Outdoor condensing Unit
- Thread starter jeff1166
- Start date
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electricman2
Senior Member
- Location
- North Carolina
- Occupation
- Retired Electrical Contractor
Re: Outdoor condensing Unit
If the nameplate data specifies fuses, then you cannot use a CB. It may allow for fuses or HACR breakers in which case a breaker would be acceptable.
If the nameplate data specifies fuses, then you cannot use a CB. It may allow for fuses or HACR breakers in which case a breaker would be acceptable.
- Location
- New Jersey
- Occupation
- Journeyman Electrician
Re: Outdoor condensing Unit
Article 440 applies to AC units which permit you to use the ampacity listed in table 310.16. In this case your #12 AWG is fine for a nameplate listed minimum circuit ampacity of 21 amps. #12 THHN in the 75 degree column has an ampacity of 25 amps.
As far as the OCPD this is determined by the Maximum Circuit Breaker or Fuse listing on the unit nameplate. Since this device will only be providing short circuit and ground fault protection it can be sized larger than the ampacities listed in table 310.16. The maximum size will be listed on the unit nameplate.
Article 440 applies to AC units which permit you to use the ampacity listed in table 310.16. In this case your #12 AWG is fine for a nameplate listed minimum circuit ampacity of 21 amps. #12 THHN in the 75 degree column has an ampacity of 25 amps.
As far as the OCPD this is determined by the Maximum Circuit Breaker or Fuse listing on the unit nameplate. Since this device will only be providing short circuit and ground fault protection it can be sized larger than the ampacities listed in table 310.16. The maximum size will be listed on the unit nameplate.
1793
Senior Member
- Location
- Louisville, Kentucky
- Occupation
- Inspector
Re: Outdoor condensing Unit
While we are on the AC topic, can anyone tell me how you determine the "tonnage" of an AC unit? Most nameplates I've seen list the information stated in this thread. I have a one of the Load Calculation programs, and it keep referring to 1.5 ton, 2 ton etc...
As always I look forward to your reply(s)
Norb
While we are on the AC topic, can anyone tell me how you determine the "tonnage" of an AC unit? Most nameplates I've seen list the information stated in this thread. I have a one of the Load Calculation programs, and it keep referring to 1.5 ton, 2 ton etc...
As always I look forward to your reply(s)
Norb
fc
Senior Member
- Location
- New Jersey
Re: Outdoor condensing Unit
If the name plate tells you the btu's a quick way is 12,000 btu's = 1 ton.
Here is a BTU to KW calculator
http://www.ferroli.co.uk/Commercial/BTU_to_kW.htm
[ September 22, 2005, 08:01 PM: Message edited by: fc ]
If the name plate tells you the btu's a quick way is 12,000 btu's = 1 ton.
Here is a BTU to KW calculator
http://www.ferroli.co.uk/Commercial/BTU_to_kW.htm
[ September 22, 2005, 08:01 PM: Message edited by: fc ]
1793
Senior Member
- Location
- Louisville, Kentucky
- Occupation
- Inspector
Re: Outdoor condensing Unit
Thanks to all who have answered the tonnage question. this is the type of information I was looking for.
Norb
Thanks to all who have answered the tonnage question. this is the type of information I was looking for.
Norb
Re: Outdoor condensing Unit
Norb,
Did you know that a ton of AC derives from the amount of heat required to melt a ton of ice in 24 hours.
That is, a ton of AC is equivalent to 12,000 BTU per hour or 288,000 BTU per day.
[ September 24, 2005, 06:07 PM: Message edited by: rattus ]
Norb,
Did you know that a ton of AC derives from the amount of heat required to melt a ton of ice in 24 hours.
That is, a ton of AC is equivalent to 12,000 BTU per hour or 288,000 BTU per day.
[ September 24, 2005, 06:07 PM: Message edited by: rattus ]
electricman2
Senior Member
- Location
- North Carolina
- Occupation
- Retired Electrical Contractor
Re: Outdoor condensing Unit
And after you have applied all that heat you have not changed its temperature. Still 0?C.
And after you have applied all that heat you have not changed its temperature. Still 0?C.
davedottcom
Senior Member
Re: Outdoor condensing Unit
Speaking of Outdoor Condensors... mine just stopped condensing!
Shweaty Dave
Speaking of Outdoor Condensors... mine just stopped condensing!
Shweaty Dave
Re: Outdoor condensing Unit
Dave,
Better determine the problem first.
Does the fan run?
Does the compressor run?
Do you have a leak?
I have changed fan motors, start caps, run caps, contactors, terminal lugs, etc. to keep my 40 year old DayNight running. Just replaced it though because it was too small.
Open it up and see if any electrical parts are smoked. Could be the squirrels have eaten the control wiring. Could be a crimp-on lug has failed. Could be that the contacts are burned. Could be you can fix it yourself.
[ September 25, 2005, 10:04 AM: Message edited by: rattus ]
Dave,
Better determine the problem first.
Does the fan run?
Does the compressor run?
Do you have a leak?
I have changed fan motors, start caps, run caps, contactors, terminal lugs, etc. to keep my 40 year old DayNight running. Just replaced it though because it was too small.
Open it up and see if any electrical parts are smoked. Could be the squirrels have eaten the control wiring. Could be a crimp-on lug has failed. Could be that the contacts are burned. Could be you can fix it yourself.
[ September 25, 2005, 10:04 AM: Message edited by: rattus ]
davedottcom
Senior Member
Re: Outdoor condensing Unit
Rattus, I'm going out to start poking and prodding right now!
So far all I know is the fan runs, not sure about the compressor motor, not sure about a leak.
I'll inspect & clean every connection I can find!
Rattus, I'm going out to start poking and prodding right now!
So far all I know is the fan runs, not sure about the compressor motor, not sure about a leak.
I'll inspect & clean every connection I can find!
- Location
- Massachusetts
Re: Outdoor condensing Unit
Dave there is darn little to look at out there, as Rattus points out hit the basics.
If you have a leak the low pressure cut out should be holding the compressor off line.
Look at the schematic and see if you can locate it. Once you find it see if the switch is open or closed, if it is open that is when I would have to call for some help.
The sealed compressors are pretty reliable.
Dave there is darn little to look at out there, as Rattus points out hit the basics.
If you have a leak the low pressure cut out should be holding the compressor off line.
Look at the schematic and see if you can locate it. Once you find it see if the switch is open or closed, if it is open that is when I would have to call for some help.
The sealed compressors are pretty reliable.
davedottcom
Senior Member
Re: Outdoor condensing Unit
Compressor motor runs.
No sign of any leaks, although I don't really know what it would look like, but nothing obvious!
Here's the weird thing. It's blowing out Hot air. Not just warm air from the ducts in the attic, I mean HOT air as if it heating!
Oh, and there is a little red light thats blinking on the little circuit board!?!?
Editted: Help....I'm Melllllllttting!
[ September 25, 2005, 11:07 AM: Message edited by: davedottcom ]
Compressor motor runs.
No sign of any leaks, although I don't really know what it would look like, but nothing obvious!
Here's the weird thing. It's blowing out Hot air. Not just warm air from the ducts in the attic, I mean HOT air as if it heating!
Oh, and there is a little red light thats blinking on the little circuit board!?!?
Editted: Help....I'm Melllllllttting!
[ September 25, 2005, 11:07 AM: Message edited by: davedottcom ]
jimwalker
Senior Member
- Location
- TAMPA FLORIDA
Re: Outdoor condensing Unit
As an electrician you should be able to locate the problem.About only problem you might run into is if the compressor burned up.At that point it might not be worth it on a 6 year old.Borrow or buy a cheap set of gages.Some will not run if there is no freon in it.Really a very simple piece of equipment when you look at it one piece at a time.Good luck.
As an electrician you should be able to locate the problem.About only problem you might run into is if the compressor burned up.At that point it might not be worth it on a 6 year old.Borrow or buy a cheap set of gages.Some will not run if there is no freon in it.Really a very simple piece of equipment when you look at it one piece at a time.Good luck.
Re: Outdoor condensing Unit
Is this a heat pump as well?
Is the liquid line warm and the suction line cold?
Is the condenser fan running?
Is the fire on in the furnace perhaps?
Is the ductwork OK?
The flashing light will tell the HVAC man what is wrong. Check your user manual, it may tell you what that means.
Be careful if you use gages. Liquid Freon spewing out can give you serious frostbite. Better to call a pro.
[ September 25, 2005, 11:20 AM: Message edited by: rattus ]
Is this a heat pump as well?
Is the liquid line warm and the suction line cold?
Is the condenser fan running?
Is the fire on in the furnace perhaps?
Is the ductwork OK?
The flashing light will tell the HVAC man what is wrong. Check your user manual, it may tell you what that means.
Be careful if you use gages. Liquid Freon spewing out can give you serious frostbite. Better to call a pro.
[ September 25, 2005, 11:20 AM: Message edited by: rattus ]
davedottcom
Senior Member
Re: Outdoor condensing Unit
Most of the lines I touched were Hot!
Fan is running.
No "fire" anywhere!
Duct work is great!
Looking for manual!
Yes it is a Heat pump.
Most of the lines I touched were Hot!
Fan is running.
No "fire" anywhere!
Duct work is great!
Looking for manual!
- Location
- Massachusetts
Re: Outdoor condensing Unit
I would look to see if the reversing valve is either stuck or being 'told' to go to heat mode.
Is the outdoor coil getting cool instead of warm?
Try the manufactures web site you may be able to download the manual and find out the red lights meaning.
I would look to see if the reversing valve is either stuck or being 'told' to go to heat mode.
Is the outdoor coil getting cool instead of warm?
Try the manufactures web site you may be able to download the manual and find out the red lights meaning.
davedottcom
Senior Member
Re: Outdoor condensing Unit
Update! I might have found the problem!
Excuse my lact of proper terminology for these parts but here goes...
At the bottom of the compressor there is some type of connection (2 wires) The connector is round like a capsule and looks sort of like porcelean inside. The connecter is broken off & looks very coroded. The 2-wire looks like a piece of black #14 lamp cord that runs from this connection on the compressor to L1 and also to some other type of sensor that is "snapped" onto one of the copper lines from the condensor.
It's extremely difficult to get to this connection and it doesn't look like it can be replaced without changing the compressor but I'm not sure yet!
No manual to speak of.
I'll try the website.
Update! I might have found the problem!
Excuse my lact of proper terminology for these parts but here goes...
At the bottom of the compressor there is some type of connection (2 wires) The connector is round like a capsule and looks sort of like porcelean inside. The connecter is broken off & looks very coroded. The 2-wire looks like a piece of black #14 lamp cord that runs from this connection on the compressor to L1 and also to some other type of sensor that is "snapped" onto one of the copper lines from the condensor.
It's extremely difficult to get to this connection and it doesn't look like it can be replaced without changing the compressor but I'm not sure yet!
No manual to speak of.
I'll try the website.
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