The following table displays present Danfoss non-return valve selection per each
specific
compressor.
Compressor model
NRV model
VCH115
NRV 19
Assembly line procedure
Reduce moisture in the system
Excessive air and moisture
• can increase condensing pressure and cause high discharge temperatures.
• can create acid giving rise to copper platting.
• can destroy the lubricating properties of the oil.
All these phenomena can reduce service life and cause mechanical and electrical compressor failure.
Requirements
The compressors are delivered with < 100 ppm moisture level. At the time of commissioning, system moisture
content may be up to 100 ppm.
During operation, the
filter
drier must reduce this to a level between 20 and 50 ppm.
Solutions
To achieve this requirement, a properly sized and type of drier is required. Important selection criteria’s include:
• driers water content capacity,
• system refrigeration capacity,
• system refrigerant charge.
For new installations of the compressors with POE oil, Danfoss recommends using the Danfoss DML (100%
molecular sieve) solid core
filter
drier.
Compressor storage
Store the compressor in a manner that it is not corrosive or
flammable
atmosphere between -35°C to 70°C (-31°F to
158°F) when charged with nitrogen and between -35°C (-31°F) and 55°C (131 °F) when charged with R410A
refrigerant.
Compressor holding charge
Each compressor is shipped with a nominal dry nitrogen holding charge between 0.3 and 0.7 bar (4 psi and 10psi)
and is sealed with elastomer plugs.
Respect the following sequence:
• Remove the nitrogen holding charge via the suction Schrader valve to avoid an oil mist blow out.
• Remove the suction plug
first
and the discharge plug afterwards to avoid discharge check valve gets stuck in open
position.
An opened compressor must not be exposed to air for more than 20 minutes to avoid moisture is captured by the
POE oil.
Handling
• Use lifting equipment rated and
certified
for the weight of the compressor or compressor assembly.
• A spreader bar rated for the weight of the compressor is highly recommended to ensure a better load distribution.
• The use of lifting hooks closed with a clasp is recommended.
• Never use the lift rings on the compressor to lift the full unit.
Maintain the compressor in an upright position during all handling manoeuvres (maximum of 15° from vertical).
Scroll compressors, VCH115 | Application
© Danfoss | Climate Solutions | 2023.08
AB392939083370en-000202 | 44