F3D3
Series
Service Manual Refrigeration / Section 4.4
Questions? Call Franke Technical Support Group For Your Area. Copyright
2012 Franke, Inc. All rights reserved.
4.4 Checking System [Refrigerant] Pressure
and
Electronic Leak Detection…
[F3D3 & F3D3S Models ONLY]
1)
Roll unit out to disconnect power at outlet. [Pull plug.]
2)
Position a stepladder or stable work platform to access
the compressor/condenser compartment from the top.
3)
Using standard manifold refrigeration gauges, securely
attach connectors to discharge & suction access valves.
4)
Plug in unit. Turn ON Main Power Switch and allow
compressor to run for several minutes to stabilize
pressures.
5)
Using gauges, confirm the following pressures for units
with a
16 oz. [454 gm] R404A charge:
Discharge Valve: 230 +/- 10 psig [16
±
1 Bar]
@
80˚F/27
°
C ambient
Suction Valve: 5 +/- 2 psig [.4
±
.1 Bar]
@
80˚F/27
°
C ambient
6)
If Discharge Valve pressure is HIGH and Suction Valve
pressure is LOW, check for a kinked or restricted line.
7)
If a kinked or restricted line is found,
see Section 4.6
for
Expansion Valve/Filter replacement.
8)
If Discharge Valve Pressure is LOW and Suction
Pressure is LOW, verify leak and location with an
Electronic Leak Detector. [If existing system pressures
are high enough, a thorough scan with a standard leak
detector may be sufficient to locate the exact location.]
9)
If system pressure is too low or leak(s) is/are intermittent
and difficult to detect, recover any remaining refrigerant
then pressurize the system with nitrogen to an equalized
MAXIMUM of 150 PSIG [10.5 Bar];
per Section 4.4A
10)
NOTE:
If using an electronic leak detector, add a few
ounces of R-404A to act as a tracer gas. Use electronic
leak detector or apply soap solution to locate any leaks.
11)
IMPORTANT
: Make sure the condensing unit is off when
checking for leaks. Air movement from the fan would
inhibit the ability of the leak detector to sense refrigerant.
12) If a leak is found, see Section 4.5 for Leak Repair
Procedures.
[Photo 1] F3D3S from back
Access the refrigeration
compartment from back or top.
[Photo 2]
Check Discharge and Suction
Valve pressures using a
manifold refrigeration gauge.
[Photo 3]
If system pressure is too low or
the leaks difficult to pinpoint,
pressurize system with 150
PSIG [10.5 Bar] of Nitrogen and
use an electronic leak detector
or soap solution.
Rev. 1 6/2012
Tools Required:
Medium Phillips Screwdriver
Manifold Refrigeration
Pressure Gauge
Electronic Refrigeration Leak
Detector or
Liquid leak-detection soap
NOTE
: Do not use an electronic leak detector to locate
leaks inside the freezer evaporator housing. The foam
insulation used inside the evaporator housing contains
HFCs, which will generate false readings.
See Section
4.4B for Nitrogen Pressure Testing of Evaporator.
