A
PPLICATION
GUIDELINES
23
FRCC.PC.017.A1.02
I
NSTALLATION
Refrigerant charging
Compressor replacement
after motor burn out
It is recommended that system charging be done
using the weighed charge method, adding refrig-
erant to the high side of the system. Charging the
high and low sides of a system with gas simulta-
neously at a controlled rate is also an acceptable
method. Do not exceed the recommended unit
charge, and never charge liquid to the low side.
If there has been a motor burnout follow the
evacuation procedure described on previous
page. Remove and replace the liquid line fi lter
drier and install a Danfoss type DAS burnout drier
of appropriate capacity.
Refer to the DAS drier instructions and technical
information on correct use and monitoring of the
burnout drier and the liquid line and suction line
fi lter driers.
Liquid line fi lter driers
A properly sized fi lter drier is required for all
Danfoss scroll applications. Danfoss recommends
DML (100% molecular seives) driers for HFC refrig-
erants R407C with PVE oil. For servicing of exist-
ing installations where acid formation is present
the Danfoss DCL solid core fi lter driers containing
activated alumina are recommended. The drier is
to be oversized rather than under sized. When se-
lecting a drier, always take into account its capac-
ity (water content capacity), the system refrigera-
tion capacity and the system refrigerant charge.
Insulation resistance and
dielectric strength
Insulation resistance must be greater than 1 meg-
ohm when measured with a 500 volt direct cur-
rent megohm tester.
Each compressor motor is tested at the factory
with a high potential voltage (hi-pot) that exceeds
the UL requirement both in potential and in dura-
tion. Leakage current is less than 0.5 mA.
Performer® Heat Pump scroll compressors are
confi gured with the pump assembly at the top
of the shell, and the motor below. As a result, the
motor can be partially immersed in refrigerant
and oil. The presence of refrigerant around the
motor windings will result in lower resistance val-
ues to ground and higher leakage current read-
ings. Such readings do not indicate a faulty com-
pressor, and should not be cause for concern.
In testing insulation resistance, Danfoss recom-
mends that the system be fi rst operated briefl y
to distribute refrigerant throughout the system.
Following this brief operation, retest the compres-
sor for insulation resistance or current leakage.
