Danfoss VLZ065, Application Manuallines

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Manage oil in the circuit
Test N° Purpose Test condition Pass criteria Solutions
1
Check proper
oil return
Lowest foreseeable evaporation,
and highest foreseeable
condensation.
Minimum speed running 6 hours.
Oil level must be visible or full in the
sight glass when the compressor is
running.
1. Top-up with oil, generally 1-2% of
the total system refrigerant charge
(in weight). Above 3% look for
potential oil trap in the system.
2. Adjust oil boost function, for more
details see section “Oil management
logic”.
A
R
Requirement
System evaluation
Test, criteria and solutions
Oil level must be visible or full in the sight
glass when the compressor is running and when
all compressors of the circuit are stopped.
For VLZ, an oil separator is mandatory to use to
guarantee oil return.
Single compressor
1. Since each installation is unique, test cannot validate the oil return, Oil separator* is mandatory
2. Pay special attention to “Piping design” on field
3. Oil level must be checked and adjusted at commissioning.
*Oil separator
Oil separator which has the internal
reintegration system is recommended, such as
floating ball oil separator.
Oil return injection must be done in suction
line and not in oil sump. If there is a suction
accumulator, place the oil return on suction pipe,
between suction accumulator and compressor
suction port.
In any case, the T° measurement used for
superheat control, (bulb or sensor ) must be
placed before the oil injection.
NRV must be used at outlet of oil separator to
prevent Compressor Off Cycle migration issues.
Do not place the oil separator in the air flow, to
avoid having oil separator acting as a condenser.
Oil separator
Check valve
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AB444226142054en-000101