4 | AN233086441027en-000501 - 8510280P01AA
© Danfoss | DCS (CC) | 2021.03
pressure valve, water filter, etc.). If all these
are OK, the problem may be due to either
refrigerant overcharging or the presence of
a noncondensable (e.g. air, moisture) in the
circuit.
•
The low-pressure switch trips out: Check
evaporator operations (coil cleanliness, fan
operations, water flow, water filter, etc.), liquid
refrigerant flow and pressure drops (solenoid
valve, filter dryer, expansion valve, etc.),
refrigerant charge.
• Low refrigerant charge: The correct refrigerant
charge is given by the liquid sight glass
indication, the condenser delta T in relation
to the refrigerant pressure tables (pressure-
temperature), the superheat and the sub-
cooling, etc. (if additional charge is deemed
necessary, refer to section 8).
•
Compressor short cycling: The number of
cycles shall never exceed 12 starts per hour.
12 – Maintenance
Internal pressure and surface temperature
are dangerous and may cause permanent injury.
Maintenance operators and installers require
appropriate skills and tools. Tubing temperature may
exceed 100°C / 212°F and can cause severe burns.
Ensure that periodic service inspections to
ensure system reliability and as required by local
regulations are performed.
To prevent system related compressor problems,
following periodic maintenance is recommended:
• Verify that safety devices are operational and
properly set.
• Ensure that the system is leak tight.
• Check the compressor current draw by reading
one of the parameters via Modbus.
• Confirm that the system is operating in a way
consistent with previous maintenance records
and ambient conditions.
• Check that all electrical connections are still
adequately fastened.
•
Keep the compressor clean and verify
the absence of rust and oxidation on the
compressor shell, tubes and electrical
connections.
•
Acid / moisture content in system and oil
should be checked regularly.
13 - Warranty
Always transmit the model number and serial
number with any claim filed regarding this
product.
Use the fault memory of the frequency converter
to recover the fault descriptions before initializing
the system and even before shutting off the
power.
Variable speed drive model and serial number
must also be transmitted with the claim.
The product warranty may be void in following
cases:
• Absence of nameplate.
• External modifications; in particular, drilling,
welding, broken feet and shock marks.
• Compressor opened or returned unsealed.
• Rust, water or leak detection dye inside the
compressor.
• Use of a refrigerant or lubricant not approved
by Danfoss.
• Any deviation from recommended instructions
pertaining to installation, application or
maintenance.
• Use in mobile applications.
• Use in explosive atmospheric environment.
• No model number or serial number transmitted
with the warranty claim.
14 – Disposal
Danfoss recommends that compressors and
compressor oil should be recycled by a
suitable company at its site.
Danfoss A/S
6430 Nordborg
Denmark
