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john collier
06-05-2008, 01:02 AM
You are called out for a service call to a reverse cycle split Air Conditioning unit (non inverter model) using R22. On arrival the office manager informs you that there is no cooling from the unti. On inspection the indoor air handler fan lacks sufficient airflow. There is only one access port on the system, on the outside condenser, on the suction line. On fitting your manifold gauges you read the back pressure of 360KPa on your gauge

a. What would be your diagnosis?

b. What would you initially do?

c. What two things would you do to rectify the fault?

taz24
06-05-2008, 01:06 AM
You are called out for a service call to a reverse cycle split Air Conditioning unit (non inverter model) using R22. On arrival the office manager informs you that there is no cooling from the unti. On inspection the indoor air handler fan lacks sufficient airflow. There is only one access port on the system, on the outside condenser, on the suction line. On fitting your manifold gauges you read the back pressure of 360KPa on your gauge

a. What would be your diagnosis?

b. What would you initially do?

c. What two things would you do to rectify the fault?


I do not know what 360KPa is, in English money:)
But I assume it is low.

So no air flow and low suction = blocked evap filter, iced up evap.

taz.

nike123
06-05-2008, 08:09 AM
a. What would be your diagnosis?

b. What would you initially do?

c. What two things would you do to rectify the fault?

a. Dirty indoor unit
b. Cleaning of indoor unit( filter, fan, exchanger)
c. Cleaning of indoor unit and checking of actual capacity after that (anemometer, thermometer, higrometer). Then, act accordingly.

ALONEI
10-05-2008, 04:09 PM
360kpa thats around 52 psi and its not that bad.
its important to know what is the outside temp to determine the posibility of short on refrigerant and also to check the status of the indoor unit as mention before.
after making sure that the indoor coil is clean and there is a good air flow check the press' again and even make a super heat check.
There is also the chance of faulty compressor(normal suction+low discharge)
Good luck

praveen
11-05-2008, 11:17 AM
For me its seem to be either evaporator blower or low pressure.Check the evaporator blower current rating & measure it accordingly.Check for coil area blockage.

Do this pressure fluctuate like sometime increases or some time decreases.

If yes check for capillary operation.

Right now blower or dirty choke evaporator coil is the problem.

praveen
11-05-2008, 11:19 AM
also if discharge pressure is low check for low ambient condition or condenser design for high load