Outdoor Unit Blowing Warm Air

[HvaC newbee]

I am an Electrician who has recently gained the F Gas qualification. At work last night I discovered an AC unit running incorrectly. The indoor unit was blowing, but the outdoor was blowing cold air.! I had no tools to investigate, but my initial feeling is the unit has a leak and/or age has caused the unit to be low on refrigerant .
Would this be a reasonable diagnosis? ( the unit was set to cool @ 19 degrees)

Thank you

[install monkey]

thought all sparks had a neon driver and a volt stick:Dquick pointers- was the room above 21deg? was the compressor running, check the control circuit- look for pressure switches open circuit,is power correct to the unit,is there a reversing valve? is the compressor pumping? problem is now u got ur f gas ticket- ur boss will think he can send you to any ac unit- problem being is a 5 day course will not give you the knowledge,experience familiarisation of different systems-

[HvaC newbee]

The room was 30 degrees, the compressor kicked in for a matter of seconds, cyclically, and there is a reversing valve, albeit the system has always been set to cool, and referencing the maintenance logs, was operating correctly 2 month ago. Between then and now, the valve would not need to operate anyway due to the excessive ambient temperature(?).

We're a big company, and ourselves, and boss included, are aware of our limits. If we struggle, we have the facility to bring in an external contractor ( or expert, as I like to call them, who has done more than a 10 day course, probably an actual apprenticeship!):)

[install monkey]

check compressor current , make sure it aint going out on internal klixon /overload, as before,check pressure switches for open circuit- may be auto reset,good luck

[goshen]

HI
check settings on internal remote or thermostat , make sure it is set for cooling and not heating or auto mode !
good luck

[HvaC newbee]

HI
check settings on internal remote or thermostat , make sure it is set for cooling and not heating or auto mode !
good luck

Hi, it was set to cooling. The units are always set to 19 degrees as the rooms cooled contains safety critical equipment.

The internal unit seemed to be circulating room temperature air. The outdoor unit cooler than ambient temp. air.

My initial thoughts were if the system is running below operating pressure due to low refrigerant levels, this would cause the condensor to blow cold, as the Gas would not have the quantity to sub cool(?).

To reiterate, at the time I had no gauges to confirm this, as I was on an Electrical job within the vicinity

[jdunc2301]

check compressor current , make sure it aint going out on internal klixon /overload, as before,check pressure switches for open circuit- may be auto reset,good luck

God has spoken ;)

[install monkey]

bless you child!:D
keep praying for ur birds boob job!:confused:

God has spoken ;)

[The Viking]

I am an Electrician who has recently gained the F Gas qualification.

my initial feeling is the unit has a leak and/or age has caused the unit to be low on refrigerant .
Would this be a reasonable diagnosis?
:rolleyes:

To answer your question,
NO, sorry.

It Might be short of gas due to a leak,
Other alternative faults has been mentioned above.

However, since you mentioned that it's setpoint is 19 degrees and the indoor unit is in a mission critical room I assume that the unit is serving a server room or similar.
You haven't told us what make and model of unit you are looking at but a real killer for units in equipment rooms is lack of humidity. When the room humidity drop below about 35% most units will go in to frost protection mode and turn themselves ON/OFF on the frost protection circuit instead of the thermostat, other units will lack this function and turn the evaporator in to a block of ice causing the suction pressure to drop like if the system is SOG...

Happy hunting!

:cool: