Instructions
6 | AN24598649703302en-000501 - 8510197P05F
© Danfoss | DCS (CC) | 2019.01
12 – Verification before commissioning
Use safety devices such as safety pressure
switch and mechanical relief valve in compliance
with both generally and locally applicable regu-
lations and safety standards. Ensure that they are
operational and properly set.
Check that the settings of high-pressure swit-
ches and relief valves don’t exceed the maximum
service pressure of any system component.
• A low-pressure switch is recommended to
avoid vacuum operation. Minimum setting for
SM/SY/SZ: 0.5 bar g. Minimum setting for DSH
/ SH / WSH: 1.7 bar g.
• Verify that all electrical connections are pro-
perly fastened and in compliance with local
regulations.
• When a crankcase heater is required, it must be
energized at least 12 hours before initial start-
up and start-up after prolonged shutdown for
belt type crankcase heaters (6 hours for sur-
face sump heaters).
13 – Start-up
Never operate the compressor without the
electrical box cover fitted.
• Never start the compressor when no refrige-
rant is charged.
• All service valves must be in the open position.
• Balance the HP/LP pressure.
• Energize the compressor. It must start promp-
tly. If the compressor does not start, check wi-
ring conformity and voltage on terminals.
• Eventual reverse rotation can be detected
by following phenomena; the compressor
doesn’t build up pressure, it has abnormally
high sound level and abnormally low power
consumption. In such case, shut down the
compressor immediately and connect the
phases to their proper terminals. Most Danfoss
scroll compressors are protected against re-
verse rotation either by an internal reverse ro-
tation protection or by the external electronic
protection module. They will shut off automa-
tically. Only SM 112, 124, 147, SZ147 have no
reverse rotation protection. Prolonged reverse
rotation will damage these compressors.
• If the internal overload protector trips out (SM/
SZ 084, 090, 100, 110, 112, 120, 124, 147, 148,
161 and DSH / SH / WSH 090, 105, 120, 140,
161, 184), it must cool down to 60°C to reset.
Depending on ambient temperature, this may
take up to several hours.
• If the internal pressure relief valve is opened
(SY/SZ 240, 300, 380 / SH 380, 485 / DSH 381,
485, DSH600), the compressor sump will be
warm and the compressor will trip out on the
motor protector.
14 – Check with running compressor
• Check current draw and voltage.
• Check suction superheat to reduce risk of slug-
ging.
• Observe the oil level in the sight glass for
about 60 minutes to ensure proper oil return
to the compressor.
• Respect the operating limits.
• Check all tubes for abnormal vibration. Move-
ments in excess of 1.5 mm require corrective
measures such as tube brackets.
• When needed, additional refrigerant in liquid
phase may be added in the low-pressure side
as far as possible from the compressor. The
compressor must be operating during this
process.
• Do not overcharge the system.
• Never release refrigerant to atmosphere.
• For reversible systems, ensure that the 4-way
valve does not reverse when the compressor
is stopped due to heating or cooling demand
(stop on thermostat)
• Before leaving the installation site, carry out
a general installation inspection regarding
cleanliness, noise and leak detection.
• Record type and amount of refrigerant charge
as well as operating conditions as a reference
for future inspections.
15 – Maintenance
Internal pressure and surface temperature
are dangerous and may cause permanent inju-
ry.Maintenance operators and installers require
appropriate skills and tools. Tubing temperature
may exceed 100°C 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 pro-
blems, following periodic maintenance is recom-
mended:
• Verify that safety devices are operational and
properly set.
• Ensure that the system is leak tight.
• Check the compressor current draw.
• 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 ab-
sence of rust and oxidation on the compressor
shell, tubes and electrical connections.
16 - Warranty
Always transmit the model number and serial nu-
mber with any claim filed regarding this product.
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 instruc-
tions pertaining to installation, application or
maintenance.
• Use in mobile applications.
• Use in explosive atmospheric environment.
• No model number or serial number trans-
mitted with the warranty claim.
The compressor is not designed to withstand
natural disasters such as earthquakes, cyclones,
floods…. or extreme events such as fires, terrorist
attacks, military bombardments, or explosions of
any kind.
Danfoss Commercial Compressor is not liable
for any malfunction of its product resulting from
such events
17 – Disposal
Danfoss recommends that compressors
and compressor oil should be recycled
by a suitable company at its site.
Danfoss can accept no responsibility for possible errors in catalogues, brochures and other printed material. Danfoss reserves the right to alter its products without notice. This
also applies to products already on order provided that such alterations can be made without subsequential changes being necessary in specifications already agreed. All trade-
marks in this material are property of the respective companies. Danfoss and the Danfoss logotype are trademarks of Danfoss A/S. All rights reserved.
