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Arnie Goetchius[_2_]

wrote:
On Mon, 24 Aug 2015 17:08:41 -0400, Arnie Goetchius
wrote:

I have a new 4 ton A/C and gas furnace installed in Jan 2015 by a contractor.
This replaced a Colman 4 ton that I installed myself about 25 years ago. The new
A/C Condensing Unit is a Trane 4 ton 4TTR3018-60. The A/C has been running all
summer with out a problem.

Today, after being off for a couple of hours, it started up and the following
happened:

(1) the house lights blinked for about 1/4 to 1/2 second.

(2) the condensing unit ran twice as loud with more vibration as it normally
does for about a couple of minutes and then it resumed its normal
noise/vibration level.

(3) During the time it was running, there was absolutely no cooling. The
temperature at the bonnet was the same as the temperature at the return air duct.

I shut the A/C down by adjusting the thermostat up and called the service tech
who is coming tomorrow morning. After waiting an hour, I dropped the thermostat
and it started right up with no lights blinking. The bonnet is running about
14-16 degrees cooler than the return duct which is normal.

When I read the specs for the compressor, it says the following:

"The Climatuff® compressor features internal over temperature and pressure
protector, total dipped hermetic motor and thermostatically controlled sump
heater. Other features include: roto lock suction and discharge refrigeration
connections, centrifugal oil pump, and low vibration and noise."

Question: Is it possible that the compressor detected a problem and just shut
down but the Condensing Unit fan would still keep running? Also would a 1/4 to
1/2 second blinking of the lights be symptomatic of the problem?

Does it have a restart lockout timer to prevent the compressor from
short cycling? If not, it may have been liquid slugged and overheated.
Letting it settle for a while got it working again and I hope you
didn't really hurt anything.

The thermostat has a lockout timer so you can't turn it on and then off and then
right back on. I think the timer prevents a restart from happening for 3-5 minutes.