Charging Procedures
QM 20/QM 30 Ice Machines
The QM 20/QM 30 ice machines are critically charged.
There are no refrigerant access ports on these ice machines.
1.
Locate the high and low side process tubes.
Install a piercing valve (saddle valve) on both the high
and low side process tubes.
IMPORTANT
Remove piercing valves after charging. Unit is critically
charged.
2.
Recovery: Operate the recovery unit as directed by the
manufacturer's instructions.
3.
Replace cap tube assembly and line drier.
IMPORTANT
Purge system with nitrogen while brazing to prevent
build up of copper oxide in the refrigeration system.
4.
Pressure test system with nitrogen to verify no leaks are
present.
5.
Evacuate system to 250 microns. Then allow vacuum
pump to run for an additional 1/2 hour.
REFRIGERANT CHARGE
Important
This unit is critically charged.
Model
Refrigerant Type
Quantity
QM 20
R 134a
130 g (4.59 oz.)
QM 30
R 134a
165 g (5.78 oz.)
6.
Manifold gauges must be removed properly to ensure
that no refrigerant contamination or loss occurs. A
quick disconnect is required for the high side connection
unless high side valve has shut off. Using a digital scale
add the proper refrigerant charge (shown on nameplate)
through the high side.
7.
Let the system “settle” for 2 to 3 minutes.
8.
Place the toggle switch in the ICE position.
9.
Close the high side on the manifold gauge set.
10.
Make sure that all of the vapor in the charging hoses is
drawn into the ice machine before disconnecting the
charging hoses.
A.
Disconnect the water pump.
B.
Run the ice machine in the freeze cycle.
C.
Close the high side piercing valve (if required) and
remove the high side hose with the quick
disconnect.
D.
Open the high and low side valves on the manifold
gauge set. Any refrigerant in the lines will be pulled
into the low side of the system.
E.
Allow the suction pressure to reach 6.89-kPA (0
psi) while the ice machine is in the freeze cycle.
F.
Using a pinch-off tool, pinch off the high and low
side process tubes and remove both piercing valves.
G.
Using an oxygen/acetylene torch seal the
penetrations from the piercing valves.
Refer to QM 20 Installation Use and Care and Service
Manual P/N 80-1057-3 or the QM 30 Installation Use and
Care and Service Manual
P/N 80-1121-3, for complete service diagnostics.
Contact the Service Department if you require further
assistance diagnosing The QM 20/QM 30 ice machines.
They will need the temperatures as listed on the previous
page, to diagnose the problem.
IMPORTANT
Manifold gauges must be removed properly to ensure
that no refrigerant contamination or loss occurs. A
quick disconnect is required for the high side connection
unless high side valve has shut off.
