FloAire Direct Expansion Coil Modules - Manual (Page 9)

9
C H A R G IN G S Y S T E M
S U C T IO N L IN E
G A U G E
C O M P R E S S O R
S C A L E
T o T a n k (Y e llo w )
R E F R IG E R A N T
3. Vacuum the lines
A. Find and install the valve cores located on your compressor unit. If you cannot find the
taps, check the owner’s manual.
B. Install the pressure gauge manifold. Make sure both valves are closed on the manifold.
The blue line goes to the suction line and micron gauge. The yellow line connects to a
vacuum pump. Start the vacuum pump. To start vacuuming the system, open the blue
line side of the manifold. You should see the pressure start to drop.
C. Continue to vacuum the lines for 15 minutes, and then stop. If the vacuum on the lines
doesn’t hold, you have a leak. Repeat step 2 to fix the problem. If it holds, read the
micron gauge. If the gauge does not read below 500, continue to vacuum the lines until
the gauge does. You are now removing the moisture from the lines. This is very
important!!! The more moisture you remove now, the more efficiently your system will
run. Close the valves to the pump and the system should be able to maintain a 1000
micron vacuum continuously.
4. Installing the refrigerant. You will need a tank of
refrigerant and a scale. The scale must be able to
read ounces and have a max capacity of 50 Lbs.
The refrigerant will come from a HVAC professional.
Make sure to read the condenser owners manual
for what kind of refrigerant and how much you will
need for your system. This step will be done while
the condenser is off.
A. Attach the red line to the liquid line
B. Open the valves on the unit. This will
release the holding charge into the circuit.
C. Attach the yellow hose to the tank of
refrigerant, open the valve on the tank, and
invert the cylinder on the scale.
D. Open the blue valve on the manifold,
slightly. This will allow charge to enter into
the circuit.
E. Close the valve on the manifold after 80% (by weight) of the charge has been introduced.
F. RECORD THE WEIGHT OF THE TANK. This will tell you how much charge is left in the
tank.
5. Trimming the refrigerant charge. Once the initial charge has been introduced into the system,
allow the compressor to run for 15 minutes. This will balance the charge and help ensure
accurate readings.
A. Locate the charging chart in the compressor owner’s manual. Each chart will be different
depending on the manufacturer of condenser unit. Most require a liquid pressure and
temperature to be known.
B. Record the liquid line temperature and pressure. With the charging chart, plot the point
where the system is operating. Note if it falls into the Add Charge or Reduce Charge.
I. Add charge. Slowly turn the Blue side of the pressure gauge manifold. This will
allow the charge from the tank to enter the suction side of the compressor. After
a sufficient amount of refrigerant has been added, close the blue side valve and
allow the system to stabilize. Recheck temperature and pressure; re-plot the
point on the chart, and repeat the process if necessary.
II. Reduce charge. In the case of overfilling the circuitry, the excess refrigerant
must be recovered into an approved cylinder. Seek professional help for this
step.
C. Weight the tank and record the changes.