Gree GWC09AA, Installation And Service Manual

Page: 94 / 136

GREE Service Manual GWC09AA / K5NNA6A Page 94
Pressure Test (Strength test) with OFDN
After any modification or repair to the AC system “intervention into the refriger-
ant circuit”, at least the affected part (refrigerant circuit piping or piping
connections) shall be subjected to a strength test (pressure test). The strength
test pressure shall not exceed the strength test pressure applied to components
by the manufacturer; this may require the testing of the low-pressure side of the
system separately from the high-pressure side. In fact, this is not possible for
the installed GREE AC units and, in specific for heat-pumps (not applicable
here), is not necessary. The pressure in the system shall be built up gradually
and monitored by remote gauge or other indicator located in a safe place. Use
the Nitrogen cylinders outlet pressure gauge (or an intermediate pressure gauge
between pressure regulator and AC outdoor unit) for pressure monitoring.
Do not use the manifold gauge set for strength test pressure monitoring. This is
a dangerous practice and may cause violation.
Ensure that the pressure regulator at the Nitrogen cylinder is suitable for
the use with RAC systems
(maximum output 50 bar)! Ensure that no un-
authorised persons are within vulnerable locations in case of an inadver-
tent pressure burst.
Interconnection
of the Manifold
Gauge Set should
only be consid-
ered for refriger-
ant handling or
low-pressure
OFDN use.
High pressure
OFDN use will
cause early me-
chanical wear of
the gauge set and
manifolds sup-
plied with sight
glass can cause
violation by acci-
dentally pressing
out the glass
from the body!
Never switch
ON the AC
system if
charged with
OFDN!
The Pressure
Test Value for
the AC system
(Strength Test)
is at 1.1 times
the Maximum
Allowable Pres-
sure (PS), which
is indicated at
the outdoor units
data plate.
Pressure Test
Value = 1.1 x
PS (40 bar) =
44 bar (4.4 MPa)
L
N
Example of an intermediate (Hose N)
installed pressure gauge.