Replace 30 Amp with 45 Amp AC Condenser

Reply

  #1  
Old 07-09-05, 07:54 AM
djc621
Visiting Guest
Posts: n/a
Replace 30 Amp with 45 Amp AC Condenser

Hello all!

I am replacing my AC condenser (on my roof), going from a 30 AMP to a 45 AMP. Here is the name plate data: 60 Hz, 1Phase, 197 Min Volatage. Max Fuse or Breaker -45. Min Ckt Ampacity 33.1.

My question has to do with guage/size of wiring and what size breaker . I've had two different suggestions for wiring (8 and 6) and two suggestions for breakers - 60 and 45. It seems to me that the breaker should be 45 per the plate. As for wiring, I'm not sure whether 8 0r 6 is correct and how many wires need to go from the breaker panel ( I have to go through the ceiling and into a conduit up to the roof). Any clarifications and suggestions will be greatly appreciated!
 
Sponsored Links
  #2  
Old 07-09-05, 08:06 AM
Member
Join Date: Feb 2002
Location: port chester n y
Posts: 2,117
Install two #8 THHN conductors protected by a 50-amp 2-pole C-B.

DO NOT USE WHITE OR GREEN CONDUCTORS!!!!!---- You MAY need a Green Equiptment Grounding Conductor IF the Wiring Method between the dis-connect and the compressor equiptment, or the Wiring Method between the panel and the dis-connect, does not provide a Grounding path.This

Also, check the rating of the existing dis-connecting means.

Good Luck & Enjoy the Experience!!!!!!!!11
 
  #3  
Old 07-09-05, 08:17 AM
djc621
Visiting Guest
Posts: n/a
Thanks!

Thanks for bring up the subject of the disconnect! Sould it be replaced (exisitng 30 fuseable) with a 45 or a 60 amp disconnect? Thanks again!
 
  #4  
Old 07-09-05, 08:33 AM
djc621
Visiting Guest
Posts: n/a
Disconnect

Thanks again for the reply. Let me clarify my question on the disconnect. Should I go with a 45 or a 60 (I didn't see 45 in the store) and should it be fuseable (non automatic) or automatic? If there is a way not to have to run a ground wire that would be better beczause the exisiting conduit runs inside the ceiling and is not easily accessible. I have to try to pull the new wire through using the old so I didn't want to add more. I can't tell whether the exisitng wire is already sufficient. The only marking is 600V on the red wire
(1 wire from the main panel to the disconnect). There are also two narrower black wires and one larger black wire coming into the disconnect. Thanks again and if you have a suggestion on the disconnect - how to avoid running the ground wire (or if one of the existing is already a ground) let me know. Thanks again!
 
  #5  
Old 07-09-05, 08:50 AM
Member
Join Date: Feb 2002
Location: port chester n y
Posts: 2,117
As to the required Equiptment Grounding Conductor between the panel and the dis-connect, you will have to indenify the type of existing Wiring Method. IF the existing W-M is 1/2" or 3/4" Electical Metallic Tubing, properly installed, then pull in 2 #8 Black THHN conductors and a #12 Green EGC.

I suggest a dis-connect rated at 60 amps---will provide more wiring space. If you use an "all-plastic" liquid-tite flex between the Dis-connect and the compresor, you MUST have an EGC in the flex.
 
  #6  
Old 07-09-05, 09:23 AM
djc621
Visiting Guest
Posts: n/a
Many Thanks!

You've been a great help!
 
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
Display Modes
'