Danfoss VZH028 User manual

Instructions
Danfoss inverter compressors
VZH028-VZH065
© Danfoss | DCS (CC) | 2021.03 8510280P01AA - AN233086441027en-000501 | 1
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0
10
20
30
40
50
60
5
15
25
35
45
55
65
75
70
Condensing temperature (°C)
VZH028-044 operating map - R410A (SH 6 K)
-40 -30 -20 -10 0 10 20-35 -25 -15 -5 5 15 25 30 35
Evaporating temperature (°C)
900-6000 rpm
1200-6000 rpm
1800-6000 rpm
2400-6000 rpm
3600-6000 rpm 2400-6000 rpm
Voltage: 400-460V/208-230V
0
10
20
30
40
50
60
5
15
25
35
45
55
65
75
70
Condensing temperature (°C)
VZH052-065 operating map - R410A (SH 6 K)
-30 -20 -10 0 10 20-35 -25 -15 -5 5 15 25 30 35 40
Evaporating temperature (°C)
1000-6600rpm
1800-6600rpm
2400-6000rpm
4200-6000rpm
A: Model number
B: Serial Number
C: Refrigerant
D: Manufacturing year
E: Supply voltage range
F: Max operating current
G: Lubricant type and nominal charge
Installation and servicing of the compressor by qualified personnel only. Follow these instructions and sound refrigeration engineering
practice relating to installation, commissioning, maintenance and service.
The compressor must only be
used for its designed purpose(s)
and within its scope of application
(refer to «operating limits»). Consult
Application guidelines and datasheet
available from cc.danfoss.com
Never operate
compressor
without terminal
box cover in place
and secured.
Under all circumstances,
the EN378 (or other applicable
local safety regulation)
requirements must be fulfilled.
Wear protective goggles and
work gloves.
The compressor must
be handled with
caution in the vertical
position (maximum
offset from the
vertical : 15°).
The compressor is delivered under
nitrogen gas pressure (between
0.3 and 0.4 bar / 4 and 6 psi). Do
not disassemble bolts, plugs,
fittings, etc... unless all pressure
has been relieved from the
compressor.
A
B
C
D
E
F
G
Operating limits
Quick connect
spade terminals
VZH028-044
push
push
push
Electrical connections
All the above limits, temperatures and speeds, are secured by parameters in the drive and
application controller softwares.
VZH028 - VZH065 compressors can be
powered by the dedicated variable speed
drive or third party drive.
When Danfoss drive is selected, check carefully
for compatibility between compressor model
and variable speed drive.
Compressor
model
Driver
power
Driver
model
VZH028-J/G 6kW CDS803
VZH035-J/G 7.5kW CDS803
VZH044-J/G 10kW CDS803
VZH028-H 7.5kW CDS303
VZH035-H 11kW CDS303
VZH044-H 11kW CDS303
VZH052-J 11kW CDS303
VZH065-J 11kW CDS303
VZH052-G 11kW CDS303
VZH065-G 15kW CDS303
VZH052-H 15kW CDS303
VZH065-H 22kW CDS303
Note : These instructions replace instructions
in grommet kit.
VZH028-044 VZH052-065
Ring connect screw terminals
C & Q terminal box type
VZH052-065
VZH67F Map
Solid line bondaries:
SH=6K
Dash line bondaries:
need ensure Tdis
<135°C

Instructions
2 | AN233086441027en-000501 - 8510280P01AA © Danfoss | DCS (CC) | 2021.03
1 – Introduction
These instructions pertain to the VZH028-
VZH065 variable scroll compressors used for air-
conditioning and reversible heat pump systems in
residential applications. They provide necessary
information regarding safety and proper usage of
this product.
2 – Handling and storage
• Handle the compressor with care. Use the
dedicated handles in the packaging. Use the
compressor lifting lug and use appropriate and
safe lifting equipment.
• Store and transport the compressor in an
upright position.
• Store the compressor between -35°C and 55°C
/ -31°F and 131°F.
• Don’t expose the compressor and the
packaging to rain or corrosive atmosphere.
3 – Safety measures before assembly
Never use the compressor in a flammable
atmosphere.
• The compressor ambient temperature may not
exceed 50°C during off-cycle.
• Mount the compressor on a horizontal flat
surface with less than 7° slope.
• When installing a compressor model VZH,
use equipment specifically reserved for HFC
refrigerants, which was never used for CFC or
HCFC refrigerants.
• Use clean and dehydrated refrigeration-grade
copper tubes and silver alloy brazing material.
• Use clean and dehydrated system components.
• The piping connected to the compressor
must be flexible in 3 dimensions to dampen
vibrations.
• The compressor must always be mounted
using the rubber grommets supplied with the
compressor.
4 – Assembly
• Slowly release the nitrogen holding charge
through discharge and suction ports.
• Connect the compressor to the system as soon
as possible to avoid oil contamination from
ambient moisture.
• Avoid material entering into the system while
cutting tubes. Never drill holes where burrs
cannot be removed.
• Braze with great care using state-of-the-art
Basic connections
- Depending on the frequency converter
version, the physical position of individual
connectors may differ from below diagram.
- Always make sure that the compressor
terminals T1, T2, T3 are connected to the
frequency converter terminals 96, 97, 98
respectively.
- The compressor motor cable must be shielded
and the armoured part must be connected to
ground on both cable ends; at the side of the
compressor and at the side of the frequency
converter.
- Use an EMC cable gland for cable installation and
perfect grounding; The metallic terminal box of
the compressor has a paint-free surface around
the connection hole for better conductivity.
- A low pressure safety switch is mandatory
to avoid compressor vacuum operation.
- At start-up, verify that the compressor rotates
in the right direction and pumps.
Oil level switch assembly
Install the screw-in optical part on oil level switch
port. (Factory preset for manifold version VZH
compressor.)
Install the electrical part on optical part. Make
sure the cable outlet downside vertically.
* For LC-PR, make sure the cable outlet downside
or upside vertically.
L1
L2
L3
N
External
Load / Relay
LC-XN
12
3
230VAC
24VAC
0VAC
12
3
24VAC
External
Load / Relay
LC-XN
24VDC
0VDC
12
3
24VDC
External
Load / Relay
LC-XN
L / 24V
N / 0V
14
23
External
Load
LC-PR
LC-XN LC-PR
3
1
4
2
1: Power supply wire
2: Power supply wire
3: Output wire
4: Not used
31
4
2
1: Power supply (L or 24V)
2: Output NO CONTACT
3: Power supply (N or 0V)
4: Output COMMON
Electrical connections / Wiring for Oil level sensor
See at the correct diagram corresponding to different power supply models for proper wiring

Instructions
8510280P01AA - AN233086441027en-000501 | 3
© Danfoss | DCS (CC) | 2021.03
technique and vent piping with nitrogen gas
flow.
• Connect the required safety and control
devices.
5 – Leak detection
Never pressurize the circuit with oxygen or dry
air. This could cause fire or explosion.
• Do not use leak detection dye.
• Perform a leak detection test on the complete
system.
• The test pressure must not exceed:
Maximum compressor test
pressure (Low side)
30 bar for
VZH028-044
33.3 bar for
VZH052-065
Maximum compressor test
pressure (High side) 41.1 bar
Maximum pressure difference
between high side and low side
of the compressor
36 bar
• When a leak is discovered, repair the leak and
repeat the leak detection.
6 – Vacuum dehydration
• Never use the compressor to evacuate the
system.
•
Connect a vacuum pump to both the LP & HP sides.
• Pull down the system under a vacuum of 500
µm Hg (0.67 mbar) / 0.02 inch Hg absolute.
• Do not use a mega ohmmeter nor apply power
to the compressor while it is under vacuum as
this may cause internal damage.
7 – Electrical connections
• Switch off and isolate the main power supply.
• Before touching any potentially live part of the
drive, wait at least 4 minutes.
• The compressor is protected against excess
current by the frequency converter. Follow
local regulations regarding power line
protection.The compressor must be connected
to ground.
• Use 6.3 mm tabs for quick connect spade
terminals.
• Use a self-tapping screw to connect the ground
conductor to the compressor.
• Care must be taken during installation to
ensure that the compressor operates in the
correct direction. T1 (U), T2 (V) and T3 (W)
terminals of compressor and drive U, V, W must
match. Please refer to drawings for typical
wiring connections and examine the specific
wiring diagram located in the frequency
converter package. For further details, refer to
the application guidelines.
• Mounting: The base frame of the frequency
converter must be very well fixed to the
support to ensure a very good continuity
between the ground potential of all electrical
panels and electrical boxes of the system.
• Wiring: All control wires have to be of a
screeened design. The cable for electrical
motor supply has to be of a shielded design as
well. Correct earthing of the shield cover has to
be done using the method shown on drawings,
every time this one has to be earthed on each
end of the cables. Distinct cable trays must be
used for control and motor supply.
• The frequency converter ensures direct motor
protection and the factory set parameters
are such to protect the motor over all current
malfunctions.
An external overload is not necessary.
• Set the frequency converter parameters in
accordance with Danfoss recommendations
for the CDS frequency converter and VZH
variable speed compressor.
• Refer to variable speed drive manual for
electrical connections details and installation.
• Compressor motor protection is provided by
the variable speed drive.
8 – Filling the system
• Keep the compressor switched off.
• Fill the refrigerant in liquid phase into the
outlet of the condenser or the liquid receiver.
The charge must be as closed as possible
to the nominal system charge to avoid low
pressure operation and excessive superheat.
For VZH028-044, the refrigerant charge limit is
3.6 kg, For VZH052-065, the refrigerant charge
limit is 5.4 kg. Above this limit; protect the
compressor against liquid flood-back with a
pump-down cycle not lower than 1.18 bar (g)
for VZH028-044/1.8 bar (g) for VZH052-065 or a
suction line accumulator.
• Never leave the filling cylinder connected to
the circuit.
9 – Verification before commissioning
Use safety devices such as safety pressure
switch and mechanical relief valve in compliance
with both generally and locally applicable
regulations and safety standards. Ensure that
they are operational and properly set.
Check that the settings of high-pressure
switches do not exceed the maximum service
pressure of any system component.
•
A low-pressure switch is mandatory to avoid
vacuum operation. Minimum setting 1.0 bar (g)
for VZH028-044. Minimum pressure 1.5 bar for
VZH052-065.
• Verify that all electrical connections are
properly fastened and in compliance with local
regulations.
• When using discharge temperature sensor,
ensure that the discharge temperature sensor
is correctly installed and fitted to the discharge
piping (6 inches from discharge fitting) and
well connected, especially after maintenance
operations.
• After comissioning it is strongly recommended to
keep the frequency converter always energized.
10 – Start-up
• Never start the compressor when no refrigerant
is charged.
• Do not provide any power to the drive unless
suction and discharge service valves on
compressor are open, if installed.
• Energize the drive. The compressor must start,
according to defined ramp-up settings. If
the compressor does not start, check wiring
conformity.
• Check the frequency converter control panel:
If any alarm is displayed check the wiring and
in particular the polarity of the control cables.
If an alarm is shown, refer to the frequency
converter application manual. Verify in
particular the combination of compressor,
frequency converter and refrigerant.
• Check current draw and voltage levels on the
mains. The values for the compressor electrical
motor can be directly displayed on the
frequency converter control panel.
• The optimum compressor suction superheat is
around 6K. The maximum allowed superheat is
30K.
• Eventual reverse rotation can be detected by
following phenomena; the excessive noise,
no pressure differential between suction
and discharge, and line warming rather than
immediate cooling. A service technician should
be present at initial start-up to verify that
wiring from drive to compressor is properly
phased and that the compressor is rotating in
the correct direction.
• Note that a 300 seconds period is necessary
between 2 starts, a shorter period will be not
allowed by the drive. The minimum running
time is 12s for each start.
11 – Check with running compressor
Check current draw and voltage. Measurement
of amps and volts during running conditions must
be taken at other points in the power supply, not
in the compressor electrical box.
• Check suction superheat to reduce risk of
slugging.
• Observe the oil level at start and during
operation to confirm that the oil level remains
visible. Excess foaming in oil sight glass
indicates refrigerant on the sump.
• Monitor the oil sight glass for 1 hour after
system equilibrium to ensure proper oil return
to the compressor. This oil check has to be
done over the speed range to guarantee:
- a good oil return at low speed with minimum
gas velocity.
- a good oil management at high speed with
maximum oil carry over.
• Respect the operating limits.
• Check all tubes for abnormal vibration.
Movements in excess of 1.5 mm / 0.06 inch
require corrective measures such as tube
brackets.
• When needed, additional refrigerant in liquid
phase may be added in the low-pressure side
as far as possible from the compressor. The
compressor must be operating during this
process.
• Do not overcharge the system.
• Never release refrigerant to atmosphere.
• Before leaving the installation site, carry out
a general installation inspection regarding
cleanliness, noise and leak detection.
• Record type and amount of refrigerant charge
as well as operating conditions as a reference
for future inspections.
• Compressor failure to build up pressure: Check
all bypass valves in the system to ensure that
none of these has been opened. Also check
that all solenoid valves are in their proper
position.
• Abnormal running noise: Ensure the absence
of any liquid flood-back to the compressor by
means of measuring the return gas superheat
and compressor sump temperature. The sump
should be at least 6K above the saturated
suction temperature under steady-state
operating conditions.
• The high-pressure switch trips out: Check
condenser operations (condenser cleanliness,
fan operation, water flow and water

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