In a Danfoss SH scroll compressor, the
compression is performed by two scroll elements
located in the upper part of the compressor.
Suction gas enters the compressor at the suction
connection. As all of the gas ows around and
through the electrical motor, thus ensuring
complete motor cooling in all applications, oil
droplets separate and fall into the oil sump.
After exiting the electrical motor, the gas enters
the scroll elements where compression takes
place. Ultimately, the discharge gas leaves the
compressor at the discharge connection.
The gure below illustrates the entire
compression process. The centre of the orbiting
scroll (in grey) traces a circular path around
the centre of the xed scroll (in black). This
movement creates symmetrical compression
pockets between the two scroll elements.
Low-pressure suction gas is trapped within
each crescent-shaped pocket as it gets formed;
continuous motion of the orbiting scroll serves
to seal the pocket, which decreases in volume
as the pocket moves towards the centre of the
scroll set increasing the gas pressure. Maximum
compression is achieved once a pocket reaches
the centre where the discharge port is located;
this stage occurs after three complete orbits.
Compression is a continuous process: the
scroll movement is suction, compression and
discharge all at the same time.
SUCTION
COMPRESSION
DISCHARGE
4
FRCC.PC .007.B8.02
Application guidelines
Features
SH range is composed of SH090-105-120140-161-184 (light commercial platform) and
SH180-240-295-300-380-485 (large commercial
platform).
The SH090-105-120-140-161-184 compressors
bene t from a further improved design to
achieve the highest e ciency.
• Gas circulation, motor cooling and oil
behaviour are improved on light commercial
platform models by a new patented motor cap
design.
• Part protection and assembly reduces internal
leaks and increases life durability.
Heat shield that lowers the heat
transfer between discharge and
suction gas and the acoustic level
• Improved part isolation reduces greatly
acoustic levels.
• Gas intake design induces higher resistance to
liquid slugging.
The SH485 compressors include additional
features for enhanced protection and e ciency:
• integrated discharge gas temperature
protection,
• intermediate discharge valves for higher
seasonal e ciency.
• patented gas path ow.
Integrated discharge gas
temperature protection (SH485)
New PTFE spring seal for even
lower leaks
Intermediate discharge valves
(SH485)
R410A optimized and dedicated
scroll pro le
Patented motor cap
Liquid slug protection per suction
tting in upper position
Danfoss SH scroll compressors for R410A are
available as single compressors. The example
below presents the compressor nomenclature
which equals the technical reference as shown on
the compressor nameplate.
Displacement at nominal speed: 2900 rpm at 50 Hz, 3500 rpm at 60 Hz
Net weight with oil charge
TR: Ton of Refrigeration, Standard rating conditions: ARI standard Evaporating temperature: 7.2 °C Superheat: 11.1 K
EER: Energy E ciency Ratio Refrigerant: R410A Condensing temperature: 54.4 °C Subcooling: 8.3 K
COP: Co e cient Of Performance,
Subject to modi cation without prior noti cation.
For full data details and capacity tables refer to Online Datasheet Generator: ww w.danfoss.com/odsg
with a sight glass (1"1/8 - 18 UNF) which may be
used to determine the amount and condition of
the oil contained within the sump.
Oil equalisation connection
SH090-105-120-140-161-184: 1"3/4 rotolock
connector allowing use of 1”3/4 - 7/8" or 1”3/4 1”1/8 sleeve.
SH180-240-295-300-380-485: 2”1/4 rotolock
connector allowing the use of 2”1/4 - 1”3
/8 or
2”1/4 - 1”5/8 sleeve.
This connection must be used to mount an oil
equalisation line when two or more compressors
are mounted in parallel (please refer to Danfoss
SH Parallel Application Guide l ines FRCC.
EC.008.
fordetails).
Oil drain connection
The oil drain connection allows oil to be
removed from the sump for changing, testing,
etc. The tting contains an extension tube into
the oil sump to more e ectively remove the
oil. The connection is a
female 1/4" are tting
incorporating a schrader valve and is mounted on
SH180 - 240 - 295 - 300 - 380 - 485 models only.
Oil ll
connection
and gauge
port
Oil drain
connection
Schrader
Theoil ll connection and gauge port is a 1/4"
le areconnectorincorporatingaschrader
ma
valve.
FRCC.PC.007.B8.02
13
Application guidelines
Electrical data, connections and wiring
Motor voltage
Wiring connections
SH090-105-120-140-161
ExceptSH140-161 code3
DanfossSH scroll compressorsareavailablein ve di erentmotor voltagesas listedbelow.
Motor voltage codeCode 3Code 4Code 6Code 7Code 9
Nominal voltage-
50 Hz
Voltage range-
Nominal voltage200-230V - 3 ph460
60 Hz
Voltagerange180-253 V414-506 V-517-632 V342-418 V
*SH295& 485
Electrical power is connected to the compressor
terminals by Ø 4.8 mm (3/16”) screws.
Theterminal boxisprovidedwithaØ25.5mm
380-400V - 3 ph
380-415V - 3 ph *
340-440 V
340-457V *
V - 3 ph-575 V-3 ph380V- 3 ph
230V - 3 ph500V - 3 ph-
207-253 V450 - 550 V-
The maximum tightening torque is 3 Nm. Use a
ring terminal on the power leads.
1/4’’
Terminal box
(ISO25)andaØ29mm (PG21) knockouts.
Ø 25.5 mm knockout
Ø 29 mm knockout
SH140&161 code 3 & SH184
SH180
The terminal box is provided with a
Ø40.5 mm hole (ISO40) for power supply and
a
Ø16.5 mm knockout (ISO16).
The terminal box is provided with 2 triple
knockouts and 1 single knockout for power
supply and 4 double knockouts for the safety
control circuit.
The motor protection module comes preinstalled within the terminal box and has
pre-wired thermistor connections. The module
must be connected to a power supply of the
appropriate voltage. The module terminals are
6.3mmsize.
Theterminal boxis
providedwith2triple
knockouts and 1 single knockout for power
supply and 4 double knockouts for the safety
control circuit.
within the terminal box. Phase sequence
protection connections and thermistor
connections are pre-wired. The module must be
connected to a power supply of the appropriate
vo
ltage. Themoduleterminalsare 6.3-mmsize
Fastontype.
L1 L2 L3
Black Blue Brown
L N S1 S2 M1 M2
Modulepower
Internal control contac t
Safety
Thermistor
connection
circuit
The compressor terminal box according to IEC529 is IP54 for all models when correctly sized IP54 rated
cable glands are used.
First numeral, level of protection against contact and foreign objects
5 - Dust protected
Second numeral, level of protection against water
4 - Protection
Thetemperatureinsidetheterminal boxmay not
exceed 70°C. Consequently, if the compressor is
installed in an enclosure, precautions must be
taken to avoid that the
compressor and in the terminal box would rise
too much. The installation of ventilation on the
againstwatersplashing
temperaturearoundthe
electronic protection module may not operate
properly. Any compressor damage rel
ated to this
will not be covered by Danfoss warranty. In the
same manner, cables must be selected in a way
to insure that terminal box temperature does not
exceed 70°C.
maximum at which the compressor can be
operated in transient conditions and out of
FRCC.PC.007.B8.02
the starting current. However in most cases, the
real starting current will be lower. A soft starter
can be applied to reduce starting current.
the application envelope. Abo
ve this value, the
internal motor protection or external electronic
module will cut-out the compressor to protect
the motor.
Application guidelines
Electrical data, connections and wiring
Max. operating Current
Winding resistance
Danfoss MCI
soft-start controller
The max. operating current is the current when
the compressor operates at maximum load
conditions and 10% below nominal voltage
(+15°C evaporating temperature and +68°C
condensing temperature).
Winding resistance is the resistance between
phases at 25°C (resistance value +/- 7%).
Winding resistance is generally low and it
requires adapted tools for precise measurement.
Use a digital ohm-meter, a "4 wires" method and
measure under stabilised ambient temperature.
Winding resistance v
aries strongly with winding
temperature; if the compressor is stabilised
at a di erent value than 25°C, the measured
resistance must be corrected with following
formula:
Theinrushcurrent forthe DanfossSH scroll
compressors with motor code 4 (400V /3ph /
50Hz or 460
V / 3ph / 60Hz) can be reduced using
the Danfoss digitally-controlled MCI compressor
soft starter. MCI soft starters are designed
to reduce the starting current of 3-phase AC
motors; they can reduce the inrush current by
upto 40
%, thereby eliminatingthedetrimental
Max Oper. A can be used
toselectcablesand
contactors.
In normal operation, the compressor current
consumption is always less than the Max Oper. A.
value.
a + t
R
= R
tamb
25°C
a + t
t
: reference temperature = 25°C
25°C
t
: temperature during measurement (°C)
amb
R
: winding resistance at 25°C
25°C
R
: winding resistance at tamb
amb
amb
_______
25°C
Coe cienta = 234.5
e ects of high starting torque surges and costly
demand charges from the resultant current
spike. Upon starting, the controller gradually
increases the voltage supplied to the motor until
full-line voltage has been reached.
All settings,
such as ramp-up time (less than 0.5 sec) and
initial torque, are preset and do not require
modi cation.
Input controlled soft start
Compressor model
SH090MCI15CMCI15C
SH105MCI25CMCI25C
SH120MCI25CMCI25C
SH140MCI25CMCI25C *
SH161MCI25CMCI25C *
SH184MCI25CMCI25C *
S
H180MCI50CMMCI50CM
SH240MCI50CMMCI50CM *
SH295MCI50CM *MCI50CM *
SH300MCI50CM *MCI50CM *
SH380MCI50CM *MCI50CM *
SH485NANA
* by-pass contactor K1 is required
Soft start reference
Ambient max. 40°C
When the control voltage is applied to A1 - A2,
the MCI soft starter will start the motor, according
to the settings of the ramp-up time and initial
torque adjustments. When the control voltage
is switched OFF, the motor will switch o
instantaneous
ly.
Soft start reference
Ambient max. 55°C
FRCC.PC.007.B8.02
17
Application guidelines
Electrical data, connections and wiring
MCI with by-pass contactor
General wiring
information
By means of the built-in auxiliary contact (23-24)
the by-pass function is easily achieved, see wiring
diagram beside.
No heat is generated from the MCI. As the
contactor always switches in no-load condition
it can be selected on
the basis of the thermal
current (AC-1).
13-14 contactnotapplicablewithMCI 25C.
Thewiringdiagramsbelowareexamples fora
safe and reliable compressor wiring. In case an
alternative wiring logic is chosen, it is imperative
to respect the following rules:
When a safety switch trips, the compressor must
stop
immediately and must not re-start until
the tripping condition is back to normal and
the safety switch is closed again. This applies to
the LP safety switch, the HP safety switch, the
discharge gas thermostat and the motor safety
thermostat.
Inspeci csit
uations, suchaswinterstart
operation, an eventual LP control for pumpdown cycles may be temporarily bypassed to
allow the system to build pressure. But it remains
mandatory for compressor protection to apply an
LP safety switch. The
LP safety switchmustnever
bebypassed.
Pressuresettings forthe LP and HP safety switch
and pump-down listed in table from section "Low
pressure".
When ever possible (ie. PLC control), it is
recommended to limit the possibilities of
compressor auto restart to less than 3 to 5 times
during a period of 12 hours when caused by
motor protection or LP safety switch tripping.
This control must be managed as a manual reset
device.
Suggested wiring diagrams logic
Compressor model SH 090 - 105 - 120 - 140 - 161 - 184
Compressor modelOverheating protection Over current protection Locked rotor protectionPhase reversal protection
SH 090 - 105 - 120 - 140- 161
SH240 - 295 - 300 - 380-485Electronic module located in terminal box
- 184
SH 180 Electronic module located in terminal boxReverse vent valve
Internal motor protectionPhase sequence detector recommended
Compressor models SH090-105-120-140-161-184
have been provided with an internal overload
motor protection to prevent against excessive
current and temperature caused by overloading,
low refrigerant ow or phase loss. The cutout
current is the MCC value listed in section "Three
phase electrical characteristics".
The protector is located in the star point of the
motor and, should it be activated, will cut out all
three phases. It will be reset automatically.
Compressor models SH180-240-295-300380-485 are delivered with a pre installed
motor protection module inside the terminal
box. This device provides for e cient and
reliable protection against overheating and
overloading (as well as phase loss/reversal on
SH240-295-300-380-485).
The motor protector comprises a control module
and PTC sensors embedded in the motor
winding. The close contact between thermistors
and windings ensures a very low level of thermal
inertia.
While not compulsory, an additional external
overload is still advisable for either alarm or
manual reset.
Then it must be set below MCC value (at max
operating current:
• when the motor temperature is too high, then
the internal protector will trip
• when the current is too high the external
overload protection will trip before the internal
protection therefore o ering possibility of
manual reset.
After this delay has elapsed, the relay is once
again pulled in – i.e. contacts M1-M2 (11-14
for SH180) are closed. The time delay may be
cancelled by means of resetting the mains (L-N
-disconnect) for approximately 5 sec.
A red/green twin LED is visible on the module.
A solid green LED denotes a fault free condition.
A blinking red LED indicates an identi able fault
condition:
PTC overheat
Phase sequence and reverse
rotation protection
20
The motor temperature is being constantly
measured by a PTC thermistor loop connected
on S1-S2 (called 1-2 on SH180). If any thermistor
exceeds its response temperature, its resistance
increases above the trip level (4,500 Ω) and the
output relay then trips – i.e. contacts M1-M2 (or
11-14 for SH180) are open. After cooling to below
the response temperature (resistance <2,750Ω),
a 5-minute time delay is activated.
Use a phase meter to establish the phase
orders and connect line phases L1, L2 and L3
to terminals T1, T2 and T3, respectively. The
compressor will only operate properly in a single
FRCC.PC .007.B8.02
Appr. 1 second
Delay timer active (after PTC over temp.)
Appr. 1 second
direction, and the motor is wound so that if the
connections are correct, the rotation will also be
correct.
Application guidelines
Electrical data, connections and wiring
Compressor models SH090-105-120-140-161-184
have no internal reverse rotation protection. If
reverse rotation occurs it will be obvious as soon
as power is turned on. The compressor will not
build-up any pressure, the sound level will be
abnormally high and power consumption will be
minimal. In such case, shut down the compressor
Compressor model SH180 incorporates an
internal reverse vent valve which will react in
the presence of reverse rotation and will allow
refrigerant to circulate through a by-pass from
the suction to the discharge. Although reverse
Compressor models SH 240 to 485 are delivered
with an electronic module which provides
protection against phase reversal and phase
loss at start-up. Apply the recommended wiring
diagrams from section "Suggested wiring
diagram logic". The circuit should be thoroughly
checked in order to determine the cause of the
phase problem before re energizing the control
circuit.
The phase sequencing and phase loss monitoring
functions are active during a 5-sec window 1
second after compressor start-up (power on
L1-L2-L3).
Compressor
start
Phase monitoring
Phase sequence module logic
0 1 s 6 s
immediately and connect the phases to their
proper terminals. Prolonged reverse rotation will
damage the compressor.
Phase sequence detector is strongly
recommended.
rotation is not destructive for the SH180, even
over long periods of time, it should be corrected
as soon as possible. If reverse rotation is not
halted, the SH180 will cycle o on the motor
protection.
Should one of these parameters be incorrect, the
relay would lock out (contact M1-M2 open). The
red led on the module will show the following
blink code:
In case of phase reverse error:
Appr. 1 second
In case of phase loss error:
Appr. 1 second
The lockout may be cancelled by resetting the
power mains (disconnect L-N) for approximately
5 seconds.
Voltage imbalance
The operating voltage limits are shown in the
table section "Motor voltage". The voltage applied
to the motor terminals must lie within these
table limits during both start-up and normal
operations. The maximum allowable voltage
imbalance is 2%. Voltage imbalance causes high
amperage over one or several phases, which in
turn leads to overheating and possible motor
damage. Voltage imbalance is given by the
formula:
2 x Vavg
V1-3 = Voltage between phases 1 & 3.
V2-3 = Voltage between phases 2 & 3.
21
Application guidelines
Approval and certifications
Approvals and
certi cates
Pressure Equipment
Directive 97/23/EC
Low voltage directive
2006/95/EC
SH scroll compressors comply with the following
approvals and certi cates.
Danfoss Commercial Compressors, along with
the whole refrigeration and air conditioning
industry, shares today’s concern about the
environmental issues that are ozone depletion,
global warming and overall energy consumption.
Usual HCFCs refrigerant uids such as R22
are known to be implicated in these harmful
phenomena, especially ozone depletion due to
their chlorinated content. These substances are
scheduled to be phased-out from production
• Refrigerant and lubricants
• Motor supply
• Compressor ambient temperature
• Application envelope (evaporating
temperature, condensing temperature, return
gas temperature)
Additional points could in uence the nal choice:
• Environmental considerations
• Standardisation of refrigerants and lubricants
• Refrigerant cost
• Refrigerant availability
and use in coming years, in accordance with the
international Montreal Protocol (1984).
As a result, new chlorine-free molecules have
been recently developed and are now ready to
replace former uids. Among those refrigerants,
the HFC blend R410A is admitted by a great
majority of manufacturers to be the most
promising in terms of environmental impact,
stability and e ciency, and is already seen as the
R22 replacement.
Cooling capacity of liquid (kJ/kg.K) at 25°C1.241.541.84
Cooling capacity of vapor (kJ/kg.K) at 1 atm, 25 °C0.6570.8290.833
Temperature glide (°C)07.4<0.2
SH compressors are to be used with R410A
refrigerant, with polyolester oil.
• R410A’s superior thermodynamical properties
compared to R22 and R407C refrigerants allow
for today’s massive – and necessary – switch to
high e ciency systems.
• Zero Ozone Depletion Potential (ODP): R410A
doesn’t harm the ozone layer.
• Global warming potential (GWP): R410A shows
a relatively high warming potential. However,
the GWP index denotes direct warming e ect,
which is relevant only in case of release to the
atmosphere. A more accurate index is T.E.W.I.,
for Total Equivalent Warming Impact, which
• Because of the higher system e ciency it allows
to achieve, R410A is in this regard the best
refrigerant.
• As a near-azeotropic mixture, refrigerant R410A
behaves like an homogeneous substance,
whereas other zeotropic mixtures such as
R407C and other blends su er a temperature
glide during phase change that lessens thermal
e ciency and makes them di cult to transfer
from a container to another.
• Reduced refrigerant mass ow, permitted by a
higher heat capacity, induce a lower sound level
of the installation as well as more compact and
lighter systems.
takes into account indirect contributions due to
running energy costs.
FRCC.PC .007.B8.02
23
Application guidelines
Operating conditions
POE oilPolyolester oil (POE) is miscible with HFC's
(while mineral oil is not), but has to be evaluated
regarding lubrication ability in compressors.
POE oil has better thermal stability than
refrigerant mineral oil.
Motor supply
SH scroll compressors can be operated at
nominal voltages as indicated section "Motor
voltage". Under-voltage and over-voltage
Compressor ambient
temperature
SH compressors can be applied from -35°C to
55°C ambient temperature for SH090-105-120140-161-184 and 51°C ambient temperature for
SH180-240-295-300-380-485. The compressors
High ambient temperature
In case of enclosed tting and high ambient
temperature, it’s recommend to check the
temperature of power wires and conformity to
their insulation speci cation.
Low ambient temperature
Although the compressor itself can withstand
low ambient temperature, the system may
require speci c design features to ensure safe
POE is more hygroscopic and also holds moisture
more tight than mineral oil.
It also chemically reacts with water leading to
acid and alcohol formation.
operation is allowed within the indicated voltage
ranges. In case of risk of under-voltage operation,
special attention must be paid to current draw.
are designed as 100 % suction gas cooled
without need for additional fan cooling.
Ambient temperature has very little e ect on the
compressor performance.
In case of safe tripping by the internal
compressor overload protection, the compressor
must cool down to about 60°C before the
overload will reset. A high ambient temperature
can strongly delay this cool-down process.
and reliable operation. See section ‘Speci c
application recommendations’.
Application envelope
The operating envelope for SH scroll compressors
is given in the gure below, where the
condensing and evaporating temperatures
represent the range for steady-state operation.
Under transient conditions, such as start-up and
defrost, the compressor may operate outside this
envelope for short periods.
The operating limits serve to de ne the
envelope within which reliable operations of the
compressor are guaranteed:
75
70
65
60
55
50
45
40
35
Condensing temperature (°C)
30
25
20
SH = 5 K
• Maximum discharge gas temperature: +135°C,
• A suction superheat below 5 K is not
recommended due to the risk of liquid ood
back,
• Maximum superheat of 30 K,
• Minimum and maximum evaporating and
condensing temperatures as per the operating
envelopes.
SH= 30K
SH= 11.1K
15
10
-35-30-25-20-15-10-505101520
24
FRCC.PC .007.B8.02
Evaporating temperature (°C)
Application guidelines
Operating conditions
Discharge temperature
protection
The discharge gas temperature must not exceed
135°C.
SH485includesa PTCsensor locatedinthe
xed scroll and wired in series with the motor
PTCthermistor chain. Excessivedischargetemperature will result
inelectronic module
outputrelay totrip.
For SH090to380, DGT protectionisrequiredif
the high and low pressure switch settings do
not protect the compressor against operations
beyond its speci c application envelope. Please
refer to the ex
amples below, which illustrate
where DGT protectionisrequired (Ex.1) and
whereitisnot (Ex.2).
A dischargegastemperatureprotectiondevice
must be installed on all heat pumps. In reversible
air-to-air and air-
to-water heat pumps the
discharge temperature must be monitored
during development test by the equipment
manufacturer.
Thermostat
Discharge line
Bracket
Insulation
The discharge gas thermostat accessory kit (code
7750009) includes all components required for
installation
as shown below. Th e thermostat must
beattachedtothedischarge line within 150mm
fromthe compressordischargeportandmust bethermally insulatedandtightly xed onthepipe.
The DGT s
hould besettoopenatadischargegas
temperatureof 135°C.
The compressor must not be allowed to cycle
on the discharge gas thermostat. Continuous
operations beyond the compressor’s operating
range will cause serious damage to the
compressor!
High and low pressure
protection
High pressure
70
65
Example 1 (R410A, SH = 11 K)
LP switch setting:
LP1 = 3.3 bar (g) (-15.5°C)
HP switch setting:
HP1 = 38 bar (g) (62°C)
Risk of operation beyondtheapplicationenvelope.
DGT protectionrequired.
Example2 (R410A, SH = 11 K)
LP switch setting:
LP2 = 4.6 bar
HP switch setting:
HP2 = 31 bar (g) (52°C)
Norisk of operation beyondtheapplicationenvelope.
No DGT protectionrequired .
(g) (-10.5°C)
A high-pressure (HP) safety switch
60
55
50
45
40
35
Cond. temp. (°C)
30
25
20
15
10
-30-25-20-15
is required to
shut down the compressor should the discharge
pressure exceed the values shown in the table
section "System pressure test". Th e high-pressure
switch can be set to lo
wer values depending on
the application and ambient conditions. The HP
Example 1
DGT - limit
LP1
LP2
-10
Evap. temp. (°C)
Example 2
R410A
-50 5101520
HP1
HP2
switch must either be placed in a lockout circuit
or consist of a manual reset device to prevent
cycling around the
high-pressure limit. If adischarge valveis used, the HP switch must be
connectedtotheservice valvegaugeport, which
mustnot beisolated.
FRCC.PC.007.B8.02
25
Application guidelines
T
Operating conditions
Internal pressure relief valve
Low pressure
The SH380 and SH485 incorporate an internal
relief valve set to open between the internal high
HP
and low pressure sides of the compressor when
the pressure di erential betw
een the discharge
and suction pressures surpasses 31 to 38 bar.
This safety feature prevents the compressor from
developing dangerously high pressures should
LP
Relief valve
the high pressure cut-out, for whateverreason,
fail toshutdownthe compressor.
A low-pressure (LP) safety switch must be used.
Deep vacuumoperationsof ascroll compressor
can causeinternal electrical arcingandscroll
instability. Danfoss SH scroll compressorsexhibit
high volumetric e
ciency and may draw very
low vacuum levels, which couldinducesuch
a problem. The minimum low-pressure safety
switch (loss-of-charge safety switch) setting is
PressuresettingsR410A
Workingpressurerange high side bar (g)13.5 - 44.5
Workingpressurerange low side bar (g)2.3 - 11.6
Maximum high pressuresafety switch setting bar (g)45
Minimum low pressuresafety s
Minimum low pressurepump-downswitch setting ** bar (g)2.3
* LP safety switch shall never be bypassedandshall havenotimedelay.
** Recommended pump-down switch settings
witch setting * bar (g)1.5
: 1.5 bar below nominal evap. pressure with minimumof 2.3 bar(g)
given in the following tabl
e. For systems without
pump-down, the LP safety switch must either be
a manual lockout device or an automatic switch
wired into an electrical lockout circuit. The LP
switch tolerance must not allow for vacuum
operations of the compressor. LP switch settings
for pump-down cycles with automatic reset are
also listed in the table below.
Cycle rate limit
Notet
hatthesetwodi erent low pressure
switches also require di erent settings. The low
pressure pump down switch setting must always
be within the operating envelope, for example
2.3 bar for R410A. The compressor can be
operated full time under such condition.
reverse compressor rotation, which may occur
during brief power interruptions.
The system must be designed in a way that
guarantees a minimum c
ompressor running
time of 2 minutes so as to provide for su cient
motor cooling after start-up along with proper oil
return. Note that the oil return may vary since it
depends upon system design.
The minimum low pressure safety switch setting
may be outside the normal operating envelope
and should only be reached in exceptional
(emergency)
situations, for example 1.5 bar for
R410A.
There m
ust benomorethan 12startsper hour, a
number higher than 12 reduces the service life of
the motor-compressor unit. A three-minute (180sec) time out is recommended.
~
KA
A1
H
TT
A2
TH
KA
~
A2 A3A1
180s
26
FRCC.PC.007.B8.02
Application guidelines
System design recommendations
General
Essential piping design
considerations
Successful application of scroll compressors
is dependent on careful selection of the
compressor for the application. If the compressor
is not correct for the system, it will operate
The working pressure in systems with R410A is
about 60% higher than in systems with R22 or
R407C. Consequently, all system components and
piping must be designed for this higher pressure
level.
Proper piping practices should be employed to
ensure adequate oil return, even under minimum
load conditions with special consideration given
to the size and slope of the tubing coming
from the evaporator. Tubing returns from the
evaporator should be designed so as not to trap
oil and to prevent oil and refrigerant migration
back to the compressor during o -cycles.
In systems with R410A, the refrigerant mass
ow will be lower compared to R22/R407C
systems. To maintain acceptable pressure
drops and acceptable minimum gas velocities,
the refrigerant piping must be reduced in size
beyond the limits given in this manual. Poor
performance, reduced reliability, or both may
result.
compared to R22 / R407C systems. Take care not
to create too high pressure drops since in R410A
systems the negative impact of high pressure
drops on the system e ciency is stronger than in
R22/R407C systems.
Piping should be designed with adequate threedimensional exibility. It should not be in contact
with the surrounding structure, unless a proper
tubing mount has been installed. This protection
proves necessary to avoid excess vibration, which
can ultimately result in connection or tube failure
due to fatigue or wear from abrasion. Aside from
tubing and connection damage, excess vibration
may be transmitted to the surrounding structure
and generate an unacceptable noise level within
that structure as well. For more information on
noise and vibration, see the section on: «Sound
and vibration management».
Suction lines
If the evaporator lies above the compressor, as
is often the case in split or remote condenser
systems, the addition of a pump-down cycle
is strongly recommended. If a pump-down
cycle were to be omitted, the suction line must
have a loop at the evaporator outlet to prevent
refrigerant from draining into the compressor
during o -cycles.
If the evaporator were situated below the
compressor, the suction riser must be trapped so
as to prevent liquid refrigerant from collecting at
the outlet of the evaporator while the system is
idle, which would mislead the expansion valve’s
sensor (thermal bulb) at start-up.
max. 4 m
max. 4 m
To condenser
HP
U-trap
0.5% slope
4 m/s or more
U-trap, as short as possible
8 to 12 m/s
0.5% slope
4m/s or more
U trap, as short as possible
LP
Evaporator
FRCC.PC .007.B8.02
27
Application guidelines
System design recommendations
Discharge lines
Heat exchangers
When the condenser is mounted at a higher
position than the compressor, a suitably sized
«U»-shaped trap close to the compressor is
necessary to prevent oil leaving the compressor
from draining back to the discharge side of the
compressor during o cycle. The upper loop also
helps avoid condensed liquid refrigerant from
draining back to the compressor when stopped.
To obtain optimum e ciency of the complete
refrigerant system, optimised R410A heat
exchangers must be used. R410A refrigerant has
good heat transfer properties: it is worthwhile
designing speci c heat exchangers to gain in size
and e ciency.
An evaporator with optimised R410A distributor
and circuit will give correct superheat at outlet
and optimal use of the exchange surface. This is
critical for plate evaporators that have generally
a shorter circuit and a lower volume than shell &
tubes and air cooled coils.
For all evaporator types a special care is required
for superheat control leaving the evaporator and
oil return.
Upper loop
HP
U Trap
Condenser
LP
3D flexibility
A sub-cooler circuit in the condenser that creates
high sub cooling will increase e ciency at high
condensing pressure. In R410A systems the
positive e ect of sub cooling on system e ciency
will be signi cantly larger than in R22/R407C
systems.
Furthermore, for good operation of the
expansion device and to maintain good
e ciency in the evaporator it is important
to have an appropriate sub cooling. Without
adequate sub cooling, ash gas will be formed at
the expansion device resulting in a high degree
of vapour at the expansion device inlet leading to
low e ciency.
Refrigerant charge limitDanfoss SH compressors can tolerate liquid
refrigerant up to a certain extend without major
problems. However, excessive liquid refrigerant in
the compressor is always unfavourable for service
life. Besides, the installation cooling capacity may
be reduced because of the evaporation taking
place in the compressor and/or the suction line
instead of the evaporator. System design must be
such that the amount of liquid refrigerant in the
compressor is limited. In this respect, follow the
guidelines given in the section: “Essential piping
design recommendations” in priority.
28
FRCC.PC .007.B8.02
Use the tables below to quickly evaluate the
required compressor protection in relation with
the system charge and the application.
ModelRefrigerant charge limit (kg)
SH0905.9
SH105-120-140-161-1847.9
SH180-240-295-30013.5
SH38014.5
SH48517
Application guidelines
System design recommendations
BELOW charge limitABOVE charge limit
Cooling only systems,
Packaged units
Cooling only systems
with remote condenser
and split system units
Reversible heat pump system
O -cycle migration
Refrigerant migration & ood back test
No test or additional safeties required
Refrigerant migration & ood back test
REC
Sump heater
REC
Speci c tests for repetitive ood back
REQ
Sump heater
REQ
Defrost test For more details, refer to section "Reversible heat pump system"
REQ
RecommendedRequiredNo test or additional safeties required
REC
Note: for special conditions such as low ambient temperature, low refrigerant load or brazed plate heat exchangers please refer
to corresponding sections.
REQ
REQ
Sump heater
REQ
Refrigerant migration & ood back test
REQ
Sump heater
REQ
Liquid receiver (in association with LLSV and pump
REC
down)
More detailed information can be found in the paragraphs hereafter.
Please contact Danfoss Technical Support for any deviation from these guidelines.
O -cycle refrigerant migration is likely to occur
when the compressor is located at the coldest
A suitable test to evaluate the risk of o -cycle
migration is the following:
part of the installation, when the system uses
a bleed-type expansion device, or if liquid is
allowed to migrate from the evaporator into
Stabilize the non running system at 5°C ambient
temperature,
the compressor sump by gravity. If too much
liquid refrigerant accumulates in the sump it
will saturate the oil and lead to a ooded start:
Raise the ambient temperature to 20°C and keep
it for 10 minutes,
when the compressor starts running again, the
refrigerant evaporates abruptly under the sudden
decrease of the bottom shell pressure, causing
the oil to foam. In extreme situations, this might
Start the compressor and monitor sump
temperature, sight glass indication and sound
level.
result in liquid slugging (liquid entering the scroll
elements), which must be avoided as it causes
irreversible damage to the compressor.
The presence of liquid in the crankcase can be
easily detected by checking the sump level
through the oil sight glass. Foam in the oil sump
Danfoss SH scroll compressors can tolerate
indicates a ooded start.
occasional ooded starts as long as the total
system charge does not exceed the maximum
compressor refrigerant charge.
A noisy start, oil loss from the sump and sump
cool down are indications for migration.
Depending on the amount of migration graduate
measures shall be taken:
• Sump heater
• Liquid line solenoid valve
• Pump down cycle
FRCC.PC .007.B8.02
29
Application guidelines
System design recommendations
Sump heaterThe surface sump heaters are designed to protect
the compressor against o -cycle migration of
refrigerant.
When the compressor is idle, the oil temperature
in the sump of the compressor must be
maintained at no lower than 10 K above the
saturation temperature of the refrigerant on the
low-pressure side. This requirement ensures that
the liquid refrigerant is not accumulating in the
sump. A sump heater is only e ective if capable
of sustaining this level of temperature di erence.
Tests must be conducted to ensure that the
appropriate oil temperature is maintained under
all ambient conditions (temperature and wind).
Note that below –5°C ambient temperature and a
wind speed of above 5m/second, we recommend
that the heaters be thermally insulated in order
to limit the surrounding energy losses.
Since the total system charge may be unde ned,
a sump heater is recommended on all standalone compressors and split systems. In addition,
any system containing a refrigerant charge in
excess of the maximum recommended system
charge for compressors requires a sump heater.
A sump heater is also required on all reversible
cycle applications.
At initial start-up or after power shortage, it is
recommended to energize surface sump heater
to remove refrigerant 6 hours in advance. A
quicker start-up is possible by "jogging" the
compressor to evacuate refrigerant in the
compressor. Start the compressor for 2 or 3
seconds, then wait for 1 to 2 minutes. After 3 or 4
jogs the compressor can be started.
The heater must be energized whenever the
compressor is o to avoid liquid refrigerant
entering the compressor.
Provide separate electrical supply for the heaters
so that they remain energized even when
the machine is out of service (eg. Seasonal
shutdown).
Surface sump heater accessories are available
from Danfoss (see section "Accessories").
Liquid line solenoid valve
(LLSV)
A LLSV may be used to isolate the liquid charge
on the condenser side, thereby preventing
against charge transfer or excessive migration to
the compressor during o -cycles. The quantity of
Pump-down cycleA pump-down cycle represents one of the most
e ective ways to protect against the o -cycle
migration of liquid refrigerant. Once the system
has reached its set point and is about to shut
o , the LLSV on the condenser outlet closes.
The compressor then pumps the majority of
the refrigerant charge into the condenser and
receiver before the system stops on the low
pressure pump-down switch. This step reduces
the amount of charge on the low side in order to
prevent o -cycle migration. The recommended
low-pressure pump-down switch setting is 1.5
bar below the nominal evaporating pressure.
It shall not be set lower than 2.3 bar(g). For
suggested wiring diagrams, please see section
"Suggested wiring diagrams logic".
refrigerant on the low-pressure side of the system
can be further reduced by using a pump-down
cycle in association with the LLSV.
In certain conditions, the discharge valve in the
SH090 - 105 - 120 - 140 - 161 - 184 compressor
may not completely seal and result in compressor
restarts during pump down applications. An
external, non-bleeding check valve may need to
be installed.
Tests for pump down cycle approval:
• As the pump-down switch setting is inside the
application envelope, tests should be carried
out to check unexpected cut-out during
transient conditions (ie. defrost – cold starting).
When unwanted cut-outs occur, the low
pressure pump-down switch can be delayed. In
this case a low pressure safety switch without
any delay timer is mandatory.
30
FRCC.PC .007.B8.02
Application guidelines
System design recommendations
Liquid ood back
• While the thermostat is o , the number of
pressure switch resets should be limited to
avoid short cycling of the compressor. Use
dedicated wiring and an additional relay which
allows for one shot pump-down.
The pump-down allows to store all the refrigerant
in the high pressure side circuit. On unitary
or close-coupled systems, where the system
refrigerant charge is expected to be both correct
and de nable the entire system charge may be
stored in the condenser during pump-down if all
components have been properly sized.
During normal operation, refrigerant enters the
compressor as a superheated vapour. Liquid
ood back occurs when a part of the refrigerant
entering the compressor is still in liquid state.
Danfoss SH scroll compressors can tolerate
occasional liquid ood back. However, system
Liquid ood back test - Repetitive liquid
ood back testing must be carried out under
expansion valve threshold operating conditions:
a high pressure ratio and minimum evaporator
load, along with the measurement of suction
superheat, oil sump temperature and discharge
gas temperature.
During operations, liquid ood back may be
detected by measuring either the oil sump
temperature or the discharge gas temperature.
If at any time during operations, the oil sump
temperature drops to within 10K or less above
Other application needs a liquid receiver to store
the refrigerant.
Receiver dimensioning requires special attention.
The receiver shall be large enough to contain
part of the system refrigerant charge but it shall
not be dimensioned too large. A large receiver
easily leads to refrigerant overcharging during
maintenance operation.
design must be such that repeated and excessive
ood back is not possible.
A continuous liquid ood back will cause oil
dilution and, in extreme situations lead to lack
of lubrication and high rate of oil leaving the
compressor.
the saturated suction temperature, or should
the discharge gas temperature be less than 35K
above the saturated discharge temperature, this
indicates liquid ood back.
Continuous liquid ood back can occur with
a wrong dimensioning, a wrong setting or
malfunction of the expansion device or in case of
evaporator fan failure or blocked air lters.
A suction accumulator providing additional
protection as explained hereunder can be used
to solve light continuous liquid ood back.
Suction accumulator: a suction accumulator
o ers protection against refrigerant ood back
at start-up, during operations or defrosting by
trapping the liquid refrigerant upstream from
the compressor. The suction accumulator also
protects against o -cycle migration by providing
additional internal free volume to the low side of
the system.
A suction accumulator must be carefully
dimensioned, taking into account the refrigerant
charge as well as the gas velocity in the suction
line.
FRCC.PC .007.B8.02
The accumulator should not be sized for less than
50 % of the total system charge. Tests must be
conducted to determine the actual refrigerant
holding capacity needed for the application.
Depending on the operating conditions it may
happen that the recommended connections of
the accumulator are one size smaller than the
suction line.
31
Application guidelines
Low ambient application
Low ambient start-up
Specific application recommendations
Under cold ambient conditions (<0°C), upon
start-up the pressure in the condenser may be so
low that a su cient pressure di erential across
the expansion device cannot be developed to
properly feed the evaporator.
As a result, the compressor may go into a deep
vacuum, which can lead to compressor failure
due to internal arcing and instability in the
scroll wraps. Under no circumstances should
the compressor be allowed to operate under
vacuum. The low-pressure control must be set in
accordance with the table section "Low pressure"
in order to prevent this from happening.
Early feeding of the evaporator and management
of the discharge pressure could help to attenuate
these e ects.
Low pressure di erentials can also cause
the expansion device to «hunt» erratically,
which might cause surging conditions within
the evaporator, with liquid spillover into the
compressor. This e ect is most pronounced
during low load conditions, which frequently
occur during low ambient conditions.
Low ambient operations
The Danfoss SH scroll compressor requires a
minimum pressure di erential of 6 to 7 bar
between the suction and discharge pressures
to force the orbiting scroll down against the
oil lm on the thrust bearing. Anything less
than this di erential and the orbiting scroll
can lift up, causing a metal-to-metal contact.
It is therefore necessary to maintain su cient
discharge pressure in order to ensure this
pressure di erential. Care should be taken during
low ambient operations when heat removal
from air-cooled condensers is greatest and
head pressure control may be required for low
ambient temperature applications. Operation
under low pressure di erential may be observed
by a signi cant increase in the sound power level
generated by the compressor.
It is recommended that the unit be tested and
monitored at minimum load and low ambient
conditions as well. The following considerations
should be taken into account to ensure proper
system operating characteristics.
Expansion device: The expansion device
should be sized to ensure proper control of
the refrigerant ow into the evaporator. An
oversized valve may result in erratic control.
This consideration is especially important in
manifolded units where low load conditions may
require the frequent cycling of compressors.
This can lead to liquid refrigerant entering the
compressor if the expansion valve does not
provide stable refrigerant super-heat control
under varying loads.
The superheat setting of the expansion device
should be su cient to ensure proper superheat
levels during low loading periods. A minimum of
5 K stable superheat is required.
Head pressure control under low ambient
conditions: Several possible solutions are
available to prevent the risk of compressor to
vacuum and low pressure di erential between
the suction and discharge pressures.
In air-cooled machines, cycling the fans with
a head pressure controller will ensure that the
fans remain o until the condensing pressure
has reached a satisfactory level. Variable speed
fans can also be used to control the condensing
pressure. In water-cooled units, the same can be
performed using a water regulator valve that is
also operated by head pressure, thereby ensuring
that the water valve does not open until the
condensing pressure reaches a satisfactory level.
The minimum condensing pressure must be
set at the minimum saturated condensing
temperature shown in the application envelopes.
Under very low ambient conditions, in which
testing has revealed that the above procedures
might not ensure satisfactory condensing and
suction pressures, the use of a head pressure
control valve is recommended. Note: This
solution requires extra refrigerant charge, which
can introduce other problems. A non-return
valve in the discharge line is recommended and
special care should be taken when designing the
discharge line.
For further information, please contact Danfoss.
32
FRCC.PC .007.B8.02
Application guidelines
Specific application recommendations
Sump heaters
Low load operation
Brazed plate
heat exchangers
Sump heaters are strongly recommended on
all systems where the compressor is exposed to
low ambient temperatures, especially split and
remote condenser installations. The sump heater
The compressors should be run for a
minimum period in order to ensure that the
oil has su cient time to properly return to the
A brazed plate heat exchanger needs very little
internal volume to satisfy the set of heat transfer
requirements. Consequently, the heat exchanger
o ers very little internal volume for the
compressor to draw vapour from on the suction
side. The compressor can then quickly enter into
a vacuum condition. It is therefore important
that the expansion device is sized correctly and
that a su cient pressure di erential across the
expansion device is available to ensure adequate
refrigerant feed into the evaporator. This aspect is
of special concern when operating the unit under
low ambient and load conditions. For further
information on these conditions, please refer to
the previous sections.
will minimize refrigerant migration caused by
the large temperature gradient between the
compressor and the remainder of the system,
please refer to section "Accessories".
compressor sumps and that the motor has
su cient time to cool under conditions of lowest
refrigerant mass ows.
Due to the small volume of the brazed plate heat
exchanger, no pump-down cycle is normally
required. The suction line running from the heat
exchanger to the compressor must be trapped to
avoid refrigerant migration to the compressor.
When using a brazed plate condenser heat
exchanger, a su cient free volume for the
discharge gas to accumulate is required in order
to avoid excess pressure build-up. At least 1
meter of discharge line is necessary to generate
this volume. To help reduce the gas volume
immediately after start-up even further, the
supply of cooling water to the heat exchanger
may be opened before the compressor starts
up so as to remove superheat and condense the
incoming discharge gas more quickly.
Electronic expansion
valve
Reversible heat pump
systems
The use of an electronic expansion valve requires
a speci c compressor start / stop control.
A specific compressor start sequence control has
to be set when an electronic expansion valve
(EXV) is used. The sequence must be adjusted
according to the EXV step motor speed to allow
time for the EXV to open before the compressor
starts to avoid running under vacuum conditions.
The EXV should be closed at compressor stop
not to let refrigerant in liquid phase entering the
Transients are likely to occur in reversible heat
pump systems, i.e. a changeover cycle from
cooling to heating, defrost or low-load short
cycles. These transient modes of operation
may lead to liquid refrigerant carry-over (or
ood back) or excessively wet refrigerant return
conditions. As such, reversible cycle applications
require speci c precautions for ensuring a long
compressor life and satisfactory operating
characteristics. Regardless of the refrigerant
compressor. Ensure that the EXV closes when the
supply voltage to the controller is interrupted (ie
power cut o ) by the use of a battery back up.
EXV Opened
Closed
Compressor On
O
charge in the system, speci c tests for repetitive
ood back are required to con rm whether or not
a suction accumulator needs to be installed.
The following considerations cover the most
important issues when dealing with common
applications. Each application design however
should be thoroughly tested to ensure
acceptable operating characteristics.
FRCC.PC .007.B8.02
33
Application guidelines
Specific application recommendations
Sump heatersSump heaters are mandatory on reversible
cycle applications given the high probability of
liquid migration back to the compressor sump
Discharge temperature
thermostat
Heat pumps frequently utilize high condensing
temperatures in order to achieve a su cient
temperature rise in the medium being heated.
At the same time, they often require low
evaporating pressures to obtain su cient
temperature di erentials between the evaporator
and the outside temperature. This situation may
result in high discharge temperature; as such,
it is mandatory that a discharge gas thermostat
be installed on the discharge line to protect
Discharge line, reversing
valve, solenoid valves
The Danfoss SH scroll compressor is a high
volumetric machine and, as such, can rapidly
build up pressure in the discharge line if gas
in the line becomes obstructed even for a very
short period of time which situation may occur
with slow-acting reversing valves in heat pumps.
Discharge pressures exceeding the operating
envelope may result in nuisance high-pressure
switch cutouts and place excess strain on both
the bearings and motor.
To prevent such occurrences, it is important that
a 1-meter minimum discharge line length be
allowed between the compressor discharge port
and the reversing valve or any other restriction.
This gives su cient free volume for the discharge
gas to collect and to reduce the pressure peak
during the time it takes for the valve to change
position. At the same time, it is important that
the selection and sizing of the reversing or 4-way
valve ensure that the valve switches quickly
enough to prevent against too high discharge
pressure and nuisance high-pressure cutouts.
during o -cycles due to the outdoor location of
most units and operations during low ambient
conditions.
the compressor from excessive temperatures.
Operating the compressor at too high discharge
temperatures can result in mechanical damage
to the compressor as well as thermal degradation
of the compressor lubricating oil and a lack
of su cient lubrication. The discharge gas
thermostat should be set to shut down the
compressor in the event discharge gas rises
above 135°C.
Check with the valve manufacturer for optimal
sizing and recommended mounting positions.
Additionally, in order to make a smooth
transition when beginning & ending defrost ,
it is recommended to stop compressors when
deciding to move 4-way valve:
• rst stop compressors
• wait 10 seconds
• move the 4-way valve
• wait 10 seconds
• restart the compressors
In applications with heat recovery or condenser
partialisation, servo piloted solenoid valve has
to be properly sized or associated with a second
small valve in parallel, in order to avoid quick
discharge pressure drops when opening. This
phenomenon could lead to hammering e ects
and create constraints on the non return valve
integrated in discharge tting (SH180 to 380).
Defrost and reverse cycleThe Danfoss SH scroll compressor has the
ability to withstand a certain amount of liquid
refrigerant dynamic slug. However we advise that
34
FRCC.PC .007.B8.02
the system is unloaded to the minimum capacity
step for defrost or when the cycle is reversed.
Application guidelines
Specific application recommendations
Suction line accumulator
Water utilizing systems
The use of a suction line accumulator is strongly
recommended in reversible-cycle applications.
This because of the possibility of a substantial
quantity of liquid refrigerant remaining in the
evaporator, which acts as a condenser during the
heating cycle.
This liquid refrigerant can then return to the
compressor, either ooding the sump with
refrigerant or as a dynamic liquid slug when
Apart from residual moisture in the system
after commissioning, water could also enter the
refrigeration circuit during operation. Water in
the system shall always be avoided. Not only
because it can shortly lead to electrical failure,
sludge in sump and corrosion but in particular
because it can cause serious safety risks.
Common causes for water leaks are corrosion and
freezing.
the cycle switches back to a defrost cycle or to
normal cooling operations.
Sustained and repeated liquid slugging and
ood back can seriously impair the oil’s ability
to lubricate the compressor bearings. This
situation can be observed in wet climates where
it is necessary to frequently defrost the outdoor
coil in an air source heat pump. In such cases a
suction accumulator becomes mandatory.
Corrosion: Materials in the system shall be
compliant with water and protected against
corrosion.
Freezing: When water freezes into ice its volume
expands which can damage heat exchanger
walls and cause leaks. During o periods water
inside heat exchangers could start freezing when
ambient temperature is lower than 0°C. During
on periods ice banking could occur when the
circuit is running continuously at too low load.
Both situations should be avoided by connecting
a pressure and thermostat switch in the safety
line.
FRCC.PC .007.B8.02
35
Application guidelines
Sound and vibration management
Starting sound level
Running sound level
During start-up transients it is natural for
the compressor sound level to be slightly
higher than during normal running. SH scroll
compressors exhibit very little increased start-up
transient sound. If a compressor is miswired,
compressor rotation is characterized by an
objectionable sound. To correct reverse rotation,
disconnect power and switch any two of the
three power leads at the unit contactor. Never
switch leads at the compressor terminals.
the compressor will run in reverse. Reverse
Compressor acoustic hoods have been
developed to meet speci c extra-low noise
incorporate sound proo ng materials and o er
excellent high and low frequency attenuation.
requirements. The covers and bottom insulations
50 Hz60 Hz
Model
SH090706726120Z0034
SH10571.56746120Z0035
SH12072.56756120Z0035
SH140 *72.56766120Z0035
SH161 *73.56776120Z0035
SH184756786120Z0135
SH180806854120Z0022120Z0353
SH240826864120Z0022120Z0353
SH295826864120Z0022120Z0353
SH300826864120Z0022120Z0353
SH380
SH485894914120Z0022120Z0353
Sound power and attenuation are given at ARI conditions, measured in free space
* For SH140 code 3 and SH161 code 3 use acoustic hood reference 120Z0135
Attenuation given with acoustic hood only
Bottom hood is provided in surface sump heater accessories for SH180-240-295-300-380-485 models. Additional attenuation
is 2 to 4 dBA.
Materials are UL approved and RoHS compliant
Sound power
dB(A)
836874120Z0022120Z0353
Attenuation
dBA
Sound power
dB(A)
Attenuation
dbA
Acoustic hood
code number
Bottom hood
code n°
Not available
Stopping sound level
Sound generation in a
refrigeration or air
conditioning system
SH compressors are equipped with a discharge
valve which closes at compressor shut down
and thus prevents the compressor from running
backwards. This reduces the stopping sound to a
metallic click caused by the closing valve.
Typical sound and vibration in refrigeration and
air conditioning systems encountered by design
and service engineers may be broken down into
the following three source categories.
Sound radiation: this generally takes an airborne
path.
When the pressure di erence or gas ow at shut
down should be very low, this can delay the
discharge valve from closing and lead to a longer
noise duration.
Mechanical vibrations: these generally extend
along the parts of the unit and structure.
Gas pulsation: this tends to travel through the
cooling medium, i.e. the refrigerant.
The following sections focus on the causes and
methods of mitigation for each of the above
sources.
36
FRCC.PC .007.B8.02
Application guidelines
Sound and vibration management
Compressor sound radiationFor sound radiating from the compressor, the
emission path is airborne and the sound waves
are travelling directly from the machine in all
directions.
The Danfoss SH scroll compressor is designed
to be quiet and the frequency of the sound
generated is pushed into the higher ranges,
which not only are easier to reduce but also do
not generate the penetrating power of lowerfrequency sound.
Use of sound-insulation materials on the inside of
unit panels is an e ective means of substantially
reducing the sound being transmitted to the
outside. Ensure that no components capable
of transmitting sound/vibration within the unit
come into direct contact with any non-insulated
parts on the walls of the unit.
Mechanical vibrations
Vibration isolation constitutes the primary
method for controlling structural vibration.
Danfoss SH scroll compressors are designed to
produce minimal vibration during operations.
The use of rubber isolators on the compressor
base plate or on the frame of a manifolded unit
is very e ective in reducing vibration being
transmitted from the compressor(s) to the unit.
Once the supplied rubber grommets have been
properly mounted, vibrations transmitted from
the compressor base plate to the unit are held
to a strict minimum. In addition, it is extremely
important that the frame supporting the
mounted compressor be of su cient mass and
sti ness to help dampen any residual vibration
potentially transmitted to the frame. For further
Because of the unique Danfoss design of a
full-suction gas-cooled motor, compressor
body insulation across its entire operating
range is possible. Acoustic hoods are available
from Danfoss as accessories. They have been
developed to meet speci c extra low noise
requirements. They incorporate sound proo ng
materials and o er excellent high and low
frequency alternative.
These hoods are quick and easy to install and do
not increase the overall size of the compressors
to a great extend.
Refer to section "Running sound level" for sound
attenuation and code numbers.
information on mounting requirements, please
refer to the section on mounting assembly.
Note: for parallel assemblies see speci c
recommendations in Danfoss SH parallel
application guidelines FRCC.PC.008 (rigid
mounting).
The tubing should be designed so as to both
reduce the transmission of vibrations to other
structures and withstand vibration without
incurring any damage. Tubing should also be
designed for three-dimensional exibility. For
more information on piping design, please see
the section entitled “Essential piping design
considerations”.
Gas pulsation
The Danfoss SH scroll compressor has been
designed and tested to ensure that gas pulsation
has been optimised for the most commonly
encountered air conditioning pressure ratio. On
heat pump installations and other installations
where the pressure ratio lies beyond the
typical range, testing should be conducted
FRCC.PC .007.B8.02
under all expected conditions and operating
con gurations to ensure that minimum gas
pulsation is present. If an unacceptable level
is identi ed, a discharge mu er with the
appropriate resonant volume and mass should
be installed. This information can be obtained
from the component manufacturer.
37
Application guidelines
Installation
Compressor handling and
storage
Each SH compressor is shipped with printed
Instructions for installation. These instructions
can also be downloaded from our web site:
Each Danfoss SH scroll compressor is equipped
with two lift rings on the top shell. Always use
both these rings when lifting the compressor.
Use lifting equipment rated and certi ed for
the weight of the compressor. 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 and certi ed to lift the weight of
the compressor is also highly recommended.
Always respect the appropriate rules concerning
lifting objects of the type and weight of these
compressors. Maintain the compressor in an
upright position during all handling manoeuvres
(maximum of 15° from vertical).
Never use only one lifting lug to lift the
compressor. The compressor is too heavy for the
single lug to handle, and the risk is run that the
lug could separate from the compressor with
extensive damage and possible personal injury
as a result.
www.danfoss.com or directly from:
http://instructions.cc.danfoss.com
refrigerant and between -35°C and 70°C when
charged with nitrogen.
When the compressor is mounted as part
of an installation, never use the lift rings on the
compressor to lift the installation. The risk is run
that the lugs could separate from the compressor
or that the compressor could separate from the
base frame with extensive damage and possible
personal injury as a result.
Never apply force to the terminal box with the
intention of moving the compressor, as the
force placed upon the terminal box can cause
extensive damage to both the box and the
components contained inside.
HEAVY
Compressor mounting
Mounting of SH090-105-12 0-
140-161 -184
Store the compressor not exposed to rain,
corrosive or ammable atmosphere and between
do not lift
manually
-35°C and 51°C when charged with R410A
Maximum inclination from the vertical plane while operating must not exceed 3 degrees.
Compressors SH090-105-120-140-161-184 come
delivered with four rubber mounting grommets
and metal sleeve liners that serve to isolate
The required bolt size for the SH 090 -105-120140-161-184 compressors is HM8-40. This bolt
must be tightened to a torque of 15 Nm.
the compressor from the base frame. These
grommets must always be used to mount the
compressor in a single application. The grommets
must be compressed until contact between the
at washer and the steel mounting sleeve is
established. The grommets attenuate to a great
extent the transmission of compressor vibrations
to the base frame.
For parallel assemblies see speci c
recommendations in Danfoss SH parallel
application guidelines (rigid mounting).
HM 8 bolt
Lock washer
Flat washer
Steel mounting
sleeve
Rubber grommet
Nut
15 mm
38
When a surface sump heater is used, it must be
applied after the grommets are mounted on
FRCC.PC .007.B8.02
compressor feet, in order to avoid surface sump
heater damage.
Application guidelines
Installation
Mounting of SH180-240295-300-380-485
CompressorsSH180-240-295-300-380-485come
delivered withrigid mountingspacers for parallel
mounting.
If used in single applications, the compressor
must be mounted with the exibl
e grommets as
available in accessory conversion kit 8156138.
Thegrommetsmustbecompressed until contact
1 manifoldablecompressor
with rigid spacers
between the at washer and the steel mounting
sleeve is established. The grommets attenuate
to a great extent the transmission
nitrogen holding charge between 0.3 and 0.7 bar
and is sealed with elastomer plugs.
Before the suction and discharge plugs are
removed, the nitrogen holding charge must be
released via the suction
schrader valve to avoid
an oil mist blowout. Remove the suction plug
Rubber grommets from
kit 8156138
HM 8 bolt
Lock washer
Flat washer
Steel mounting sleeve
Rubber grommet
Nut
Compressor
base plate
28 mm
rstand the discharge plugafterwards. The plugs
shall be removed only just before connecting the
compressor to the installation in order to
avoid
moisture from entering the compressor. When
the plugs are removed, it is essential to keep the
compressor in an upright position so as to avoid
oil spillage.
FRCC. PC.007.B8.02
39
Application guidelines
Installation
System cleanliness
The refrigerant compression system, regardless
of the type of compressor used, will only provide
high e ciency and good reliability, along with a
long operating life, if the system contains solely
the refrigerant
and oil it was designed for. Any
other substances within the system will not
improve performance and, in most cases, will be
highly detrimental to system operations.
The presence of non-condensable substances
and system contaminants such as
metal
shavings, solder and ux, have a negative
impact on compressor service life. Many of these
contaminants are small enough to pass through a
mesh screen and can cause considerable damage
within a bearing assembly.
The useo
f highly hygroscopic polyolesteroil
in R410A compressors requires that the oil be
exposed to the atmosphere as little as possible.
Tubi ngOnly use clean and dehydrated refrigeration-
grade copper tubing. Tube-cutting must be
carried out so as not to deform the tubing
roundness and to ensure that no foreign debris
remains within the tubing. Only
ttings should be used and these must be of
refrigerant grade
System contamination is one of main factors
a ecting equipment reliability and compressor
ser
vice life. It is important therefore to take
system cleanliness into account when assembling
a refrigeration system.
During the manufacturing process, circuit
contamination may be caused by:
• Brazingand weldingoxides,
• Filings and particles from the removal of burrs
in pipe-work,
• Brazing ux,
• Moistureand air.
Consequently, whenbuildingequipmentand assemblies, the precautions listed inthe
following paragraphsmustbetaken
.
botha designand sizetoallow foraminimum
pressure drop throughthecompleted assembly.
Followthebrazinginstructionsonnext pages.
Never
temperature is reached. Move the torch to
area and apply heat evenly until the brazing
temperature has been reached there as well,
and then begin adding the brazing material.
Mov
e the torch evenly around the joint, in
applying only enough brazing material to ow
the full circumference of the joint.
.Movethetorchtoareaonly longenoughto
draw the brazing material into the joint, but not
into the compressor.
.Remove all remaining ux once the joint has
been soldered with a wire brush or a wet cloth.
Remaining ux would cause corrosion of the
tubing.
In addition, for discharge connections equipped
with a non return valve integrated in discharge
tting (SH180 to SH485) the direction of the
torch has to be as described on the picture, and
maximum brazing time should be less than 2
minutes to avoid NRVI damages.
Ensure that no ux is allowed to enter into the
tubing or compressor. Flux is acidic and can cause
substantial damage to the internal parts of the
system and compressor.
The polyolester oil used in SH compressors
is highly hygroscopic and will rapidly absorb
moisture from the
air. The compressor must
therefore not be left open to the atmosphere
fora long period of time. Thecompressor tting
plugsshall beremoved justbeforebrazingthe
compressor. The compressor should always be
the last component brazed into the system
Before eventual unbrazing the compressor or
any system component, the refrigerant charge
must be removed from both the high- and
low-pressure sides. Failure to do so may result in
serious personal injury. Press
uregaugesmustbe
used toensureall pressuresareatatmospheric
level.
Formore detailed informationontheappropriate
materials required for brazing or soldering, please
contact the product manufacturer or
distributor.
Forspeci capplicationsnotcovered herein,
pleasecontact Danfoss for furtherinformation.
System pressure testAlways useaninertgassuchasnitrogen for
pressure testing. Never use other gasses such as
oxygen, dry air or acetylene as these may form
Maximum compressor test pressure (low side)
Maximum compressor test pressure (high side)45 bar (g)
Maximum pressure di erence between high & low side
compressor
FRCC. PC.007.B8.02
of the
an in ammable mixture. Do not exceed the
following pressures
:
30.2 bar (g) forSH180 to 485
33.3 bar(g) forSH090 to 184
37 bar
41
Application guidelines
Installation
Leak detection
Vacuum evacuation and
moisture removal
Pressurize the system on HP side rst then LP side
to prevent rotation of the scroll. Never let the
pressure on LP side exceed the pressure on HP
side with more than 5 bar.
tting or if an external non return valve is present
on the discharge line, we advise to pressurize
the system not quicker than 4.8 bar/s to all
pressure equalization between LP and HP side
over scroll elements.
OnSH180-240-295-300-380-485mo
delswhich
haveaninternal nonreturn valvein discharge
Leak detectionmustbecarried out usinga
mixture of nitrogen and refrigerant or nitrogen
and helium, as indicated in the table below.
Ne
Note 1: Leak detectionwithrefrigerantmay be forbiddeninsomecountries. Check local regulations.
Note 2: The use of leak detecting additives is not recommended as the
Moisture obstructs the proper functioning of the
com
pressor and the refrigeration system.
or acetylene as these may form an in ammable
mixture.
Pressurize the system on HP side rst then LP
side.
y may a ect the lubricant properties.
SH compressors are delivered with < 100 ppm
moisture level. The required moisture level in the
circuit after vacuum dehydration must be < 100
Air and moisture reduce service life and increase
condensing pressure, and cause excessively high
dischargetemperatures, whichcan destroy the
lubricating propertiesof theoil. Airand moisture
a
lso increase the risk of acid formation, giving
rise to copper platting. All these phenomena
can cause mechanical and electrical compressor
ppm forsystems
• Never usethecompressortoevacuatethesystem.
• Connect a vacuum pump to both the LP & HP sides.
• Evacuate the system to a pressure of 500 μm
Hg (0.67 mbar) absolute.
withanSH.
failure.
Donot useamegohmmeter
Forthesereasonsit’s important to perform a
vacuum dehydrationonthesystemtoremove
the compressor while it’s under vacuum as this
may cause internal damage.
all residual moisture from the pipe-work after
assembly;
ow
nor apply power to
Filter driersA properly sized & type of drier is required.
Important selection criteria include the driers
water content capacity, the system refrigeration
capacity and the system refrigerant charge.
The drier must be able to reach and maintain
a moisture level of 50 ppm end point dryness
rier is to be oversized rather than under
sized. When selecting a drier, always take into
account its capacity (water content capacity),
the system refrigeration capacity and the system
refrigerant charge.
After burn ou
t, remove & replace the liquid line
lter drier and install a Danfoss type DAS burnout drier of the appropriate capacity. Refer to the
DAS drier instructions and technical information
forcorrect useof theb
urnout drieronthe liquid
line.
Application guidelines
Installation
Refrigerant charging
Insulation resistance and
dielectric strength
For the initial charge the compressor must not
run and eventual service valves must be closed.
Charge refrigerant as close as possible to the
nominal system charge before starting the
compressor. This initial charging o
be done in liquid phase. The best location is on
the liquid line between the condenser outlet
and the lter drier. Then during commissioning,
when needed, a complement of charge can be
done in liquid phase: slowly
on the low pressure side as far away as possible
from the compressor suction connection while
compressor is running. The refrigerant charge
quantity must be suitable for both summer and
winter o
Insulation resistance must be higher than 1
megohm when measured with a 500 volt direct
current 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
an
mA.
SH scroll compressors are con 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
motor windings will result in lower resistance
mended refrigerant system charging practice"
news bulletin FRCC.EN.050.
values to ground and higher leakage current
readings. Such readings do not indicate a faulty
compressor.
In testing insulation resistance, Danfoss
recommends
brie y to distribute refrigerant throughout the
system. Following this brief operation, retest the
compressor for insulation resistance or current
leakage.
Never reset a breaker or replace a fuse withou
rst checking for a ground fault (a short circuit to
ground). Be alert for sounds of arcing inside the
compressor.
runs up to 20 m, no additional oil is required. If
installation lines exceed 20 m, additional oil may
be needed. 1 or 2% of the total system refrigerant
charge (in weight) can be used to rou
the required oil top-up quantity but in any case
the oil charge has to be adjusted based on the oil
conditions
sight glass.
The presence of foam lling in the sight glass
indicates large concentration of refrigerant in the
oil and / or presence of liquid returning to the
compressor.
the oil level must be visible in the
within
ghly de ne
• Low foaming in sight glass and compressor
sump temperature 10K above saturation
temperature to show that there is no
refrigerant migration taking place
• Acceptable cycling rate of compressors,
including duration of run times
• Current draw of individual compressors within
acceptable values (max operating current)
• Noabnormal vibrationsand noise.
Theoil lev
afterthecompressorstops.
Whenthecompressoriso , the level in the
sight glass can be in uenced by the presence of
refrigerant in the oil.
Always use original Dan
new cans.
Top-up the oil while the compressor is idle. Use
the schrader connector or any other accessible
connector on the compressor suction line and
a suitable pump. See News bulletin «Lubricants
lling in instr
Compressors».
el canalsobechecked a fewminutes
foss POE oil 160SZ from
uctions for Danfoss Commercial
FRCC. PC.007.B8.02
43
Application guidelines
Packaging
Ordering information and packaging
Single pack
Compressor models
SH09047037059660
SH10547037059666
SH12047037059666
SH14047037059668
SH16147037059670
SH18447037059673
SH180470400698116
SH240470400698116
SH295470400698119
SH300510465780161
SH380510465780167
SH4857706009001
Length
(mm)
Width
(mm)
Height
(mm)
Gross
weight
(kg)
83
Industrial pack
Compressor modelsNbr*
SH090811509506804942
SH105811509507505442
SH120811509507505442
SH140811509507505662
SH161811509507505822
4811509507506062
SH18
SH180611509657686852
SH240611509657686832
SH295611509657687022
SH300411509657686472
SH380411509658006712
Length
(mm)
Width
(mm)
Height
(mm)
Gross
weight
(kg)
stacking
Static
pallets
44
SH485411509658007372
* nbr: numberof compressor s per pack
FRCC. PC.007.B8.02
Application guidelines
Ordering information and packaging
Ordering information
Single pack
Danfoss SH scroll compressors can be ordered in
either industrial packs or in single packs. Please
use the code numbers from below tables for
ordering.
Compressors SH180 to 485 with rigid mounting
spacers are de
dicated for parallel mounting. For
useinsingleapplicationstherigid spacersmust
be replaced by exible grommets which are
available as accessory kit 8156138, see section
8156019Sight glass with gaskets (black & white)All modelsMultipack4
8156129Gasket for oil sight glass, 1"1/8 (white te on)All modelsMultipack10
7956005Gasket for oil sight g
8154001Danfoss Commercial Compressors blue spray paintAll modelsSingle pack1
lass, 1"1/8 (white te on)All modelsMultipack50
50
FRCC. PC.007.B8.02
Danfoss Commercial Compressorsisaworldwidemanufacturerof compressorsand condensing
units forrefrigerationand HVAC applications. Withawiderangeof high quality and innovative
productswehelp yourcompany to n
d thebest possibleenergy e cientsolutionthatrespects
theenvironmentand reducestotal lifecyclecosts.
Wehave 40 yearsof experiencewithinthe development of hermetic compressors which has
brought us amongst the
global leaders in our business, and positioned us as distinct variable
speed technology specialists. Today we operate from engineering and manufacturing facilities
spread across three continents.
Danfoss Variable Speed scroll
compressors
Maneurop® Variable Speed
reciprocating compressor s
Maneurop®Reciprocating
Compressors
Our products can be found in a v
Danfoss Air Conditioningscroll
compressors
TM
Optyma
& Optyma PlusTM
Condensing Units
Danfoss Heat Pump scroll
compressors
DanfossRefrigerationscroll
compressors
Lightcommercial reciprocatingcompressors
(manufactured by Secop)
ariety of applications such as rooftops, chillers, residential air
conditioners, heatpumps, coldrooms, supermarkets, milk tank cooling and industrial cooling processes.
Danfosscanacceptnoresponsibility for possibleerrorsincatalogues, brochuresand other printed material. Danfossreservestherighttoalterits productswithoutnotice.
Thisalsoappliesto productsalready onor
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