Danfoss BOCK FK20 User manual

AQ451838788471en-000201
BOCK®FK 2 0
Operating guide
FK20/120 N FK20/145 N FK20/170 N
FK20/120 K FK20/145 K FK20/170 K
FK20/120 TK FK20/145 TK FK20/170 TK
FKX20/120 N FKX20/145 N FKX20/170 N
FKX20/120 K FKX20/145 K FKX20/170 K
FKX20/120 TK FKX20/145 TK FKX20/170 TK
Translation of the original instructions

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About these instructions
Read these instructions before assembly and before using the compressor. This will avoid
misunderstandings and prevent damage. Improper assembly and use of the compressor can lead to
serious or fatal injury.
Observe the safety instructions contained in these instructions.
These instructions must be passed onto the end customer along with the unit in which the
compressor is installed.
The safety advice, which is contained in these instructions for assembly, and which is relevant for
regular operation and maintenance, must be forwarded by the manufacturer in his own documents
to the operator of the entire system. It must also be ensured, that personnel working in daily
operation with the compressor have access to important information such as safety and warning
advice about the compressor. Such persons must read the safety advice and have understood it.
Bock assumes no liability for any damage arising from non-compliance.

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Contents Page
1 Safety 4
  1.1 Identicationofsafetyinstructions
  1.2 Qualicationsrequiredofpersonnel
1.3 Danger to life and limb in the event of faults during operation
1.4 General safety instructions
1.5 Intended use
2 Product description 6
2.1 Brief description
2.2 Name plate
2.3 Type key
3 Areas of application 8
3.1 Refrigerants
3.2 Oil charge
3.3 Limits of application
4Compressor assembly 9
4.1 Setting up
4.2 Maximum permissible inclination
4.3 V-belt drive
4.4 Main bearing load
4.5 Electromagnetic clutch assembly
4.6 Pipe connections
4.7 Pipes
4.8 Operating the shut-off valves
4.9 Operating mode of the lockable service connections
  4.10Suctionpipelter
5 Commissioning 13
5.1 Preparations for start-up
5.2 Pressure strength test
5.3 Leak test
5.4 Evacuation
5.5 Refrigerant charge
5.6 Shaft seal
5.6.1 Notes on replacing the shaft seal
  5.7 Avoidingliquidshocks
6 Maintenance 16
6.1 Preparation
6.2 Work to be carried out
6.3 Recommended spare parts/accessories
6.4 Lubricants / Oils
6.5 Decommissioning
6.6 Valve plate, TK version
7 Accessories 18
7.1 Thermal protection thermostat
8 Technical Data 19
9 Dimensions and Connections 20
10 Declaration of incorporation 22

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1.1 Identicationofsafetyinstructions:
DANGER! Indicates a dangerous situation which, if not avoided, will cause
immediate fatal or serious injury.
WARNING!
Indicates a dangerous situation which, if not avoided,
may cause fatal or serious injury.
CAUTION!
Indicates a dangerous situation which, if not
avoided, may cause fairly severe or minor injury.
ATTENTION! Indicates a situation which, if not
avoided, may cause property damage.
INFO! Important information or tips on simplifying work.
1|Safety
1.2 Qualicationsrequiredofpersonnel
WARNING! Inadequatelyqualiedpersonnelposestheriskofaccidents,
 theconsequencebeingseriousorfatalinjury.Workon
compressors is therefore reserved for personnel with the
 qualicationslistedbelow:
• For example, a refrigeration technician, refrigeration mechatronic
engineer.
As well as professions with comparable training, which enables
personnel to assemble, install, maintain and repair refrigeration and
air-conditioning systems. Personnel must be capable of assessing
the work to be carried out and recognising any potential dangers.

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1|Safety
These assembly instructions describe the standard version of the FK20 manufactured by Bock. The
compressor is intended for use in refrigeration systems in compliance with the limits of application.
Onlytherefrigerantspeciedintheseinstructionsmaybeused.
Any other use of the compressor is prohibited!
The Bock refrigerating compressor named in the title is intended for installation in a machine (with-
in the EU according to the EU Directives 2006/42/EC Machinery Directive, 2014/68/EU Pressure
EquipmentDirective).
Commissioning is permissible only if the compressor has been installed in accordance with these as-
sembly instructions and the entire system into which it is integrated has been inspected and approved
in accordance with legal regulations.
1.5 Intended use
1.4 General safety instructions
1.3 Danger to life and limb in the event of faults during operation
WARNING! If a compressor continues to be operated during extreme running
noise and/or a sharp reduction in refrigerating capacity, there is
the danger of further events occurring, such as the fracture
of the housing wall. If people are standing in the immediate
surroundings, there is the risk of severe injury or even death from
 yingparts.
• In the event of extreme running noise, switch the compressor off
immediately.
• If there is a sharp reduction in refrigerating capacity, switch the
compressor off immediately.
• Secure the compressor against being switched on again.
• In such cases do not continue to operate the compressor under
any circumstances.
DANGER! • Refrigerating compressors are pressurised machines and as
such call for heightened caution and care in handling.
The maximum permissible overpressure must not be exceeded,
even for testing purposes.
WARNING! • Risk of burns! Depending on the operating conditions,
surface temperatures of over 60 °C on the discharge side or
below 0 °C on the suction side can be reached.

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2|Product description
Three different designs are available for various ranges of application:
> for air-conditioning the K Design
> for air-conditioning or normal cooling the N Design
> for deep freezing the TK Design
The differences lie mainly in the valve plate tooling which is adapted to each applica-
tion range where operational safety and efficiency are concerned.
Compact two-cylinder compressor in single row.
Three capacity ranges.
Lightweight aluminum design.
Lubricating oil pump with oil pressure relief valve independent of rotational direction.
Variable connection and fixing options.
Fig. 1
2.1 Brief description
Fig. 2
Suction shut-off
valve
Cylinder cover
Name plate
Shaft end
Shaft seal
Valve plate
Oil pump
Dimension and connection values can be found in Chapter 9
Discharge
shut-off valve
Sight glass

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2|Product description
/
FK 02 170 NX
1 Type designation
2 Displacement at 1450 rpm
3 LP: Max. permissible operating pressure
  (g)Lowpressureside
HP:
Max. permissible operating pressure
  (g)Highpressureside
4 Machine number
5 Factory-lledoiltype
Fig. 3
2.2 Name plate(example)
2.3 Type key(example)
¹)K - specially for air-conditioning
N - specially for air-conditioning or normal cooling
TK - specially for deep freezing
²)X- Esteroilcharging(HFCrefrigerant,e.g.R134a,R407C)
Designs ¹)
Swept volume
Size
Ester oil charging ²)
Series
1
2
3
4
5
BB12345A020
19/28bar
Observe the limits of application
diagrams!
}
FKX20/170N
14,8
Bock GmbH, Benzstr. 7
72636 Frickenhausen, Germany
BOCK
Öl: BOCK lub E55

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Max.permissibleoperatingpressure(g)high-pressureside(HP):
28 bar
3|Areas of application
ATTENTION! Compressor operation is possible within the operating limits.
These can be found in Bock compressor selection tool (VAP)
under vap.bock.de. Observe the information given there.
    -Max.permissibledischargeendtemperature:140°C
    -Permissibleambienttemperature:(-20°C)-(+100°C)
    -Max.permissibleswitchingfrequency:12x/h
    -Aminimumrunningtimeof2min.atequilibrium(continuous
operation) must be achieved.
Avoid continuous operation near the threshold. Should the
compressor happen to be used near the thresholds, we
recommend the use of a thermal protection thermostat
(Accessories, Chap. 7).
When operating in the vacuum range, there is a danger of air
entering on the suction side. This can cause chemical reactions,
a pressure rise in the condenser and an elevated compressed-
gas temperature. Prevent the ingress of air at all costs!
 Thecompressorsarefactory-lledwiththefollowingoiltype:
- for R134a, R404A/R507, R407C BOCK lub E55
- for R22 BOCK lub A46
Compressors with ester oil charge (BOCK lub E55)aremarkedwithanXinthetypedesignation(e.g.
FKX20/170N).
3.1 Refrigerants
• HFKW / HFC: R134a, R404A/R507, R407C
• HFCKW / HCFC: R22
3.2 Oil charge
3.3 Limits of application
INFO! For recharging, we recommend the above oil types. See chapter 6.4.

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4|Compressor assembly
4.1 Setting up
4.2 Maximum permissible inclination
Amax. 30°,
max. 2 minutes
amax. 15°,
continuous
operation
ATTENTION! Poor lubrication can damage the compressor.
Respect the stated values.
INFO! New compressors are factory-lled with inert gas. Leave this
service charge in the compressor for as long as possible and prevent
the ingress of air.
Check the compressor for transport damage before starting any
work.
Fig. 4
AA
aa
AA
aa
Storageat(-40°C)-(+100°C),maximumpermissiblerelativeHumidity10%-95%,no
condensation
 Fittings(e.g.pipeholders,additionalunitsetc.)onthecompressorarepermissibleonly
following consultation with Bock.
 Setuponanevensurfaceorframewithsufcientload-bearingcapacity.Thecompressorcan
be fastened as follows:
- using the 4 drill holes on the baseplate
- using the 3 side M10 tapped blind holes on the left or right of the compressor housing
- using the 4 M10 tapped blind holes on the front of the compressor housing.
Correct setup of the compressor and mounting of the belt drive are decisive for running
comfort, operating safety and the service life of the compressor.

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4|Compressor assembly
4.3 V-belt drive
4.4 Main bearing load
4.5 Electromagnetic clutch assembly
ATTENTION! Inappropriately designed belt drives, especially belt knocking
(offsets, inclinations) or excessive tensioning forces can cause
compressor damage! Make sure that the drive belt is designed
correctly, e.g. by using
 tensionersandselectingthebeltproleandthebeltlength.
The following description applies for an electromagnetic clutch secured to a shaft.
Toabsorbthemagneticeldoftheelectromagneticclutch,theslidingringlidhas
asnugtØ38h8(seeFig.6).
Toconnectthemagneticeld,removethemarkedAllenheadscrewsoftheslidingringlid
(seeFig.7).
Slidethemagneticeldtoasnug-tandfastenusingthethreeM5x20cheesehead
screwsprovided(Fig.7).Screwtorque=9Nm.
Further assembly of the electromagnetic clutch according to the clutch manufacturer.
Fig. 6
Sliding ring lid
Magneticeld
Fig. 7
To prevent the belt drive overloading the compressor main bearing,
ensure that:
Theengagementforceappliedbythebelttension(seeFig.5)
must not exceed Fmax per.=600N.
If the force engagement point shifts to the right (see Fig. 5,
smallpoint),theforceFmax per. reduces as per the following
formula:
Fmax per.= 30 kNmm
(50mm+L1[mm])
Fmax= 600 N
Mbmax= 30kNmm
L
1
(mm)
Fig. 5
Snugt

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4|Compressor assembly
4.7 Pipes
Pipes and system components must be clean and dry inside and free of scale, swarf and layers
of rust and phosphate. Only use air-tight parts.
Lay pipes correctly. Suitable vibration compensators must be provided to prevent pipes being
cracked and broken by severe vibrations.
Ensure a proper oil return.
Keep pressure losses to an absolute minimum.
4.6 Pipe connections
Valve spindle seal
4.8 Operating the shut-off valves
Before opening or closing the shut-off valve, release the valve spindle seal by approx. ¼ of a turn
counter-clockwise.
After activating the shut-off valve, re-tighten the adjustable valve spindle seal clockwise.
Fig. 9 Fig. 10
ATTENTION! Overheating can damage the valve.
Solder only using inert gas to inhibit oxidation products.
Release
Tighten
The pipe connections, if installed, have graduated inside diameters so
that pipes in the common millimeter and inch dimensions can be used.
The connection diameters of the shut-off valves are designed for
maximum compressor output. Therequiredpipecross-sectionmust
be matched to the capacity. The same applies for non-return
valves.
Fig. 8: Stepped
internal diameters

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4|Compressor assembly
4.9 Operating mode of the lockable service connections
Openingtheshut-offvalve:
a) Spindle1:turntotheleft(counter-clockwise)asfarasitwillgo.
—> Shut-off valve fully opened /
service connection 2 closed Fig. 11
Fig. 12
1
1
3
3
Pipe connection
Pipe connection
Openingtheserviceconnection(2):
b) Spindle1:Turn½-1rotationtotheright.
—> Service connection 2 opened / shut-off valve opened.
Connection 3 is provided for safety devices and is not lockable.
3
3
2
2
Afteractivatingthespindle,generallytthespindleprotectioncapagainandtightenwith14-16Nm.
This serves as a second sealing feature during operation.
For systems with long pipes and higher degree of contamination, a lter on the suction-side is
recommended.Thelterhastobebereneweddependingonthedegreeofcontamination(reduced
pressureloss).
4.10Suctionpipelter

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5|Commissioning
5.1 Preparations for start-up
5.4 Evacuation
First evacuate the system and then includethe compressor in the evacuation process.
Relieve the compressor pressure.
Open the suction and discharge line valves.
Evacuate the suction and discharge pressure sides using the vacuum pump.
At the end of the evacuation process, the vacuum should be < 1.5 mbar when the pump is switched off.
 Repeattheprocessasoftenasisrequired.
INFO! To protect the compressor against inadmissible operating conditions,
high-pressure and low-pressure pressostats are mandatory on the
installation side.
The compressor has undergone trials in the factory and all functions have been tested. There are
therefore no special running-in instructions.
Check the compressor for transport damage!
DANGER! Risk of bursting!
The compressor must only be pressurised using dried nitrogen (N2).
Never pressurise with oxygen or other gases!
The maximum permissible overpressure of the compressor must not
be exceeded at any time during the testing process (see name plate
data)! Do not mix any refrigerant with the nitrogen as this could
cause the ignition limit to shift into the critical range.
5.3 Leak test
Carry out the leak test on the refrigerating plant in accordance with EN 378-2 or a corresponding
safety standard, while always observing the maximum permissible overpressure for the compressor.
5.2 Pressure strength test
The compressor has been tested in the factory for pressure integrity. If however the entire system is
to be subjected to a pressure integrity test, this should be carried out in accordance with EN 378-2
or a corresponding safety standard without the inclusion of the compressor.

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5|Commissioning
CAUTION! Wear personal protective clothing such as goggles and protective
gloves!
Make sure that the suction and discharge line valves are open.
 Withthecompressorswitchedoff,addtheliquidrefrigerantdirectlytothecondenserorreceiver,
breaking the vacuum.
If the refrigerant needs topping up after starting the compressor, it can be topped up in vapour
formonthesuctionside,or,takingsuitableprecautions,alsoinliquidformattheinlettothe
evaporator.
ATTENTION! Avoidoverllingthesystemwithrefrigerant!
To avoid shifts in concentration, zeotropic refrigerant blends
(e.g. R407C) must always be added to the refrigerating plant
    inliquidform.
 Donotpourliquidrefrigerantthroughthesuctionlinevalveon
the compressor.
It is not permissible to mix additives with the oil and
refrigerant.
5.5 Refrigerant charge
5.6 Shaft seal
ATTENTION! Failure to observe the following instructions can cause loss
of refrigerant and damage to the shaft seal!
INFO! The shaft seal seals and lubricates with oil. An oil leakage
of 0.05 ml per operating hour is therefore normal. This applies
particularly during the run-in phase (200 – 300 h).
The compressor shaft is sealed to outside using a shaft seal. The sealing element rotates with
the shaft.
The following is especially important to ensuring fault-free operation:
The complete refrigerant circuit must be correctly executed and clean inside.
Heavy shocks and vibrations to the shaft as well as continuous cyclic operation are to be
avoided.
 Thesealingsurfacescansticktogetherduringprolongeddowntimes(e.g.winter).Therefore,run
the system every 4 weeks for 10 minutes.

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5|Commissioning
5.7 Avoidingliquidshocks
Topreventliquidshocks:
The complete refrigeration plant must be correctly designed and executed.
The capacities of all components must be compatible (particularly evaporator
andexpansionvalve).
Suction gas superheating at the evaporator output should be at least 7 –10 K (check setting
 oftheexpansionvalve).
 Thesystemmustreachastateofequilibrium.
 Particularlyincriticalsystems(e.g.severalevaporatorpoints),suitablemeasures,e.g.
 useofliquidtraps,solenoidvalveintheliquidline,etc.arerecommended.
Since changing the shaft seal involves encroaching into the refrigerant circuit, this is only recom-
mended, if the seal is losing refrigerant, or if oil is escaping in excess of the permissible amount (see
informationonpage14,chapter5.6,"Shaftseal").Changingtheshaftsealisdescribedintherelevant
spare part kit.
The shaft seal is a wearing part, and its service life depends on the prevailing conditions.
Damaging effects on the shaft seal:
• Too little suction gas superheat, particularly during wet operation
• Too high or too low belt tension
•Thermaloverload(operationoutsidethelimitsofapplication)
•Frequentcycling
• Long periods of stoppage
• Material deposits / dirt from the system
Due to these effects, the shaft seal can develop leaks, and it must then be replaced.
5.6.1 Notes on replacing the shaft seal
ATTENTION! Slugging can damage the compressor and cause refrigerant to
leak.

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6.1 Preparation
6.2 Work to be carried out
6|Maintenance
Oilchange:Inprinciple,anoilchangeisnotamandatoryrequirement,iftheequipmentiscorrectly
manufactured and properly operated. Based on decades of experience, we recommend however that
the following oil change/service work is carried out:
• Initialoilchangeduringtherstmaintenanceofthevehicle(atthelatestafteroneyear)
• Thenafterevery5,000operatinghours,atthelatesthoweverafter3years.Alsocleantheoillter.
• An oil change is also necessary, if the oil is very cloudy and dark, or after repairs have been carried
out on the compressor.
Emptyingtheshaftsealoilreservoir:Asrequireddependingonuse,butatthelatestafter1year
or approx. 1,400 operating hours
Where requirements are higher during use (frequent operation at the limits of application, or
inhotlandswithover+40°Cambienttemperature,orinthecaseofdeepfreezing), the following
requirementsmustbeobserved:
• Initialoilchangeduringtherstmaintenanceofthevehicle(atthelatestafteroneyear)
• Then an oil change after every 2,000 operating hours, at the latest however after two years. Also
 cleantheoillter.
Preventive maintenance
Theaboverequirementsforhigheruseapplicationsalsoapplyinthecaseofpreventivemaintenance.
The shaft seal must also be changed after 3 years.
Regularinspections(atleastannually):Checks to be carried out on oil level in the oil sight glass,
oilllleveloftheshaftsealintheoildrainhose,absenceofleaksinthecompressor,runningnoise,
vibrations, pressures, temperatures, and functioning of auxiliary devices such as the capacity control.
WARNING! Beforestartinganyworkonthecompressor:
Switch off the compressor and secure it to prevent a restart.
Relieve compressor of system pressure.
Preventairfrominltratingthesystem!
  Aftermaintenancehasbeenperformed:
Connect safety switch.
Evacuate compressor.
Release switch lock.

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6|Maintenance
6.4 Lubricants / Oils
Theoiltypelledasstandardinthefactoryismarkedonthenameplate,andthisshouldalwaysbe
used,eveninthecaseofmaintenanceunits.Alternativeoiltypescanvarysignicantlyinqualitydue
to additives or inferior raw materials by the manufacturer. Validation within the compressors entire
operating limits can not be guaranteed, if such alternative oil types are used. It is for this reason, that
we only recommend the use of oil from Bock! Bock assumes no liability for any damage arising from
alternative oil types.
Refrigerants Bock standard oil types
HFC
(e.g.R134a,R407,R404A)
BOCK lub E55
HCFC(e.g.R22) BOCK lub A46
6.3 Recommended spare parts/accessories
Maintenance set for oil change
• BOCK lub E55 1 l
• Oil drain screw with seal
Maintenance set for shaft seal
• shaft seal kit
• BOCK lub E55 1 l
• Oil drain screw with seal
Available spare parts and accessories can be found on our compressor selection tool under
vap.bock.de as well as in our online spare parts catalogue at bockshop.bock.de.
Only use original Bock spare parts!
6.5 Decommissioning
Close the shut-off valve on the compressor. Drain the refrigerant (it must not be discharged directly
into the environment) and dispose of it according to the regulations. When the compressor is
depressurised, undo the fastening screws of the shut-off valves. Remove the compressor using an
appropriate hoist. Dispose of the oil inside in accordance with the valid national regulations.

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6|Maintenance
Aspecialintermediateange,locatedbelowthedischargelinevalve,isusedtoattachthesensor
element(Partno.097B04175*).Wirethethermalprotectionthermostatinserieswiththecontrolline.
Technical Data:
Switching voltage max. : 24 V DC
Switching current max. : 2.5 A at 24 V DC
Switch-off temperature : 145 °C ± 5 K
Switch-on temperature : approx. 115 °C
7.1 Thermal protection thermostat (Item No. 097B07595*)
6.6 Valve plate, TK version
Based on the tried-and-tested N valve plate system, a valve plate with reduced dead space
hasbeenadaptedtotheFK20TKspecicallyforapplicationsinthedeep-freezearea.Thesystemis
equippedwithanon-interchangesafeguardtoavoidconfusingitwithNvalveplate.
Fig. 13
Non-interchangesafeguardfortheFK20valveplate,TKversion:
7|Accessories
* Please note that the legacy BOCK code numbers are without 097B

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8|Technical data
Type
No. of cylinders
Displace-
ment
cm3
Swept
volume
(1450 rpm)
m3/h
Weight
kg
Discharge
line
DV
mm / inch
Suction
line
SV
mm / inch
Oil
charge
Ltr.
Inertia
moment
of the
driving
unti
[kgm2]
Lubrication Oil pump
FK20/120
2
118 10,3 15,0
16 / 5/816 / 5/80,7 0,0013 Forced
lubrication
Independent
of rotational
direction
FK20/145 143 12,4 14,0 FK20/170 170 14,8 14,0
Connections
The technical data for the different designs K, N and TK are identical. The compressor type data therefore do not mention these additions.

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9|Dimensions and connections
Dimensions in ()=KDesign
=Centreofgravity
Shaft end
Dimensions in mm
Dimensions in mm
Fig. 14
Fig. 15
A1A
View X
155
7878
50
30
99 ±1
30°
130
135
125
X
110 h8
beidseitig
both sides
BSV
DV A2
F,G
K
X
4x 11
114,5
+2
215
271 (281) +2
150
H
3x M10x26
B1
B
4x M10x26
15573
60
265 +2
58,1
24,7
21,69
1,5
M8x25
49
135
6xM5
A4x6,5 DIN6888
1:4
36,3
34,3
25
60
38 -0,05
55,1
110 h8
0x26