testing AC float-switch

**John Arnold** · 07-31-2007, 06:49 AM

Is testing the AC pan float-switch as easy as lifting the float and seeing if the equipment immediately shuts down? Or would the equipment keep running for a short time, for some reason?

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David Banks · 07-31-2007, 06:53 AM

Not sure if they shut down immediately but there was a thread a while back that someone said lifting the float may not always work as some are moisture activated and something else I forgot.

**John Arnold** · 07-31-2007, 06:59 AM

Originally Posted by David Banks

Not sure if they shut down immediately but there was a thread a while back that someone said lifting the float may not always work as some are moisture activated and something else I forgot.

Thanks, David. Seems like if it was moisture activated, it wouldn't have float, but what do I know? Maybe they have both? I'll search the forum, as I am constantly suggesting others do.

**Phillip Stojanik** · 07-31-2007, 07:04 AM

A float switch should shut down the A/C condenser unit when its lifted. The interior fan may continue to run continuously or may time out and then shut down depending on where in the control circuit the switch has been wired. The only thing it has to shut down though is the condenser unit.

**John Arnold** · 07-31-2007, 07:05 AM

According to the other thread, some switches are wired to shut down only the condenser, so I may have made a bogus call. Not the first. Or the last.

**Phillip Stojanik** · 07-31-2007, 07:18 AM

Originally Posted by John Arnold

According to the other thread, some switches are wired to shut down only the condenser, so I may have made a bogus call. Not the first. Or the last.

John,

Keep in mind that when the condenser unit shuts down there is still head pressure in the refrigerant circuit. In most cases the "hissing" of refrigerant flow at the evaporator will continue for a minute or so even though the compressor in the outside condenser has shut down.

If you are up in the attic relying on the sound of refrigerant flow to determine if the condenser shut down you might think the compressor is still running when its not.

**Jerry Peck** · 07-31-2007, 01:53 PM

Being as I never figured out how to be in two places remotely located from each other at the same time, I never figured out how to report on those, other than to report when they were improperly installed in some way.

How many worked and how many did not was way beyond what I could do.

I guess I could have stayed around there long enough to feel the refrigerant lines go warm.