Why is this AC unit working?

[Dan Harris]

This AM inspection on a 1 yr old home.
One of the wires for an AC unit was never connected to the breaker. The unit was working fine.

[Rod Butler]

This AM inspection on a 1 yr old home.
One of the wires for an AC unit was never connected to the breaker. The unit was working fine.


Ground?

[Jim Luttrall]

This AM inspection on a 1 yr old home.
One of the wires for an AC unit was never connected to the breaker. The unit was working fine.

You are going to need to be a bit more specific and maybe have some photos.
But you may have a 4 wire feed to a straight 240 volt system which does not require a neutral.

[Dan Harris]

You are going to need to be a bit more specific and maybe have some photos.
But you may have a 4 wire feed to a straight 240 volt system which does not require a neutral.


I gave up on trying to figure out how to post photos :)
It was a typical 240 set up. One of the wires going to the top side of the 30 Amp breaker was there and bent to go in the breaker, but it was never installed on the breaker, the screw on the breaker was missing.

There were 2 units the other unit was properly wired.

[David Bell]

Some smaller ductless splits are 115 volt, Outdoor unit? tonnage?

[Dan Harris]

Some smaller ductless splits are 115 volt, Outdoor unit? tonnage?

It was a 3 Ton unit outside with the air handler in the attic.
Per Mfg.label Max 30 amp bkr.

[James Duffin]

Did you cut off the breaker in question to see if the unit actually went off? Maybe it is labeled wrong and is fed from another breaker?

[Dan Harris]

Did you cut off the breaker in question to see if the unit actually went off? Maybe it is labeled wrong and is fed from another breaker?

I did and it shut it off.

[David Bell]

Did the air handler shut off too? If so it may be just cutting low voltage to the contactor.

[Jim Luttrall]

Did the air handler shut off too? If so it may be just cutting low voltage to the contactor.

Agreed, one thing for sure, if there was no second leg to a 240 volt circuit, then there won't be any 240 volt appliances running (at least not for long.)

[Wayne Carlisle]

Maybe the fan on the outside unit was working but not the compressor. The fans are 110/120 volt.

[David Bell]

Maybe the fan on the outside unit was working but not the compressor. The fans are 110/120 volt.
Not on most everything I see, they are psc motors and usually part of a dual cap system. And on the higher seer units they are variable speed

[Wayne Carlisle]

I just read the question and didn't really notice when the house was built....the new houses we see are thgis way also...older houses..different scenario

[H.G. Watson, Sr.]

I just read the question and didn't really notice when the house was built....the new houses we see are thgis way also...older houses..different scenario


This AM inspection on a 1 yr old home.
One of the wires for an AC unit was never connected to the breaker. The unit was working fine.


Hard to miss 1 yr old home. ;)

I question the assertion that the wiring wasn't complete.

Suspect in-line or tapped device, such as a remote poco controlled demand switch (often referred to as a direct load control switch) allowing the poco to cycle down/interrupt for brief time periods of high system demand, but still allowing circulation fans to operate. Different POCOs have differing programs, not always involving seperate meters for various energy programs. Usually same interupts only the compressor, not the circulation fans (nor heats if present). More often than not the load control receiver taps into the 240 circuit for its power source and interupts the 24v thermostat control circuit by opening a normally closed position relay for scheduled time periods (such as x minutes per hour interuption during certain hours on weekdays on high system demand days). Some POCOs have similar remote signal or radio signal direct load control programs for electric storage type water heaters, electric heat, and pool equipment. Other programs may involve separate metering control devices.

Since no assertion or evidence the breaker did not have two hots, I doubt the wiring path was fully traced. I further suspect a heat pump (packaged or split), and not AC.

Posting photos is an easy enough thing to accomplish. Next time you are in the process of posting, use your overall screen scroll bar or page down button to look at the screen below the post composition "box" (not the scroll bar within the composition box to the left of the "smiley" icons).

To attach a file (or up to... I believe five is the limit per post) to a post, one merely has to first size those files to be within the limits allowed on the forum, and re-format them to a file type and/or size suitable for posting. You can use the "attach photos" area which appears in a "box" below the banner ad under the "post composition box" that you type in to create or edit your posts. It appears BELOW the "submit reply/preview post" buttons, and BELOW the banner ad. You can upload your properly sized (800x600 or less) overall file sizes and types display when you click on the "upload photos" button. You have to have your browser set to allow new windows to pop-up, and allow scripts to load to see this pop-up window).

This box will allow you to navigate your hard drive or remote drive to find and identify the photo/files you wish to upload. Once you have identified all that you wish to attach, don't forget to click on the UPLOAD files button just below the file name list, and wait for the system to notify you that uploading is complete message in the center of that same pop-up window. When uploading is complete, close that pop-up window, resume your post composition, then complete your post in the usual way.

Should that prove too challenging, you can use the icon above the composition box, second in from the right (looks like a yellow post-card with a stamp on the upper right) and in the diaglog box which appears enter the web address of the photo hosted elsewhere on the web and insert a full-size (but appropriately sized) image of your photo(s) into the text display of your post.

Even freebie programs such as "paint", etc. can accomplish this "resizing" easily (both pixel and overall file size, and to change file format type if necessary). If you find that too challenging, you can upload your photos onto a free photo hosting site, set your permissions for the album you create to public, and include LINKS to those photos within your post/text.

[David Bell]

Mis-tagged is obvious, that the unit shuts down proves it controls the low voltage,IE transformer. Outdoor unit may have a fused disconnect wired from a seperate source supplying all the condensing units.

[Rolland Pruner]

Sounds like not grounded, what color was wire? Pictures?