-15, 11:12 AM
CasualJoe's Avatar
Member
Join Date: Jan 2010
Location: United States
Posts: 10,645
Received 85 Votes on 75 Posts
If using a fused disconnect would it be best to use slow blow fuses in this case or not needed because of the size requirement of the 30amp fuse which is taking into consideration the up-surge of the initial starting of the motor load?
Unless the AHJ requires a fused disconnect, I'd never use one. A non-fusible 60A disconnect only costs around $6. If using fuses, yes, always use the time delay type fuses for a motor load.
 
  #18  
Old 06-22-15, 01:12 PM
A
Member
Join Date: Mar 2014
Posts: 547
Received 14 Votes on 14 Posts
Thanks CasualJoe and ray2047.
 
Reply
Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off


Thread Tools
Search this Thread
 
Ask a Question
Question Title:
Description:
Your question will be posted in: