Danfoss BOCK HGZ7 Semi Hermetic Compressor Installation Guide

June 13, 2024
Danfoss

Danfoss BOCK HGZ7 Semi Hermetic Compressor

Product Information

The BOCK B7o26ck36GFmribcHke compressor is a refrigerating compressor manufactured by Bock. It is designed for installation in a machine and is compliant with the EU Directives 2006/42/EC Machinery Directive and 2014/68/EU Pressure Equipment Directive. The compressor is intended for use in refrigeration systems within the specified limits of application.

Compatible Refrigerants

  • R404A/R507
  • R410A
  • R448A/R449A
  • R22

Intended Use

The compressor should only be used in refrigeration systems and must be installed in accordance with the provided assembly instructions.
The entire system, including the compressor, should be inspected and approved in accordance with legal regulations before commissioning.

Important Safety Instructions

  • DANGER: Indicates a dangerous situation that can cause immediate fatal or serious injury.
  • WARNING: Indicates a dangerous situation that can cause fatal or serious injury.
  • CAUTION: Indicates a dangerous situation that can cause fairly severe or minor injury.
  • ATTENTION: Indicates a situation that can cause property damage.
  • INFO: Provides important information or tips on simplifying work.

Qualifications Required

Work on compressors should only be performed by personnel who are qualified to work on pressurized refrigerant systems.
This includes engineers and professionals with comparable training who are capable of assessing the work and recognizing potential dangers.

Product Usage Instructions

  1. Before assembly and use, read the provided instructions carefully to avoid misunderstandings and prevent damage.
  2. Ensure that the compressor is not used in potentially explosive environments.
  3. The compressor should only be used in refrigeration systems within the specified limits of application.
  4. Use only the refrigerant specified in the instructions. Using any other refrigerant is prohibited.
  5. Follow the provided assembly instructions to install the compressor in a machine.
  6. Before commissioning, ensure that the entire system, including the compressor, has been inspected and approved according to legal regulations.
  7. Take extra caution when handling refrigerating compressors as they are pressurized machines. Avoid exceeding the maximum permissible overpressure, even for testing purposes.
  8. Regularly maintain and repair the refrigeration and air-conditioning systems as required by qualified personnel.
  9. Pass these instructions on to the end customer along with the unit in which the compressor is installed.

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 result in 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.

Safety

Identification 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.

Qualifications required of personnel

  • WARNING Inadequately qualified personnel poses the risk of accidents, the consequence being serious or fatal injury. Work on compressors is therefore reserved for personnel which is qualified to work on pressurized refrigerant systems:
  • 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.

General safety instructions

  • WARNING Risk of accidents.
  • 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.
  • 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.
  • Avoid contact with refrigerant necessarily.
  • Contact with refrigerant can cause severe burns and skin damage.

Intended use

WARNING The compressor may not be used in potentially explosive environments!

  • These assembly instructions describe the standard version of the compressor named in the title manufactured by Bock. Bock refrigerating compressors are intended for installation in a machine (within 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.
  • The compressors are intended for use in refrigeration systems in compliance with the limits of application.
  • Only the refrigerant specified in these instructions may be used.

Any other use of the compressor is prohibited!

Product description

Short description standard version

  • Semi-hermetic, two-stage, six cylinder reciprocating compressor with suction-gascooled drive motor.
  • Stages divided into LP / HP at the ratio of 2 : 1
  • Compressor with intermediate pressure shut-off mounted and insulated.Danfoss-BOCK-HGZ7-Semi-Hermetic-Compressor-FIG-1

Short description optional version, enclosed

  • Liquid subcooler, expansion valve, solenoid valve, filter drier and a sight glass enclosed separately, for individual, external mounting (Fig. 3).

Short description optional version, mounted

  • Liquid subcooler, expansion valve, solenoid valve, filter drier and a sight glass mounted directly to the compressor, piped and insulated (Fig. 4).

Name plate (example)

Type key (example)

Areas of application

Refrigerants

  • HFKW :
  • (H)FCKW: R404A/R507, R410A, R448A/R449A R22

Oil charge

  • The compressors are filled at the factory with the following oil type: – für R404A/R507, R410A, R448A/R449A BOCK lub E55 – für R22 BOCK lub A46
  • Compressors with ester oil charge (BOCK lub E55) are marked with an X in the type designation (e.g. HGZX7/2110-4 R404A).

INFO

  • For refilling, we recommend the above oil types. Alternatives: see Chapter 8.5.
  • ATTENTION The oil level must be in the visible part of the sight glass; damage to the compressor is possible if overfilled or underfilled!

Limits 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.
  • Permissible ambient temperature (-20°C) – (+60°C)
  • Max. permissible discharge end temperature 140 °C
  • Max. permissible switching frequency 12x /h.
  • A minimum running time of 3 min. steady-state condition (continuous operation) must be achieved.

For operation with supplementary cooling:

  • Use only oils with high thermal stability.
  • Avoid continuous operation near the threshold.
  • 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!
  • ATTENTION Any operation with frequency converter is inadmissible.

Areas of application

  • Max. permissible operating pressure (LP/MP/HP)1): 19/19/28 bar
    • LP = low pressure MP = intermediate pressure HP = high pressureDanfoss-BOCK-HGZ7-Semi-Hermetic-Compressor-FIG-8
  • tO Evaporation temperature (°C)
  • tC Condensing temperature (°C)
  • tOh suction gas superheat (K)
  • Design for other areas on request
  • Max. permissible operating pressure (LP/MP/HP)1): 19/19/28 bar
  • LP = low pressure MP = intermediate pressure HP = high pressure

Subcooling temperature

  • The design of the expansion valve on the compressor can be defined with the help of the diagram by approximately calculating the subcooling temperature arising in the relevant operating conditions (t0/tc).
  • Diagrams for determining the subcooling temperature at the output of the liquid subcooler.Danfoss-BOCK-HGZ7-Semi-Hermetic-Compressor-FIG-9
  • Subcooling temperature at the subcooler outlet (FUA)
  • Evaporating temperatureDanfoss-BOCK-HGZ7-Semi-Hermetic-Compressor-FIG-10
  • The subcooling temperature at the sub-cooler outlet (FUA)
  • Evaporating temperature

Description of functions

  • The refrigerant suctioned out of the evaporator (20) is compressed by the 4 cylinders of the LP stage (2) to intermediate pressure MP. After that, the superheated refrigerant flows through the intermediate pressure chamber (3), where it is cooled by the liquid sub cooler system to reduce the discharge end temperature. The refrigerant then flows through the intermediate pressure line (4) to the electric motor of the compressor to cool the motor. After this, the refrigerant is suctioned in by the two HP cylinders (5) and compressed to the final pressure.

Liquid sub cooler system

  • The liquid sub cooler system consists of the components
  • liquid sub cooler (plate heat exchanger) (6)
  • the expansion valve (7)
  • sight glass (8)
  • solenoid valve (9)
  • filter drier (10)
  • After the refrigerant reciever (15), the liquid line will be split into two lines:
  • Line A leads through the liquid subcooled (6) and the subcooled refrigerant flows to the evaporator (20). Through Line, B refrigerant is expanded through the expansion valve (7) into the liquid subcooled (6) in order to subcool the refrigerant of Line A and through the intermediate pressure line (MP) to cool the superheated refrigerant, which is compressed from low pressure to intermediate pressure chamber (3).

Two-stage refrigeration cycle with liquid sub-coolerDanfoss-BOCK-HGZ7
-Semi-Hermetic-Compressor-FIG-11

Explanations

  1. Compressor
  2. Cylinder LP-stage
  3. Intermediate pressure chamber MP
  4. Intermediate pressure line MP
  5. Cylinder HP-stage
  6. Liquid subcooler
  7. Reinjection valve
  8. Sight glass
  9. Solenoid valve
  10. Filter drier
  11. Damper, pressure line
  12. Oil separator
  13. Non-return valve
  14. Condenser
  15. Refrigerant receiver
  16. Filter drier
  17. Solenoid valve
  18. Sight glass
  19. Expansion valve (evaporator) 20 Evaporator
  20. Liquid separator
  21. Damper, suction line
  22. Filter suction line
  • LP = Low pressure
    • MP = Intermediate pressure
  • HP = High pressure
    • FUE = Liquid sub-cooler, inlet
  • FUA = Liquid sub-cooler, outlet

Compressor assembly

INFO New compressors are factory-filled 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.

Storage and transportation

  • Storage at (-30°C) – (+70°C), maximum permissible relative humidity 10% -95 %, no condensation.
  • Do not store in a corrosive, dusty, vaporous atmosphere or in a combustible environment.
  • Use transport eyelet.
  • Do not lift manually!
  • Use lifting gear!

Setting up

  • ATTENTION Fittings (e.g. pipe holders, additional units, mounting parts, etc.) on the compressor are not permissible!
  • Provide adequate clearance for maintenance work.
  • Ensure adequate compressor ventilation.
  • Do not use it in a corrosive, dusty, damp atmosphere or a combustible environment.
  • Setup on an even surface or frame with sufficient load-bearing capacity.
  • The compressor in principle rigidly install.

Installation of the liquid subcooled system (optional version)

Separately enclosed components:

  1. Liquid sub-cooler
  2. Reinjection valve
  3. Solenoid valve
  4. Filter drier
  5. Sight glass
  6. Screw-in sleeve, solder adapter, and seals
  7. Please check for completeness of parts before beginning installation.

INFO

Observe the manufacturer‘s instructions!
ATTENTION To avoid vibration cracks in the subcooled system, the individual components must be mounted directly to the compressor or installed as a decoupled unit!

Assembly:

INFO The points listed here represent general guidelines and information on how to pipe and connect the sub-cooler unit. To perform this work technical knowledge and skill as well as proof of a hard-soldering test certificate in accordance with DIN EN 13133 is required.

Pipe connections:
For connections, see the dimension diagram in Chapter 10.

  • System design, piping, and necessary support points for the individual components must be carefully planned and carried out.
  • Properly insulate the liquid sub cooler against condensation and heating and the related loss of performance.
  • For rigidity reasons, the use of stainless steel pipes with a wall of 1 mm is preferred. The pipes must be free of tension during and after soldering to prevent possible breaks later on.

INFO

  • Use only suitable hard solder and flux. Solder under an inert gas atmosphere when copper components are to be soldered! The accompanying expansion valve is designed and adjusted for the compressor and the listed refrigerant (sensor charge, nozzle). Only use expansion valves approved and supplied by Bock!
  • The intermediate pressure line and intermediate pressure chamber are fully insulated at the factory. To mount the expansion valve, cut the insulation as shown in the marked area in Fig. 22, page 18. Correct sensor placement is marked by an unpainted area on the pipe.Danfoss-BOCK-HGZ7-Semi-Hermetic-Compressor-FIG-15
R Connection of pressure compensation line for expansion valve 7/16″ UNF
W Refrigerant injection connection M22 x 1,5
X Schrader connection for intermedie-pressure gauge 7/16″ UNF
Y Position of temperature sensor / unpainted

Installation example, liquid sub-cooler with accessoriesDanfoss-BOCK-HGZ7
-Semi-Hermetic-Compressor-FIG-16

  1. Liquid sub-cooler
  2. Filter drier
  3. Solenoid valve
  4. Sight glass
  5. Expansion valve
  6. Temp.
  7. sensor expansion valve
  8. Pressure compensation connection
  • FUA Liquid sub-cooler Outlet
    • FUE Liquid sub-cooler, Inlet

INFO General notes:

  • Sensor lines, wires, etc. should not be attached with cable binders directly to pipes or frames; otherwise, the thin pipes may be worn through. It is better to run them through spiral protective tubes.
  • If the compressor will be set up outside, UV-resistant materials should be used.

Factory-installed liquid subcooler system (optional design)

  • Liquid subcooler, expansion valve, solenoid valve and the sight glass are mounted directly at the compressor, piped and insulated.Danfoss-BOCK-HGZ7-Semi-Hermetic-Compressor-FIG-17
  • FUE: Liquid sub-cooler inlet
  • FUA: Liquid sub-cooler outlet

Pipe connections

  • ATTENTION Damage is possible.
  • Superheating can damage the valve.
  • Remove the pipe supports therefore from the valve for soldering. Only solder using inert gas to inhibit oxidation products (scale)
  • The pipe connections have graduated inside diameters so that pipes with standard millimeter and inch dimensions can be used.
  • The connection diameters of the shut-off valves are rated for maximum compressor output. The actual required pipe cross-section must be matched to the output. The same applies to non-return valves.

INFO

  • A soldering support for a tube diameter of 54 mm is mounted to the suction shut-off valve of the compressor.
  • A soldering support for a tube diameter of 2 1/8” accompanies the compressor.

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 from being cracked and broken by severe vibrations.
  • Ensure a proper oil return.
  • Keep pressure losses to an absolute minimum.

Laying suction and pressure lines

  • ATTENTION Improperly installed pipes can cause cracks and tears, the result being a loss of refrigerant.
  • INFO Proper layout of the suction and discharge lines directly after the compressor is integral to the system’s smooth running and vibration behavior.
  • A rule of thumb: Always lay the first pipe section starting from the shut-off valve downwards and parallel to the drive shaft.Danfoss-BOCK-HGZ7-Semi-Hermetic-Compressor-FIG-19

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.Danfoss-BOCK-HGZ7-Semi-Hermetic-Compressor-FIG-20

The operating mode of the lockable service connections

Opening the shut-off valve:

  • Spindle: turn to the left (counter-clockwise) as far as it will go.
  • The shut-off valve completely opened / service connection was closed. The connection which cannot be shut off is intended for safety devices.

Opening the service connection

  • Spindle: Turn ½ – 1 turn to the right clockwise.
  • Service connection opened / shut-off valve opened.
  • The connection which cannot be shut off is intended for safety devices.
  • After activating the spindle, generally fit the spindle protection cap again and tighten with 14-16 Nm.
  • This serves as a second sealing feature during operation.

Electrical connection

DANGER

  • Risk of electric shock! High voltage!
  • Only carry out work when the electrical system is disconnected from the power supply!
  • ATTENTION When attaching accessories with an electrical cable, a minimum bending radius of 3 x the cable diameter must be maintained for laying the cable.

INFO

  • Connect the compressor motor in accordance with the circuit diagram (see inside of terminal box).
  • Use suitable cable entry point of the correct protection type (see name plate) for routing cables into the terminal box. Insert the strain reliefs and prevent chafe marks on the cables.
  • Compare the voltage and frequency values with the data for the mains power supply.
  • Only connect the motor if these values are the same.

Information for contactor and motor contactor selection

  • All protection devices and switching or monitoring units must be fitted in accordance with the local safety regulations and established specifications (e.g. VDE) as well as with the manufacturer’s infor-mation. Motor protection switches are required! Motor contactors, feed lines, fuses and motor protection switches must be rated on the basis of the maximum working current (see name plate). For motor protection use a current-dependent and time-delayed overload protection device for moni-toring all three phases. Set the overload protection device so that it must be actuated within 2 hours, if there is 1.2 times the max. working current.

Circuit diagram for part-winding start

QA1 Main switch
FC1.1 Motor protection switch part winding 1
FC1.2 Motor protection switch part winding 2
FC2 Fuse control current circuit
BP2 High pressure safety monitor
BP3 Safety chain (high/low pressure monitoring)
BP1 Oil differential pressure monitor
SF1 Control voltage switch
BT3 Release switch (thermostat)
QA2 Mains contactor part winding 1
QA3 Mains contactor part winding 2

Danfoss-BOCK-HGZ7-Semi-Hermetic-Compressor-FIG-24

KF1 Delay relay max. 1 s (slow release), part winding 2
KF2 Delay relay max. 20 s (slow release),
Open solenoid Y1 (subcooled)
KF3 Delay relay max. 20 s (slow release),
compressor switch-off (suction sub-cooler)
QM1 Solenoid valve intermediate cooler
EC1 Compressor motor
BT1 Cold conductor (PTC sensor)
BT2 Thermal protection thermostat (PTC sensor)
K1 Auxiliary contactor safety chain

Standard motor, designed for direct or partial winding start

  • Compressors with this marking are suitable for direct or partial winding start. The motor winding is subdivided into two parts:
  • Part winding 1 = 50% and part winding 2 = 50%.
    • This winding division reduces the start-up current needed for a part winding start to approx. 50% of that for a direct start.

INFO

  • A mechanical unloaded start with bypass solenoid valve is not required.
  • The motor is wired for direct start (YY) at the factory. For part winding start Y/YY the bridges must be removed and the motor feed line connected according to the circuit diagram:
  • ATTENTION Failure to do this results in opposed rotary fields and results in damage to the motor. After the motor starts up via partial winding 1, partial winding 2 must be switched on after a maximum delay of one second . Failure to comply can adversely affect the service life of the motor.

Electronic trigger unit MP10

  • The compressor motor is fitted with cold conductor temperature sensors (PTC) connected to the electronic trigger unit MP 10 in the terminal box. Readiness to operate is signalled by the H3 LED (green) after the power supply is applied. In the case of excess temperature in the motor winding, the unit switches off the compressor and the H1 LED lights red.
  • The hot gas side of the compressor can also be protected against overtemperature using a thermal protection thermostat (accessory). The H2 LED (red) is provided for the protection function.
  • The unit trips when an overload or inadmissible operating conditions occur. Find and remedy the cause.

INFO

  • The unit has a restart prevention device. After you have rectified the fault, interrupt the mains voltage. This unlocks the restart prevention device and the LEDs H1 and H2 go out.

Connection of the trigger unit MP10

  • INFO Connect the trigger unit MP10 in accordance with the circuit diagram. Protect the trigger unit with a delayed-action fuse (F) of max. 4 A. In order to guarantee the protection function, install the trigger unit as the first element in the control power circuit.

Temperature monitoring connections:

  • Motor winding: Terminals 1 – 2
  • Thermal protection thermostat: Terminals 3 – 4
  • Restart prevention: Terminals 5 – 6

ATTENTION

  • Terminals 1 – 6 on the trigger unit MP 10 and terminals PTC 1 and PTC 2 on the compressor terminal board must not come into contact with mains voltage.
  • This would destroy the trigger unit and PTC sensors.
  • The supply voltage at L1-N (+/- for DC 24 V version) must be identical to the voltage at terminals 11, 12, 14 and 43.

Function test of the trigger unit MP10

  • Before start-up, troubleshooting or making changes to the control power circuit, check the functionality of the trigger unit:
Pos Procedure LED H1 LED H2 LED H3
red red green
1 Interrupt power supply (L1 or S1) OFF OFF OFF

• Release the motor temperature sensor connection (1 or 2)
• Release the hot gas temperature sensor (if installed) (3 or 4)
2| • Restore the power supply (L1 or S1)|

ON

|

ON

| ON
• Function check of motor temperature sensor: operational
• Function check of hot gas temperature sensor: operational
3| • Interrupt power supply again (L1 or S1)| OFF| OFF| OFF
• Reconnect terminals 1 or 2 and/or 3 or 4
4| • Restore the power supply (L1 or S1):| OFF| OFF| ON
• MP10 is operational again

The compressor and the trigger unit MP10 are operational when the H3 LED (green) lights.

Oil sump heater (accessories)

  • When the compressor is at a standstill, refrigerant diffuses into the lubricating oil of the compressor’s housing, depending on pressure and ambient temperature. This reduces the lubricating capacity of the oil. When the compressor starts up, the refrigerant contained in the oil evaporates out through the reduction in pressure. The consequences can be foaming and migration of the oil, causing oil shocks under certain circumstances.
  • Operation: The oil sump heater operates when the compressor is at a standstill. When the compressor starts up, the oil sump heater switches off again automatically.
  • Connection: The oil sump heater must be connected via an auxiliary contact (or parallel wired auxiliary contact) of the compressor contactor to a seperate electric circuit.
  • El. data: 230 V – 1 – 50/60 Hz, 140 WDanfoss-BOCK-HGZ7-Semi-Hermetic-Compressor-FIG-28
  • ATTENTION The oil sump heater must not be connected to the electrical circuit of the safety control chain.

Commissioning

Preparations for start-up

  • INFO In order to protect the compressor against inadmissible operating conditions, high pressure and low pressure pressostats are manda-tory 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!

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.

DANGER Risk of bursting!

  • The compressor must only be pressurised using 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.
  • 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.

Evacuation

  • ATTENTION Do not start the compressor if it is under vacuum. Do not apply any voltage – even for test purposes (must only be operated with refrigerant).
  • Under vacuum, the spark-over and creepage current distances of the terminal board connection bolts shorten; this can result in winding and terminal board damage.
  • First evacuate the system and then include the compressor in the evacuation process. Relieve the compressor pressure.
  • Open the suction and pressure line shut-off 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 this process as often as is required.
  • In addition to the suction or high pressure side, the intermediate pressure area of the compressor must also be evacuated (use connection X, see page 18, fig. 22). The solenoid valve of the subcooling system (page 19, fig. 23, item 3) must be opened.

Refrigerant charge

  • CAUTION Wear personal protective clothing such as goggles and protective gloves!
  • Make sure that the suction and pressure line shut-off valves are open.
  • With the compressor switched off, add the liquid refrigerant directly to the condenser or receiver, breaking the vacuum.
  • Pay attention to adequate refrigerant fill before starting up the compressor.
  • During operation, refrigerant must be free of bubbles in sight glasses 1 and 2 of the liquid subcooler.
  • 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 overfilling the system with refrigerant!
  • To avoid shifts in concentration, zeotropic refrigerant blends must always only be filled into the refrigerating plant in liquid form.
  • Do not pour liquid coolant through the suction line valve on the compressor.
  • It is not permissible to mix additives with the oil and refrigerant.

Start-up

  • WARNING Ensure that both shut-off valves are open before starting the compressor!
  • Check that the safety and protection devices (pressure switch, motor protection, electrical contact protection measures, etc.) are all functioning properly.
  • Switch on the compressor and allow to run for a minimum of 10 min.
  • Check the oil level by: The oil must be visible in the sightglass.
  • ATTENTION If larger quantities of oil have to be topped up, there is a risk of oil hammer effects.
  • If this is the case check the oil return!

Avoiding slugging

  • ATTENTION Slugging can damage the compressor and cause refrigerant to leak.

To prevent slugging:

  • The complete refrigeration system must be properly designed.
  • All components must be compatibly rated with each other with regard to output  (particularly the evaporator and expansion valves).
  • Suction gas superheat at the compressor input should be min. 7 – 10 K. (check the setting of the expansion valve).
  • The system must reach a state of equilibrium.
  • When selecting the evaporator expansion valve, pay attention to correction factors for liquid subcooling. Avoid transfer of refrigerant into the compressor when the system is at a standstill.
  • The use of a liquid separator is recommended.
  • ATTENTION To avoid liquid shocks on the HP stage, the expansion valve may only be opened approx. 15-20 seconds after the compressor is switched on (full load operation).

At compressor shut-down:

  • Close the solenoid valve approx. 15 – 20 seconds before the com-pressor is switched off.

Maintenance

Preparation
  • 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 infiltrating the system!
  • After maintenance has been performed:
  • Connect safety switch.
  • Evacuate compressor.
  • Release switch lock.

Work to be carried out

  • In order to guarantee optimum operational reliability and service life of the compressor, we recommend carrying out servicing and inspection work at regular intervals:

Oil change:

  • not mandatory for factory-produced series systems.
  • for field installations or when operating near the application limit: for the first time after 100 to 200 operating hours, then approx. every 3 years or 10,000 – 12,000 operating hours.
  • Dispose of used oil according to the regulations; observe national regulations.
  • Annual checks: Oil level, leak tightness, running noises, pressures, temperatures, function of auxiliary devices such as oil sump heater, and pressure switch.

Recommended spare parts/accessories

  • Available spare parts and accessories can be found on our compressor selection tool under vap.bock.de as well as at bockshop.bock.de. Only use genuine Bock spare parts!

Replacing the valve plates

  • The compressors are divided into an LP and an HP compressor stage. Different valve plate designs are required because of the different ducts in the individual compressor stages.
  • WARNING The valve plates have been fitted with safety bolts to prevent any confusion.
  • The safety bolts engage in the corresponding bores on the cylinder heads, the safety bolts must not be removed!Danfoss-BOCK-HGZ7-Semi-Hermetic-Compressor-FIG-29

Lubricants/oil

The oil type filled as standard in the factory is marked on the nameplate, and this should always be used, even in the case of maintenance units. Alternative oil types can vary significantly in quality due to additives or inferior raw materials by the manufacturer. Validation within the compressor’s 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
HFKW (e.g. R404A, R407C) BOCK lub E55
HFCKW (e.g. R22) BOCK lub A46

Decommissioning

  • Close the shut-off valves on the compressor. Drain the refrigerant (it must not be discharged into the environment) and dispose of it according to the regulations. When the compressor is depressurized, 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 applicable national regulations.

Technical data

Danfoss-BOCK-HGZ7-Semi-Hermetic-Compressor-
FIG-30

  • PW = Part Winding, motors for part winding starting 1 = 1. part winding, 2 = 2. part winding ¹) For solder connections ²) in standard design LP = Low-pressure stage HP = High-pressure stage Oil sump heater: 230V –
  1. 50/60 Hz 140 W Tolerance (± 10%) relative to the mean value of the voltage range.
  2. Take account of the max. operating current / max. power consumption for the design of fuses, supply lines, and safety devices.
  3. All specifications are based on the average of the voltage range
  4. 380-420 V Y/YY -3- 50 Hz PW, 440-480 V Y/YY -3- 60 Hz PW > Winding ratios: 50% / 50 %

Dimensions and connections

A compressor in standard design

  • Intermediate pressure mixed line mounted and insulated. (Liquid sub-cooler with accessories as an extra item) Danfoss-BOCK-HGZ7-Semi-Hermetic-Compressor-FIG-32

Compressor in optional design

  • (Liquid subcooler with accessories attached directly to the compressor)Danfoss-BOCK-HGZ7-Semi-Hermetic-Compressor-FIG-33

View X:

  • Connection possibility for oil level regulator
    • Three-hold connector for oil level regulator
  • Products ESK, AC+R, CARLY (3x M6, 10 deep)

SV DV| Suction line                    see technical data, Chapter 9 Discharge line|
---|---|---
FUE| Liquid subcooler IN| Ø 16 mm – 5/8″
FUA| Liquid subcooler OUT| Ø 16 mm – 5/8″
A| Connection suction side, not lockable| 1/8“ NPTF
A1| Connection suction side, lockable| 7/16“ UNF
A2| Connection intermediate pressure, not lockable| 1/8“ NPTF
A3| Connection intermediate pressure, not lockable| 1/4“ NPTF
B| Connection discharge side, not lockable| 1/8“ NPTF
B1| Connection discharge side, lockable| 7/16“ UNF
C| Connectoin oil pressure safety switch OIL| 7/16“ UNF
D| Connection oil pressure safety switch LP| 7/16“ UNF
D1| Connection oil return from oil separator| 1/4“ NPTF
E| Connection oil pressure gauge| 7/16“ UNF
F| Oil drain| M22 x 1,5
FS| Sight glass liquid line| Ø 12 mm
H| Oil charge plug| M22 x 1,5
J| Oil sump heater (accessories)| M22 x 1,5
K| Sight glass| –
L| Connection thermal protection thermostat| 1/8“ NPTF
L1| Thermal protection thermostat| 1/8“ NPTF
N| Filter drier| Ø 12 mm
O| Connection oil level regulator| see view X
ÖV| Connection oil service valve| 1/4“ NPTF
ÖV1| Oil service valve| 7/16“ UNF
P| Connection oil differential pressure sensor| M20 x 1,5
Q| Connection oil temperature sensor| 1/8“ NPTF
R| Connection of pressure compensation line for expansion valve| 7/16“ UNF
R1| Pressure compensation line for expansion valve| Ø 6 mm
T| Solenoid valve| Ø 12 mm
U| Expansion valve – refrigerant-dependent| Ø 12 mm
W| Connection refrigerant injection| M22 x 1,5
X| Connection for Schrader valve for intermediate pressure manometer| 7/16“ UNF

Declaration of incorporation

  • Declaration of incorporation for incomplete machinery in accordance with EC Machinery Directive 2006/42/EC, Annex II 1. B
  • Manufacturer: Bock GmbH
  • Benzstraße 7
  • 72636 Frickenhausen, Germany
  • We, as manufacturer, declare in sole responsibility that the incomplete machinery

Name: Semi-hermetic compressor

  • Types: HG(X)12P/60-4 S (HC) ……………………HG(X)88e/3235-4(S) (HC)

  • UL-HGX12P/60 S 0,7……………………… UL-HGX66e/2070 S 60

  • HGX12P/60 S 0,7 LG …………………….. HGX88e/3235 (ML/S) 95 LG

  • HG(X)22(P)(e)/125-4 A …………………… HG(X)34(P)(e)/380-4 (S) A

  • HGX34(P)(e)/255-2 (A) ………………….. HGX34(P)(e)/380-2 (A)(K)

  • HA(X)12P/60-4 ……………………………… HA(X)6/1410-4

  • HAX22e/125 LT 2 LG ……………………. HAX44e/665 LT 14 LG

  • HGX12e/20-4 (ML/S) CO2 (LT) ……….. HGX44e/565-4 S CO2

  • UL-HGX12e/20 (S/ML) 0,7 CO2 (LT)… UL-HGX44e/565 S 31 CO2

  • HGX12/20-4 (ML/S/SH) CO2T………….. HGX46/440-4 (ML/S/SH) CO2 T

  • UL-HGX12/20 ML(P) 2 CO2T…………. UL-HGX46/440 ML(P) 53 CO2T

  • HGZ(X)7/1620-4 ……………………………. HGZ(X)7/2110-4

  • HGZ(X)66e/1340 LT 22…………………… HGZ(X)66e/2070 LT 35

  • HRX40-2 CO2 T H………………………….. HRX60-2 CO2 T H

  • Name: Open type compressor

  • Types: F(X)2 …………………………………… F(X)88/3235 (NH3)

  • FK(X)1………………………………….. FK(X)3

  • FK(X)20/120 (K/N/TK)…………….. FK(X)50/980 (K/N/TK)

  • Serial number: BC00000A001 – BN99999Z999Danfoss-BOCK-HGZ7-Semi-Hermetic-Compressor-FIG-34

  • Declaration of incorporation of partly completed machinery in accordance with UK Statutory Instrument Supply of Machinery (Safety) Regulations 2008, Annex II 1. B

  • Manufacturer: Bock GmbH

  • Benzstraße 7

  • 72636 Frickenhausen, Germany

  • We, as manufacturer, declare in sole responsibility that the partly completed machinery

  • Name: Semi-hermetic compressor

  • Types: HG(X)12P/60-4 S (HC) ……………………HG(X)88e/3235-4(S) (HC)

  • UL-HGX12P/60 S 0,7……………………… UL-HGX66e/2070 S 60

  • HGX12P/60 S 0,7 LG …………………….. HGX88e/3235 (ML/S) 95 LG

  • HG(X)22(P)(e)/125-4 A …………………… HG(X)34(P)(e)/380-4 (S) A

  • HGX34(P)(e)/255-2 (A) ………………….. HGX34(P)(e)/380-2 (A)(K)

  • HA(X)22e/125-4 …………………………….. HA(X)6/1410-4

  • HAX22e/125 LT 2 LG ……………………. HAX44e/665 LT 14 LG

  • HGX12e/20-4 (ML/S) CO2 (LT) ……….. HGX44e/565-4 S CO2

  • UL-HGX12e/20 (S/ML) 0,7 CO2 (LT)… UL-HGX44e/565 S 31 CO2

  • HGX12/20-4 (ML/S/SH) CO2T………….. HGX46/440-4 (ML/S/SH) CO2 T

  • UL-HGX12/20 ML(P) 2 CO2T…………… UL-HGX46/440 ML(P) 53 CO2T

  • HGZ(X)7/1620-4 ……………………………. HGZ(X)7/2110-4

  • HGZ(X)66e/1340 LT 22…………………… HGZ(X)66e/2070 LT 35

  • HRX40-2 CO2 T H………………………….. HR(Z)X60-2 CO2 T (H)(V)

  • Name: Open type compressor

  • Types: F(X)2 …………………………………………… F(X)88/3235 (NH3)

  • FK(X)1………………………………………….. FK(X)3

  • FK(X)20/120 (K/N/TK)…………………….. FK(X)50/980 (K/N/TK)

  • Serial number: BC00000A001 – BN99999Z999Danfoss-BOCK-HGZ7-Semi-Hermetic-Compressor-FIG-35

  • PED – CLASSIFICATION (as per EU Pressure Equipment Directive 2014/68/EU)

  • DECLARATION OF CONFORMITY for use of the compressors within the European Union (as per EU Pressure Equipment Directive 2014/68/EU)

  • We hereby declare that piping of the refrigerant compressors

  • HGZX7/2110-4 R404A,

  • HGZX7/2110-4 R448A/R449A

  • HGZX7/2110-4 R410A

  • HGZ7/2110-4 R22 agrees with the Pressure Equipment Directive 2014/68/EU dated 15 May 2014.

  • Valid for Category I piping

  • Evaluation procedure module A

  • The other parts of the piping fall under article 3§3 of the

  • Guideline and correspond to good engineering practice

  • Frickenhausen, 2021-03-01 i.A. Alexander Layh,

  • Global Head of R&D

  • Danfoss A/S

  • Climate Solutions

  • danfoss.com

  • +45 7488 2222

  • Any information, including, but not limited to information on selection of product, its application or use, product design, weight, dimensions, capacity or any other technical data in product manuals,
    catalogues descriptions, advertisements, etc. and whether made available in writing, orally, electronically, online or via download, shall be considered informative, and is only binding if and to the
    extent, explicit reference is made in a quotation or order confirmation. Danfoss cannot accept any responsibility for possible errors in catalogues, brochures, videos and other material.

  • Danfoss reserves the right to alter its products without notice. This also applies to products ordered but not delivered provided that such alterations can be made without changes to form, fit or
    function of the product.

  • All trademarks in this material are property of Danfoss A/S or Danfoss group companies. Danfoss and the Danfoss logo are trademarks of Danfoss A/S. All rights reserved.

  • © Danfoss | Climate Solutions | 2023.07

Documents / Resources

| Danfoss BOCK HGZ7 Semi Hermetic Compressor [pdf] Installation Guide
BOCK HGZ7 Semi Hermetic Compressor, BOCK HGZ7, Semi Hermetic Compressor, Hermetic Compressor, Compressor
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References

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