Danfoss VZH052-065 Application guide

Application guidelines

Danfoss scroll compressors

VZH052-065

Single

R410A

http://cc.danfoss.com

Content

GENERAL INFORMATION ........................ 4

PRODUCT INFORMATION ....................... 5

Features......................................................5

How do IDVs work? ................................................... 5

Compressor model designation ..............6

Nomenclature ............................................................ 6

Technical specifications ............................7

Dimensions ..............................................10

VZH052-065G/J/H ...................................................10

Electrical data, connections and wiring 13

Supply voltage ......................................................... 13

Phase sequence and reverse rotation

protection .................................................................. 15

IP rating ....................................................................... 16

Motor protection.....................................................16

Approval and certificates .......................17

Low voltage directive 2014/35/EU .................... 17

Internal free volume............................................... 17

SYSTEM DESIGN ..................................... 18

Drive installation .....................................18

Direct and indirect exposure of drive to water
18

Condensation ...........................................................18

Dust Exposure .......................................................... 18

Mechanical Mounting ........................................... 18

Ambient temperature ........................................... 19

EMC installation ..................................... 20

EMC best practices ................................................. 20

EMC remediation ....................................................20

EMC remediation .................................................... 21

Mechanical dimension ......................................... 21

Unit Architecture .................................... 22

Design piping ......................................... 23

General requirements ...........................................23

Design compressor mounting .............. 24

General requirements ........................................... 24

Single requirements...............................................24

Manage oil in the circuit ........................ 25

Requirement ............................................................. 25

System evaluation ..................................................25

Test, criteria and solutions ................................... 25

Manage sound and vibration ................ 26

Compressor sound radiation ..............................26

Mechanical vibrations ........................................... 27

Gas pulsation ............................................................ 27

Manage superheat ................................. 28

Requirement ............................................................. 28

System evaluation ..................................................28

Test, criteria and solutions ................................... 29

Manage off cycle migration ................... 30

Requirement ............................................................. 30

System evaluation .................................................30

Manage operating envelope ................. 32

Requirement ............................................................. 32

System evaluation .................................................. 33

Manage speed limit .................................37

Speed limit requirement ...................................... 37

Start/Stop/Ramp setting ...................................... 37

Control logic ........................................... 38

Safety control logic requirements .................... 38

Short cycle protection ......................................... 39

Defrost cycle logic .................................................. 39

Pump-down logic recommendations .............39

Oil management logic ..........................................40

Reduce moisture in the system ..............41

Requirements ........................................................... 41

Solutions.....................................................................41

INTEGRATION INTO SYSTEMS .............. 42

Assembly line procedure ....................... 42

Compressor storage ...............................................42

Compressor holding charge ............................... 42

Handling .................................................................... 42

Piping assembly.......................................................43

System pressure test and leak detection ....... 43

Vacuum evacuation and moisture removal . 44

Refrigerant charging .............................................. 44

Dielectric strength and insulation resistance

tests .............................................................................. 44

Commissioning ....................................... 45

Preliminary check.................................................... 45

Initial start-up ........................................................... 45

System monitoring .................................................45

Oil level checking and top-up ............................ 45

Troubleshooting ..................................... 46

Dismantal and disposal ......................... 49

ORDERING INFORMATION ................... 50

Packaging ............................................... 50

Ordering codes ........................................51

Accessories ...............................................52

3AB237586440343en-000601

General Information

PRODUCT INFORMATIONSYSTEM DESIGNINTEGRATION INTO SYSTEMORDERING INFORMATION GENERAL INFORMATION

Danfoss scroll compressors are designed and
manufactured according to the state of the
art and to valid European and US regulations.
Particular emphasis has been placed on
safety and reliability. Related instructions are
highlighted with the following icons:

This icon indicates instructions to avoid
safety risk.

R

This icon indicates instructions to avoid
reliability risk.

The purpose of this guideline is to help
customers qualify compressors in the unit.
You are strongly advise to follow these
instructions. For any deviation from the
guidelines, please contact Danfoss Technical
Support. In any case, Danfoss accepts no
liability as a result of the improper integration
of the compressor into the unit by the system
manufacturer.

4 AB237586440343en-000601

Features

Intermediate discharge
valves for better efficiency
at low pressure-ratio

GENERAL INFORMATIONSYSTEM DESIGNINTEGRATION INTO SYSTEMORDERING INFORMATION PRODUCT INFORMATION

Optimized scrolls for
better part load efficiency

EMC (Electro-Magnetic
Compatibility) bracket
provided allows for
grounding termination
of shielded wire-harness,
which reduces EMC
emissions between drive
and compressor

New designed oil cup to
minimize oil stirring loss under
high liquid level

PVE 32 lubricant ensures better
lubrication and efficiency

High speed oil circulation
minimized by a oil return
tube

New distributed IPM
motor lead to higher
power factor

Linear control oil pump

How do IDVs work?

Danfoss Intermediate Discharge Valves (IDVs)
are located close to the discharge side of the
compressor. They reduce excessive compression
of refrigerant under part-load conditions while
maintaining the same cooling capacity. The IDVs
open when discharge pressure falls below the
built-in optimization point. They adapt the effort
of the motor to the varying load and pressure
conditions in the system, thus reducing the effort
of the motor and its electrical consumption
and improving the system’s seasonal energy
efficiency.

5AB237586440343en-000601

Compressor model designation

Nomenclature

Compressor nomenclature

BNAGC065ZHV

Variable speed

GENERAL INFORMATIONSYSTEM DESIGNINTEGRATION INTO SYSTEMORDERING INFORMATION PRODUCT INFORMATION

PVE 32 (160 HV) lubricant,

R410A refrigerant

Swept volume

Design pressure ratio

C: IDV and part load

ef iciency optimizedf

Frequency converter
nomenclature

Dedicated compressor

drive for VZH scroll

High overload

output power

P11K/P15K/P22K

Family

VZH scroll

Lubricant

in cm³/rev

Serie 303

in kW

Evolution index

Motor protection type
N: no internal motor protection

(protection by drive)

Equipement version
A: brazed connections, single version
D: brazed connections, unified version

Oil sight glass Oil level switch

Single version Threaded None
Unified version Threaded Threaded

Motor voltage code to CDS303 *
G: 380-480V/3~/50 & 60Hz
H: 525-600V/3~/50 & 60Hz
J: 200-240V/3~/50 & 60Hz

* main supply voltage to frequency converter

H2E20T4P11K303CDS

RFI class

H2/H3/HX

Enclosure protection

IP rating
E20/E55

Main supply voltage

T2: 200-240V/3 ph/50-60 Hz
T4: 380-480V/3 ph/50-60 Hz
T6: 525-600V/3ph/50-60 Hz

Note:
High overload output power: output power @160% Torque

6 AB237586440343en-000601

Technical specifications

Compressor size

Frequency converter
variants

Compressor and
frequency converter
combinations

To have the optimum compressor selection,
select a compressor size which achieves the
peak load system cooling capacity demand at its
maximum speed.

Different frequency converter variants are
available according to:

1. Mains supply voltage

2. IP class (CDS303 drives are available in IP20 or
IP55 housings)

When the compressor size and mains voltage
have been defined in the above selection criteria,
the code number tables from the “Ordering
information and packaging” section provides the
appropriate frequency converter sizes and up
to four corresponding code numbers for each
compressor model.

Detailed performances can be found in
datasheets and in selection programs.

3. RFI (Radio Frequency Interference) class H2/H3
or HX.

4. Printed Circuit Board (PCB) coated

Note this compressor is equipped with
a six-pole electrical motor so the applied
frequency from the inverter will be 50 Hz for
1000 rpm up to 330 Hz for 6600 rpm.

Please refer to the table below

min max

Compressor speed

Drive output frequency Hz 50 330

rps 16.7 110

rpm 1000 6600

GENERAL INFORMATIONPRODUCT INFORMATIONSYSTEM DESIGNINTEGRATION INTO SYSTEMORDERING INFORMATION

PRODUCT INFORMATION

7AB237586440343en-000601

Technical specifications

Compressor
specifications

Displacement

Compressor

model

VZH065 65.1 4.0 3.9 138 11.7 413 14.1 498 25.8 911 1.57 53 35 77
VZH052 52 .1 3.2 3.1 109 9.4 332 11.3 399 20.6 727 1.57 53 35 77

GENERAL INFORMATIONPRODUCT INFORMATIONSYSTEM DESIGNINTEGRATION INTO SYSTEMORDERING INFORMATION

Swept volume

(cm³/re v) (cu.in/rev) (m³/h) (cu.ft/h) (m³/h) (cu.ft/h) (m³/h) (cu.ft/h) (m³/h) (cu.ft/h) (dm

1000 rpm 3000 rpm 3600 rpm 6600 rpm

Oil charge Net weight

3

) (oz) (kg) (lbs)

Frequency converter
specifications

PRODUCT INFORMATION

T2: 200 - 240 V ±10% (3-phase)

Mains supply voltage

Supply frequency 50 / 60 Hz
Output voltage 0 - 100 % of supply voltage
Inputs 6 digital (0-24V), 2 analog (0/±10V or 4-20mA, scalable)
Programmable outputs 2 digital (0-24V), 1 analog (0/4-20mA), 2 relay
Protection functions Over-current protection, low / high current handling
Compressor functions Motor protection, compressor ramp up/down control

T4: 380 - 480 V ±10% (3-phase)
T6: 525 - 600V ±10% (3-phase)

8 AB237586440343en-000601

Technical specifications

OIL level sensor A TEKLAB LC-XN optical-electrical level sensor

is fixed on the inverter compressor. The oil level
sensor prism is fixed on the compressor, the
electrical part is ordered by accessory kit. The oil
level sensor monitors the compressor oil level
and sends oil level signal to an external relay or
digital input of unit controller. A 5±2 seconds
delay is recommended to mitigate oil level
fluctuationand avoid false alarms.

- Lack of oil: Circuit between 2 and 3 will be
opened internally, there will be no current
flowing through load or coil of external relay,
relay is open.

230VAC MODEL

L1
L2
L3

N

Sensor

External

Load / Relay

1

2

3

24VAC

0VAC

External

Load / Relay

- Enough oil: Circuit between 2 and 3 will be
closed internally, there will be current flowing
through load or coil of external relay, relay is
close.

Note: For 24VDC, output voltage in case of lack
of oil is >13V DC and not 0V

For customers who needs UL certificates, please
order 24V AC/DC sensor.

24VAC MODEL

1

2

Sensor Sensor

3

24VDC

24VDC MODEL

0VDC

1

GENERAL INFORMATIONPRODUCT INFORMATIONSYSTEM DESIGNINTEGRATION INTO SYSTEMORDERING INFORMATION

2

3

External

Load / Relay

PRODUCT INFORMATION

Oil level sensor is a special component which
assembles on variable speed compressor. It is
provided in oil level sensor accessory kit.

VZH052-065

9AB237586440343en-000601

Dimensions

ΦD

ΦD

VZH052-065G/J/H

GENERAL INFORMATIONPRODUCT INFORMATIONSYSTEM DESIGNINTEGRATION INTO SYSTEMORDERING INFORMATION

PRODUCT INFORMATION

H

H1

H2

H2

L1

L2

L1

H

H1

L2

Single version Unified version

Mounting GrommetTerminal box

29.5

EMC bracket to terminations
of shielded wire

Recommended torque for
mounting bolts: 11 Nm (±1 Nm)

Version Compressor model

Earth grounding

D H H1 H2 L1 L2

(mm) (inch) (mm) (inch) (mm) (inch) (mm) (inch) (mm) (inch) (mm) (inch)

Single VZH052-065 183.5 7. 22 436 17.17 403 15 .87 261 10.28 190 .5 7. 5 190. 5 7. 5 8590007

Unified VZH052-065 183. 5 7. 22 436 17.17 403 15.87 261 10. 28 190.5 7. 5 190.5 7. 5 8590013

Ø11

Ø 41

Outline drawing number

10 AB237586440343en-000601

Dimensions

Connection Details

Suction connection Br aze d 7/8 "
Discharge connection Brazed 3/4"
Oil sight glass Threaded (1"1/8 – 18 UNF)
Oil equalization connection ­Shrader Male 1/4" Flare incorporating a Schrader valve

1) VZH compressors single versions come
equipped with a threaded oil sight glass with
1"1/8 – 18 UNEF connection. It can be used for
a visual check of oil amount and condition.

Compressor models Brazed connection size

VZH052-065

Suction 7/8 " 1-1/4" 7/ 8"

Discharge 3/4" 1-1/4" 3/4" 120Z0 366

VZH compressors are all delivered with suction
and discharge brazed connections only. They are
copper-plated steel connections.

VZH052-065 single version

2) Schrader: The oil fill connection and
gauge port is a 1/4" male flare connector
incorporating a Schrader valve.

   

Rotolock adaptor set

(adaptor, gasket, sleeve, nut)

Rotolock Solder sleeve ODF Code Number Code Number

120Z0128



Rotolock adaptor

( adaptor only)

120Z0 367

GENERAL INFORMATIONPRODUCT INFORMATIONSYSTEM DESIGNINTEGRATION INTO SYSTEMORDERING INFORMATION

PRODUCT INFORMATION

Rotolock adaptors are available, refer to the
information above.

11AB237586440343en-000601

Dimensions

CDS303 Frequency
converter

Frequency converter dimensions depend
on supply voltage, IP rating and power. The
table below gives an overview of the overall
dimensions and different drive enclosures (B1 ­B4). Details for each drive enclosure are on the
following pages.

GENERAL INFORMATIONPRODUCT INFORMATIONSYSTEM DESIGNINTEGRATION INTO SYSTEMORDERING INFORMATION

W

IP20 IP55

Drive supply voltage

Compressor

voltage code

Drive power kW

PRODUCT INFORMATION

T2: 200-240/3/50-60 11 J VZH052-065 B4

11*

T4: 380-480/3/50-60

G

Compressor model

VZH052 B3

15 VZH065 B3

15

T6: 525-600/3/50-60

VZH052 B3

H

22 VZH065 B4

Variable speed compressor package VZH065 (voltage code G) + CDS303 (T4, 11kW) is qualified, to be used at drive supply voltage 380-440V (3 phase, 50/60Hz).
Any further information please contact local Danfoss engineers.

Overall drive size

[H x W x L]

mm

(inch)

Drive enclosure

520x230x242

(20.47x9.06x9.53)

399 x165x249

(15.71x6 .5x9. 8)

399 x165x249

(15.71x6 .5x9. 8)

399 x165x249

(15.71x6 .5x9. 8)

520x230x242

(20.47x9.06x9.53)

Overall drive size

[H x W x L] mm

(inch)

incl. decoupling

plate

595x230x242

(23.43x9.06x9.53)

420x165x249

(16.54x6.5x9.8)

420x165x249

(16.54x6.5x9.8)

420x165x249

(16.54x6.5x9.8)

595x230x242

(23.43x9.06x9.53)

Clearance

above/

below

mm

(inch)

200

(8)

100

(4)

100

(4)

100

(4)

200

(8)

Overall drive size

[H x W x L] mm

(inch)

Drive enclosure

650x242x260

B2

(25.59x9.53x10.24)

480x242x260

B1

(18.90x9.53x10.24)

480x242x260

B1

(18.90x9.53x10.24)

480x242x260

B1

(18.90x9.53x10.24)

650x242x260

B2

(25.59x9.53x10.24)

Min 100/200
Clearance above for cooling

L

H

Min 100/200
Clearance above for cooling

Overall drive

size

[H x W x L]

mm

(inch)

incl.

decoupling

plate

-

-

-

-

-

Clearance

above/

below

mm

(inch)

200

(8)

100

(4)

100

(4)

100

(4)

200

(8)

Enclosure Height Width Depth Mounting hole

Frame IP Class A A

1)

a B b C d e f

(mm) (inch) (mm) (inch) (mm) (inch) (mm) (inch) (mm) (inch) (mm) (inch) (mm) (inch) (mm) (inch) (mm) (inch) kg lb

B1 IP55 480 18.9 - - 454 17.87 242 9.53 210 8.27 260 10.24 19 0.75 9 0.35 9 0.35 23 51
B2 IP55 650 25.59 - - 624 24.57 242 9.53 210 8.27 260 10.24 19 0.75 9 0.35 9 0.35 27 60
B3 IP20 399 15.71 420 16.54 380 14.96 165 6.5 140 5. 51 249 9.80 12 0.47 6.8 0.27 7.9 0. 31 12 26
B4 IP20 520 20.47 595 23.43 495 19.49 230 9.06 200 7. 87 242 9.53 - - 8.5 0.33 15 0.59 23 51

1)

A

Including decoupling plate.

The dimensions are only for the physical units, but when installing in an application it is necessary to add space for free air passage both above and below the units.
The amount of space for free air passage is listed in “frequency converter dimensions - Clearance above/below (mm/inch)”.

12 AB237586440343en-000601

Max. Weight

Electrical data, connections and wiring

Supply voltage

Compressor electrical
specifications

RLA (Rated Load Amp)

MOC (Max Operating
Current)

Because VZH compressors are powered by a
frequency converter, the mains frequency, 50 or
60 Hz, is no longer an issue. Only the mains
voltage is to be taken into account. With 3 motor
voltage codes, the most common mains voltages
and frequencies are covered. Never connect the
VZH compressor directly to the mains power
supply in case of motor burnt.

Compressor rated

voltage (V)

400 VZH052-G
575 VZH052-H 22.6 26
400 VZH065-G 27. 2 31.2
575 VZH065-H 27. 2 31.2
208 VZH052-J
208 VZH065-J 55.3 63.6

RW: Winding resistance per winding, measured at motor terminals
RLA: Rated load Amp

Model

RW(Ω) at 20°C line

Rated Load Amp value is the current value at
maximum load, in the operating envelope, and at
maximum speed and rated drive input voltage.

Max operating current is the maximum
continuous current which is 115% of RLA. This

Voltage code Mains voltage range of drive

J 200-240V / 3ph / 50Hz & 60Hz (±10%)

G 380-480V / 3ph / 50Hz & 60Hz (±10%)

H 525-600V /3ph / 50Hz & 60Hz (±10%)

to line

0.177Ω±7 %

0.053Ω±7%

RLA (A)

22.6 26

44.2 50.7

Max Operating

Current (A)

RLA is the measured value at the compressor
terminals (after the drive).

value is printed on compressor nameplate.
MOC can be used to select cables and contactors.

GENERAL INFORMATIONPRODUCT INFORMATIONSYSTEM DESIGNINTEGRATION INTO SYSTEMORDERING INFORMATION

PRODUCT INFORMATION

Wiring connections

Electrical power is connected to the compressor
terminals by Ø 4.8mm (3/16") screws. The
maximum tightening torque is 3Nm. Use a 1/4"
ring terminal on the power leads.

Terminal cover mounting The terminal cover and gasket should be installed

prior to operation of the compressor. The terminal
cover has two outside tabs, 180 degrees apart,

Terminal cover removal

push

EMC bracket to terminations
of shielded wire

Earth grounding

that engage the terminal fence. When installing
the cover, check that it is not pinching the lead
wires.

push

push

13AB237586440343en-000601

Electrical data, connections and wiring

Fuses Danfoss recommends using the fuses listed

below to protect service personnel and property

For circuit breakers, Moeller types have been

tested and are recommended.
in case of component break-down in the
frequency converter.

Frequency

converter

GENERAL INFORMATIONPRODUCT INFORMATIONSYSTEM DESIGNINTEGRATION INTO SYSTEMORDERING INFORMATION

3x200-240V
CDS303-11k W 80A gG KTN-R80 JKS-80 JJN-80 5014006 -080 KLN-R80 NZMB1-A10 0 NZMB1- A100
3x380-480V
CDS303-11k W 63A gG KTS-R40 JKS-40 JJS-40 5014006-040 KLS-R40 PKZM4-50 PKZM4-63
CDS3 03-15kW 63A gG KTS-R50 JKS-50 JJS-50 5014006-050 KLS-R50 PKZM4-50 PKZM4- 63
3x525-600V
CDS3 03-15kW 63A gG KTS-R-45 JKS-45 JKJS-45 5014006-050 KLSR045 PKZM4-50 PKZM4-63
CDS303-22kW 63A gG KTS-R-60 JKS-60 JJS-60 5014006-063 KLSR060 NZM B1-A10 0 NZMB1-A10 0

EN50178 compliant fuses

Size Typ e Type RK1 Type J Typ e T Type RK1 Type RK1 Moeller type

Bussmann SIBA Little fuse IP20 IP55

UL Compliant fuses Recommended circuit breaker

Wire sizes Below table lists maximum wiring sizes for the motor compressor power supply cables.

PRODUCT INFORMATION

from network
to drive

I

Power input

Circuit breaker

From network to frequency converter From frequency converter to compressor

Typ e mm² AWG Type mm² AWG

200 - 240 V

380 - 400 V

525 - 600 V

Note: The wire size in the guideline is the maximum wire size that connectors can accept but not the actual needed cable. The need­ed cable size should be specified by the OEM depending on the unit design, ambient temperature, the wire material, current, etc...

CDS303-11k W 10 8 VZH052-J 10 8
CDS303-11k W 16 6 VZH065-J 16 6

CDS303-11k W 4 12 VZH052-G 4 12
CDS3 03-15kW 4 12 VZH065-G 6 10
CDS3 03-15kW 4 12 VZH052-H 4 12
CDS303-22kW 4 12 VZH065-H 6 10

from drive to
to compressor

14 AB237586440343en-000601

Electrical data, connections and wiring

Soft-start control

Phase sequence and reverse rotation protection

The CDS303 frequency converter generates by
design a compressor soft start with an default
initial ramp up of 7.5s to 50 rps.

Current inrush will not exceed the frequency
converter maximum current.

The compressor will only operate properly
in a single direction. If electrical connections
are done correctly between the drive and the
compressor terminals (compressor T1/T2/T3 and
drive terminals U, V & W matching), the drive will
provide correct phase supply to the compressor,
and reverse rotation will be not possible:

• CDS terminal U (96) to VZH terminal T1

• CDS terminal V (97) to VZH terminal T2

• CDS terminal W (98) to VZH terminal T3

If compressor T1/T2/T3 and drive U, V & W
terminals are not matching, the compressor

Basically seen from the mains, the inrush peak
reach a level which is only a few percent more
than the rated nominal current.

can operate in a reverse rotation. This results in
excessive noise, no pressure differential between
suction and discharge, and suction line warming
rather than immediate cooling. The compressor
can be rapidly damaged in these conditions.
If reverse rotation symptoms occur, shut the
compressor down and connect the phases to
their proper terminals.

Mains connection to the CDS frequency
converter order has no influence on the output
phase sequence which is managed by the
frequency converter.

GENERAL INFORMATIONPRODUCT INFORMATIONSYSTEM DESIGNINTEGRATION INTO SYSTEMORDERING INFORMATION

PRODUCT INFORMATION

15AB237586440343en-000601

Electrical data, connections and wiring

The compressor terminal box IP rating according to IEC529 is IP22.IP rating

GENERAL INFORMATIONPRODUCT INFORMATIONSYSTEM DESIGNINTEGRATION INTO SYSTEMORDERING INFORMATION

Element Numerals or letters Meaning for the protection of equipment

Against ingress of solid foreign objects

First characteristic

numeral

Second

characteristic

numeral

0
1
2
3
4
5
6

0
1
2
3
4
5
6
7
8

(non protected)
≥ 50 mm diameter
≥ 12.6 mm diameter
≥ 2.5 mm diameter
≥ 1.0 mm diameter
dust protected
dust tight

Agains ingress of water with harmful effects

(non protected
vertically dripping
dripping (15° tilted)
spaying
splashing
jetting
powerful jetting
temporary immersion
continuous immersion

Motor protection

PRODUCT INFORMATION

Voltage imbalance

VZH scroll compressors are not equipped with
an internal motor protector. Motor protection
is provided by the variable speed drive. All
parameters are factory preset in order to
guaranty locked rotor or overload current
protection.

The maximum allowable voltage imbalance
between each phase is 3%. Voltage imbalance
causes high amperage over one or several

When a warning situation is reached in the
current control, the CDS frequency converter
will automatically reduce the compressor
speed in order to keep the motor current of the
compressor below the maximum allowed.

phases, which in turn leads to overheating and
possible drive damage.

16 AB237586440343en-000601

Approval and certificates

certificates

VZH compressors comply with the following approvals and certificates.Approvals and

CE

(European Directive)
UL

(Underwriters Laboratories)

EMC Class A Group 1

2014/30/EU

CCC VZH code G

VZH code G & code J

All VZH models

VZH compressor and drive package

Low voltage directive 2014/35/EU

Internal free volume

Products VZH052-065

Declaration of conformity ref.
Low voltage directive 2014/35/EU

Products Internal free volume at LP side without oil (lite/cu.inch)

VZH052 4. 7/287

VZH065 4.7/287

GENERAL INFORMATIONPRODUCT INFORMATIONSYSTEM DESIGNINTEGRATION INTO SYSTEMORDERING INFORMATION

Contact Danfoss

PRODUCT INFORMATION

17AB237586440343en-000601

Drive installation

Direct and indirect exposure of drive to water

GENERAL INFORMATIONPRODUCT INFORMATIONINTEGRATION INTO SYSTEMORDERING INFORMATION SYSTEM DESIGN

Condensation

IP20 drives are intended for indoor or cabinet
mounting. Application example: drive fitted in
a machine room, basement or in an electrical
cabinet together with other electric / electronic
components such as the unit controller or
contactors.

Condensation must always be avoided. There is a
specific risk of condensation when the frequency
converter or some of its components are
colder than moist ambient air. In this situation,
the moisture in the air can condense on the
electronic components.

• Operating with the frequency converter
constantly connected to the mains can help
to reduce the risk of condensation. Install a
cabinet heater in situations where there is a
real possibility of condensation due to ambient
conditions.

• If the drive is IP 20, then evaluate and prevent
possibility of condensation above drive.
Example: condensation on metallic frame above
drive, piping… If unavoidable, solutions like

For outdoor use the electrical cabinet must be
IP54 or the drive itself must be IP54. Application
example: rooftop units or condensing units.

If IP54 with LCP make sure that the gasket is
applied to ensure tightness.

It is recommended to place drive at least 30cm
from ground to protect against floods.

cabinet heater, a pace heater, top hat on the
drive, insulation in the electric panel can be a
solution.

PCB temp

dew
point

• Water resulting of condensation must not
accumulate on the bottom of electric panel.
Provide a drain for condensed water to run out
if necessary.

• No other forced cooling then internal drive fan.

Dust Exposure

Mechanical Mounting
Clearance

Avoid Dust forms and deposits on the surface
of the drive and inside on circuit boards and the
electronic components. These deposits act as
insulation layers and hamper heat transfer to
the ambient air, reducing the cooling capacity.
The components become warmer. This causes
accelerated aging of the electronic components,
and the service life of the unit decreases. Dust
deposits on the heat sink in the back of the unit
also decrease the service life of the unit.

For optimal cooling conditions, mount the drive
on vertical position. Allow a free air passage

Enclosure type B1 B2/B3/B4

a [mm / inch] 100 / 3.94 200 / 7.87

b [mm / inch] 100 / 3.94 200 / 7.87

The drive cooling fans have small bearings into
which dust can penetrate and act as an abrasive.
This leads to bearing damage and fan failure.

Under the conditions described above, it is
advisable to clean the frequency converter
during periodic maintenance. Remove dust off
the heat sink and fans and clean the filter mats.

above and below the frequency converter.
See Table below:

a

b

18 AB237586440343en-000601

Horizontal mounting is NOT the preferred
position, however if unavoidable, lay PCB

on the left side (270°) to avoid condensation
accumulation on the electronics.

Drive installation

Ambient temperature The maximum ambient temperature for the drive

is 50°C.

Make sure that the clearance limits described
above are respected.

The drive must be installed on a wall or on a back
plate to ensure proper cooling.

Do not place the drive under direct sunlight.
Insulation inside the electrical panel can reduce
impact of sun radiation.

Test at the unit at highest ambient maximum
load is recommended. Look for over temperature
drive alarm.

The drive could operate lower to -10C with
proper operation, such as inside the cabinet,
install the space heater. However, LCP may not
function well under such low temperature.

GENERAL INFORMATIONPRODUCT INFORMATIONINTEGRATION INTO SYSTEMORDERING INFORMATION SYSTEM DESIGN

19AB237586440343en-000601

EMC installation

EMC best practices • Use screened (shielded) cables for motor, control

wiring and communication.

• Separate cables for input power, motor wiring
and control wiring. Failure to isolate power,
motor, control and communication cables
can result in unintended behavior or reduced
performance. Minimum 200 mm (7.9 in)
clearance between power, motor and control

GENERAL INFORMATIONPRODUCT INFORMATIONSYSTEM DESIGNINTEGRATION INTO SYSTEMORDERING INFORMATION

EMC correct installation

cables is required.

EMC qualification reports are available upon request to Danfoss technical support.

of an frequency drive
CDS303

PLC etc. Panel

• Ensure VFD proper grounding

• Motor cables should be as short as possible to
reduce noise level and leakage currents.

• Use the decoupling plate to fix and terminate
cables (Refer to

EMC correct installation of an

frequency drive CDS303)

• Add ferrite cores on power lines and earth line if
necessary to pass EMC class A.

PLC

SYSTEM DESIGN

Min. 0.025 in ²
(16 mm²)
Equalizing cable

Control cables

Min. 7.9 in
(200 mm)

Mains supply

L1
L2
L3
PE

Reinforced protective ground

between control
cables, motor cable
and mains cable

EMC remediation For some models, ferrite cores need to be added

to the input and/or output of CDS303 drive, as a

Compressor

Power size Voltage RFI filter

VZH052CJ 11kW T2 H2 - Y

CDS303 drive Remediation (ferrite cores)

Material: manganese zinc ferrite core

Drive input

Decoupling plate

Grounding rail

Cable insulation
stripped

All cable entries in
one side of panel

Motor cable

Motor, 3 phases and
protective ground

remediation, to fulfil the Class A Group 1 emission
and immunity requirements.

Material: nickel zinc ferrite core

Drive output

VZH052CG 11k W T4 H2 Y Y

VZH065CG 11k W T4 H2 Y Y

VZH065CG 15kW T4 H2 Y Y

VZH065CG 15kW T4 H3 - -

20 AB237586440343en-000601

EMC installation

UVWGround

EMC remediation To pass EMC class A, for the above models, ferrite

cores (4pcs) need to be added on both the power
lines and the earth line, in addition, a knot has
to be tied on each line. Ferrite core is a common

Ferrite core: each line should snatch one turn on it.
Ferrite cores should be as close as possible to the drive.

Mechanical dimension The dimension of the ferrite core depends on the

actual cable size, which should be specified by
the OEM depending on the unit design, ambient

anti-interference component in electronic
circuits, which helps to reduce electromagnetic
interference at different frequency.

GENERAL INFORMATIONPRODUCT INFORMATIONSYSTEM DESIGNINTEGRATION INTO SYSTEMORDERING INFORMATION

temperature, the wire material, current, etc. The
table below is a recommendation.

Wire sizes Mechanical dimension [mm / inch]

AWG mm

6 16 30 / 1.18 50 / 1.97 20 / 0.79

8 10 19 / 0.75 31.5 / 1. 24 12.5 / 0.49

10 6 19 / 0.75 31.5 / 1. 24 12.5 / 0.49

12 4 19 / 0.75 31.5 / 1.24 12.5 / 0.49

2

ID OD T

SYSTEM DESIGN

21AB237586440343en-000601

Unit Architecture

GENERAL INFORMATIONPRODUCT INFORMATIONSYSTEM DESIGNINTEGRATION INTO SYSTEMORDERING INFORMATION

L1
L2
L3
PE

Comp. ON /OFF

Relay

Unit Controller

Analogue out

SYSTEM DESIGN

Digital input

The frequency converter is pre-set for speed
open loop control. This means that the speed set­point is given by a 0-10V, where 0V corresponds
to the minimum compressor speed and 10V is
maximum compressor speed.

The unit controller must have full control of
the compressor operation and application
protections such as compressor envelope
control, oil return management and short cycling
protection.

Below is the Danfoss proposed system
configuration and wiring.

SCHEMATIC DIAGRAM

CDS 303

a

b

W

X

Y

Z

Start / Stop

HP switch

0-10V DC speed signal

+24V CC (150mA max.)

12

+24V CC

13

Digital Input

18

Digital Input

19

Digital Input

27

29

Digital Output
Digital Input

32

Digital Input

33

Digital Input Common

20

37

Safe Stop Input

Analog Output Common

39

42

Analog Output 1 0/4-20mA
+10V CC (15mA max.)

50
53

Analog Input 1
Analog Input 2

54
55

Analog Inputs Common

61

COM Serial

68

P Communication

69

N RS-485

3 phase

power input

50/60Hz

Motor output

Load sharing

Brake resistor

Relays

Relay 1

Relay 2

L1 91

L2
L3

PE

U
V
W

PE

+DC

R­R+

CM 01

NO

NC

CM

NO

NC

Fuses

92
93
95

96
97

98
99

88-DC

89
81

82

02

03

04

05
06

Contactor

T1
T2
T3
PE

VZH

Alarm

NOTE 1: Only relevant parameters or the ones different from factory defaults are shown.
NOTE 2: Oil boost, short cycle protection to be programmed in the unit controller
NOTE 3: Use Safe Stop for HP switch in CDS303 or use an output contactor (CDS803)

Drive parameters to adjust (See Note 1)

ID Name Setup 1 Factory Setup

341 Ramp 1 Ramp Up Time 180 30.00

342 Ramp 1 Ramp Down Time 180 30.00

512 Terminal 27 Digital Input No operation Stop inverse

54 0.1 Function Relay Alarm VLT running

2800 Short Cycle Protection Disabled Enabled

2810 Oil Return Management Off On

22 AB237586440343en-000601

Design piping

General requirements Proper piping practices should be employed to:

1. Ensure adequate oil return, even under
minimum load conditions (refrigerant speed,
piping slopes…). For validation tests see section
“Manage oil in the circuit”.

To condenser

HP

max. 4 m (13ft)

max. 4 m (13ft)

0.5% slope

4 m/s (13 ft/s)
or more

U-trap,

as short as possible
8 to 12 m/s
(26 to 40 ft/s)

0.5% slope

4m/s (13 ft/s) or more

U trap, as short as possible

LP

Evaporator

2. Avoid condensed liquid refrigerant from
draining back to the compressor when stopped
(discharge piping upper loop). For validation
tests see section “Manage off cycle migration”.

General recommendations are described in the
figures below:

Upper loop

HP

Condenser

LP

3D exibility

GENERAL INFORMATIONPRODUCT INFORMATIONSYSTEM DESIGNINTEGRATION INTO SYSTEMORDERING INFORMATION

3. Piping should be designed with adequate
three-dimensional flexibility to avoid excess
vibration. It should not be in contact with the
surrounding structure, unless a proper tubing
mount has been installed. For more information
on noise and vibration, see section on: “Sound
and vibration management”.

4. The design in this guideline is for short circuit
application. However, for long circuit and split
system application, an oil separator and an
external non-return valve are mandatory to use.

SYSTEM DESIGN

23AB237586440343en-000601

Design compressor mounting

General requirements

Single requirements

GENERAL INFORMATIONPRODUCT INFORMATIONSYSTEM DESIGNINTEGRATION INTO SYSTEMORDERING INFORMATION

Compressors used in single applications must be
mounted with flexible grommets.

All compressors are delivered with four rubber
grommets and metal sleeves. Compressors
must always be mounted with these grommets.
Recommended torque for mounting bolts: 11 Nm
(±1 Nm).

During operation, the maximum inclination from
the vertical plane must not exceed 7 degrees.

1.7

29.5

41

Recommended torque for
mounting bolts: 11 Nm (±1 Nm)

Ø 41

Ø11

Not supplied
with grommet

5/16" - 18 UNC
self tapping

SYSTEM DESIGN

24 AB237586440343en-000601

Manage oil in the circuit

Requirement

R

Oil level must be visible or full in the sight
glass when the compressor is running and when
all compressors of the circuit are stopped.

System evaluation

Single compressor

Non split Test N°1

1. Since each installation is unique, test can not validate

Split

the oil return, Oil separator is mandatory

2. Pay special attention to “Piping design” on field

3. Oil level must be checked and adjusted at
commissioning.

Test, criteria and solutions

Test N° Purpose Test condition Pass criteria Solutions

A

1. Top-up with oil, generally 1-2% of
the total system refrigerant charge

1

Check proper
oil return

Lowest foreseeable evaporation,
and highest foreseeable
condensation.
Minimum speed running 6 hours.
For reversible system, perform test
in both heating and cooling mode.

Oil level must be visible or full in the
sight glass when the compressor is
running.

(in weight). Above 3% look for
potential oil trap in the system.

2. Adjust oil boost function, for more
details see section”Oil management
logic”.

3. Oil separator can be added

GENERAL INFORMATIONPRODUCT INFORMATIONSYSTEM DESIGNINTEGRATION INTO SYSTEMORDERING INFORMATION

SYSTEM DESIGN

25AB237586440343en-000601

Manage sound and vibration

Typical sounds and vibrations in systems can be
broken down into the following three categories:

• Sound radiation (through air)

• Mechanical vibrations (through parts and
structure)

Compressor sound radiation

For sound radiating from the compressors,
the emission path is air and the sound waves
are travelling directly from the machine in all

GENERAL INFORMATIONPRODUCT INFORMATIONSYSTEM DESIGNINTEGRATION INTO SYSTEMORDERING INFORMATION

Compressor

model

VZH052-VZH065

Sound power and attenuation are given at ARI conditions, measured in free space
 Attenuation given with acoustic hood
Materials are UL approved

Frequency RPS

60 79 9 79 9 79 9

90 85 9 85 9 85 9

directions.

Sound power

dB(A)

200V 400V 575V

Attenuation

dBA 

Mitigations methods:

We can consider two means to reduce
compressors sound radiations:

1. Acoustic hoods are quick and easy to install

and do not increase the overall size of the
compressors. Acoustic hoods are available from
Danfoss as accessories. Refer to the table above
for sound levels, attenuation and code numbers.

2. Use of sound-insulation materials on the inside

of unit panels is also an effective means to reduce
radiation.

Sound power

dB(A)

Attenuation

dBA 

• Gas pulsation (through refrigerant)
The following sections focus on the causes and
methods of mitigation for each of the above
sources.

Sound levels are as follows:

• For compressors running alone:

Sound power

dB(A)

Attenuation

dBA 

Acoustic hood

code number

120Z50 84

Note: During compressor shut down, a short
reverse rotation sound is generated. The duration
of this sound depends on the pressure difference
at shut down and should be less than 3 seconds.
This phenomenon has no impact on compressor
reliability.

SYSTEM DESIGN

26 AB237586440343en-000601

Manage sound and vibration

Mechanical vibrations

A compressor generates some vibrations
that propagate into the surrounding parts
and structure. The vibration level of a VZH
compressor alone does not exceed 76 µm peak
to peak. However, when system structure natural
frequencies are close to running frequency,
vibrations are amplified due to resonance
phenomenon.

A high vibration level is damageable for piping
reliability and generates high sound levels.

Mitigations methods:

1. Danfoss VZH scroll compressors are designed
to produce minimal vibration during operations.
To ensure minimum vibrations transmission
to the structure, strictly follow mounting
requirements (mounting feet, rails etc..). For
further information on mounting requirements,
please refer to “Design compressor mounting”.

2. Ensure that there is no direct contact (without
insulation) between vibrating components and
structure.

This could be challenging on a variable system as
all resonant frequencies between min speed to
maximum speed will be exited.

It is mandatory to check that piping vibrations
are acceptable across speed range. This test
can be done by increasing slowly speed and
monitoring piping behavior through, strain gage,
acceleration, or displacement measurement.
As alternative visual check with strobe light can
also emphasis high piping displacement.

If some resonant frequencies generate high
piping vibration, problem can be solved by
increasing piping stiffness with brackets or
changing layout. Dampers can also be installed
to mitigate vibration.

If some frequencies continue to produce
unacceptable vibration levels, speed by-pass is
adjustable in the frequency converter, in order
to avoid some frequency ranges. Four by-pass
ranges are adjustable, and settings can be made
in parameter group 4-6.

GENERAL INFORMATIONPRODUCT INFORMATIONSYSTEM DESIGNINTEGRATION INTO SYSTEMORDERING INFORMATION

Gas pulsation

3. Resonance phenomenon
To avoid resonance phenomenon, pipings and
frame must have natural frequencies as far as
possible from running frequencies.

The Danfoss VZH scroll compressor has been
designed and tested to ensure that gas pulsation
is optimized for the most commonly encountered
air conditioning pressure ratio. Manifolded
compressors are equivalents to lagged sources
of gas pulsation. Therefore, pulse level can vary
during time.

Mitigations methods:

If an unacceptable level is identified, a discharge
muffler with the appropriate resonant volume
and mass can be installed.

SYSTEM DESIGN

27AB237586440343en-000601

Manage superheat

Requirement

System evaluation

GENERAL INFORMATIONPRODUCT INFORMATIONSYSTEM DESIGNINTEGRATION INTO SYSTEMORDERING INFORMATION

During normal operation, refrigerant enters
the compressor as a superheated vapor. Liquid
flood back occurs when a part of the refrigerant
entering the compressor is still in liquid state.

In steady state conditions the expansion device
must ensure a suction superheat within 5K to 30K
(9 to 54°F).

Use the table in relation with the application to
quickly evaluate the potential tests to perform.

Application Tests to perform

Non reversible Liquid flood back test

Reversible

Liquid flood back test

Defrost test

Liquid flood back can cause oil dilution and, in
extreme situations lead to liquid slugging that
can damage compression parts.

SYSTEM DESIGN

28 AB237586440343en-000601

Manage superheat

Test, criteria and solutions

Test N° Purpose Test condition Pass criteria Solutions

Liquid flood back testing must be
carried out under expansion valve
threshold operating conditions:

•Lowest foreseeable evaporation,
and highest foreseeable
condensation.

•Minimum speed running.

Liquid flood
back test

Steady-state

Trans ient

For reversible system, perform test
in both heating and cooling mode

A

Tests must be carried out with most
unfavorable conditions :

• fan staging,

• compressor staging

• …

Suction superheat >5K

1. Check expansion valve selection
and setting.

-For Thermostatic expansion valve
(TXV) check bulb position...

-For Electronic expansion valve
(EXV) check measurement chain and

PID....

2. Add a suction accumulator*.

Oil superheat shall not be more than
30 sec below the safe limit defined in
the Dilution Chart. (see graph above)

GENERAL INFORMATIONPRODUCT INFORMATIONSYSTEM DESIGNINTEGRATION INTO SYSTEMORDERING INFORMATION

1.Check defrost logic.

Defrost test

Check liquid
floodback
during defrost
cycle

Defrost test must be carried
out in the most unfavorable
condition at 0°C (32°F) evaporating
temperature).

Oil superheat shall not be more than
30 sec below the safe limit defined in
the Dilution Chart. (see graph ablve)

In reversible systems, the defrost
logic can be worked out to limit
liquid floodback effect. (for more
details see “Control Logic”).

2. Add a suction accumulator*.

*Suction accumulator offers protection by trapping the liquid refrigerant upstream from the compressor. The accumulator should be sized at least 50 % of the total system
charge. Suction accumulator dimensions can impact oil return (gas velocity, oil return hole size…), therefore oil return has to be checked according to section “Manage oil in the
circuit”.

Dilution chart

(reference at 20°C / 68°F ambient temperature)

-22 -13 -4 514230 32 50 59 68 773086

18

16

14

12

10

8

6

Oil Superheat (K)

4

2

0

-30 -25 -20 -15 -10 -5 0510 15 20 25

Evaporating Temperature °F

Acceptable

Evaporating Temperature °C

Unacceptable

32

29

25

22

18

14

11

Oil Superheat (°F)

7

4

0

SYSTEM DESIGN

Oil temperature sensor must be placed between
oil sight glass and compressor baseplate. Some
thermal paste shall be used to improve the
conductivity. The sensor must also be correctly
thermally insulated from the ambiance.

The Oil superheat is defined as:
(Oil temperature - Evaporating temperature)

29AB237586440343en-000601

Manage off cycle migration

Requirement

GENERAL INFORMATIONPRODUCT INFORMATIONSYSTEM DESIGNINTEGRATION INTO SYSTEMORDERING INFORMATION

System evaluation

R

Off -cycle refrigerant migration happens:

• when the compressor is located at the coldest

part of the installation, refrigerant vapor
condenses in the compressor.

• or directly in liquid-phase by gravity or pressure

difference.

· Compressor can tolerate occasional flooded

start, but it should remain exceptional situation
and unit design must prevent that this situation
from happening at each start.

When the compressor restarts, the refrigerant
diluted in the oil, or stored in evaporator,
generates poor lubrication conditions, and may
reduce bearings life time. In extreme situations,
this leads to liquid slugging that can damage the
compressor scroll set.

· The charge limit is a threshold beyond with
some protective measures must be taken to
limit risk of liquid slugging and extreme dilution
at start.

· Right after start, liquid refrigerant must not flow
massively to compressor.

Use the table below in relation with the system
charge and the application to quickly define
necessary safeties to implement.

Application BELOW charge limit ABOVE charge limit

Ensure tightness between condenser & evaporator when system is OFF

• Thermostatic expansion Valve (TXV), Liquid Line Solenoid Valve LLSV** strongly

All

Non split No test or additional safeties required

recommended

• Electronic expansion valve (EXV) must close when system stops including in power shut
down situation

• Belt type heater*

• External Non-Return Valve

SYSTEM DESIGN

Since each installation is unique, refrigerant charge may vary

Split

• Belt type heater*

• Liquid Line Solenoid Valve**+ pump-down cycle***

• External Non-Return Valve

Charge limit is defined in table below:

Models Refrigerant charge limit (kg / lb)

Single VZH052-065 5.4 / 12

30 AB237586440343en-000601

Manage off cycle migration

*Crankcase heater
The belt crankcase heaters are designed to
protect the compressor against off-cycle
migration of refrigerant.
Additional heater power or thermal insulation
might be needed in case of ambient temperature
below -5°C (23°F) and a wind speed above
5m/second (16.4 feet/second).
The heater must be turned on whenever all the
compressors are off.
Cranckcase heater accessories are available from
Danfoss (see section “Accessories”).

Optimum
location area

**Liquid line solenoid valve (LLSV)
A LLSV is used to isolate the liquid charge
on the condenser side, thereby preventing
against charge transfer to the compressor
during off -cycles. The quantity of refrigerant
on the low-pressure side of the system can be
further reduced by using a pump-down cycle in
association with the LLSV.

***Pump-down cycle
By decreasing pressure in the sump, pump down:

• Evacuates refrigerant from oil

• Set the sump saturating pressure much
lower than ambiance temperature and due
to that, avoid refrigerant condensation in the
compressor.

• Pump-down must be set higher than 1.8 bar(g)
/ 26 psig.

For more details on pump-down cycle see
section “Control Logic”.

GENERAL INFORMATIONPRODUCT INFORMATIONSYSTEM DESIGNINTEGRATION INTO SYSTEMORDERING INFORMATION

SYSTEM DESIGN

31AB237586440343en-000601

Manage operating envelope

Requirement

Single envelope control

GENERAL INFORMATIONPRODUCT INFORMATIONSYSTEM DESIGNINTEGRATION INTO SYSTEMORDERING INFORMATION

R

The operating envelope for VZH scroll
compressors is given in the figures below and
guarantees reliable operations of the compressor
for steady-state operation.

VZH operating envelop - R410A(SH5K/9°F) Voltage: 200-240V/380-480V/525-600V

Evaporating temperature (°F)

-40 -31 -22 -13 -4 5 14 23 32 41 50 59 68 77 86

70

65

60

55

50

45

40

35

30

25

20

Condensing temperature (°C)

15

10

5

0

-40

-35 -30 -25 -20 -15 -10 -5 0 5 10 15 20 25 30

4200-6000rpm

Evaporating temperature (°C)

1.4

Moreover, the discharge gas temperature must
not exceed 135°C (275°F). Steady-state operation
envelope is valid for a suction superheat within
5K to 30K (9°F to 54°F) range.

158

149

140

131

122

113

104

95

86

77

68

59

50

41

32

1800-6600rpm

1.2

1.1

1000-6600rpm

2400-6000rpm

1.3

Condensing temperature (°F)

SYSTEM DESIGN

Note:
zone1.1/1.2/1.3: reliable running, compressor discharge temperature will not exceed 135°C (275°F) with suction

zone 1.4: Restricted area, compressor discharge temperature may go beyond 135°C (275°F) depending on superheat

superheat within 5K to 30K (9°F to 54°F) range

and speed. Operation in this area is allowed if discharge temperature is below 135°C (275°F).

Pressure settings R410A

Working range high side bar(g)
psig

Working range low side bar(g)
psig

Maximum high pressure safety switch setting* bar(g)
psig

Minimum low pressure safety switch setting bar(g)
psig

9.9 -41.1

144 -596

1.8-16. 6
26 -241

43.7
634

1.5
22

1.5 bar below nominal evap. pressure with
Minimum low pressure pump-down switch setting bar(g)
psig

22 psi below nominal evap. pressure with

minimum of 1.8 bar(g)

minimum of 26psig

*Maximum allowable pressure on high pressure side according to PED regulation.

32 AB237586440343en-000601

Manage operating envelope

System evaluation

VZH drive can only protect the compressor from
over current. To manage operating envelop, an

permanently checking that the compressor is

running within the defined envelope.
advanced envelope protection principle needs
to be used with variable speed compressors.
This solution offers much better protection than

When compressor reach a limit, controller can act

on different parameter to avoid unit tripping.
basic protection, and also offers the possibility
to adjust running conditions to avoid tripping
(for example reduce compressor speed when
reaching high pressure limit).

The advanced protection principle is based
on a permanent measurement of suction

On top of suction and discharge pressure

limitations, the discharge T° must remain below

135°C (275°F).

Low pressure switch and high pressure switch

remain necessary as an ultimate protection.
and discharge pressure. Unit controller is

The whole envelope can be used on the whole

• Speed range limited from 2400RPM to 6000RPM

speed range, see “Single application envelope”

• Full speed range from 1000RPM to 6000RPM
Depending on speed range needed, two types of
controls to be considered

Single envelope control: Limit speed range from 2400 to 6000RPM

Controller do not need to manage speed

Operation is allowed in area 1.1; 1.2 ; 1.3.

limitation according to operating conditions.

GENERAL INFORMATIONPRODUCT INFORMATIONSYSTEM DESIGNINTEGRATION INTO SYSTEMORDERING INFORMATION

Protection required

• HP switch*

• LP switch*

• DGT set @ 135°C (275°F) if necessary see “Discharge T°
protection”

• Measurements of suction and discharge pressure,
unit controller with is permanently maintaining
compressor within its envelope.

• drive setting:

parameter 4-11[ Motor speed low limit(rpm)]:
set value as 2400

HP switch setting

DGT

4200-6000rpm

2400-6000rpm

LP switch setting

Condensing pressure control

MOP

ratio

Minimum pressure

SYSTEM DESIGN

33AB237586440343en-000601

Manage operating envelope

Multiple envelope control: Speed range <2400 allowed

GENERAL INFORMATIONPRODUCT INFORMATIONSYSTEM DESIGNINTEGRATION INTO SYSTEMORDERING INFORMATION

Controller needs to manage speed limitation
according to operating conditions.
1000RPM to 1800RPM is allowed in area 1.1
1800RPM to 2400RPM is allowed in area 1.1 and

1.2

Protection required

• HP switch*

• LP switch*

• DGT set @ 135°C (275°F) if necessary
see §Discharge T° protection

•Measurements of suction and discharge pressure,
unit controller is permanently maintaining compressor
within its envelope with right minimum speed

•drive setting:
parameter 4-11[ Motor speed low limit(rpm)]: keep
default value as 1000

*for more details see “Control Logic”

Test N° Purpose Test condition Pass criteria Solutions

1

Check reaction
of system to oil

boost

Stabilized the system in area below

minimum speed (2400RPM) until oil

boost happen

No unsafties happen

Superheat requirement fullfilled

2400RPM to 6000RPM is allowed in area 1.1; 1.2
and 1.3
4200RPM to 6000RPM is allowed in all area
Below 2400RPM oil boost function is enabled by
default (more details “Oil management logic”)

See “Test, criteria and solutions”

HP switch

DGT

4200-6000rpm

LP switch

Condensing pressure control

Perform oil boost test 1 described below

2400-6000rpm

1800-6600rpm

1000-6600rpm

Minimum pressure ratio

Modify ramp-up

Modify superheat control

MOP control

SYSTEM DESIGN

34 AB237586440343en-000601

Manage operating envelope

Bracket

Discharge temperature
protection

For VZH052-065 compressors, the external
Discharge Gas Temperature protection (DGT)
is required in zone 1.4 or if the high and low
pressure switch settings do not protect the
compressor against operation beyond its

70

65

60

55

50

45

40

35

30

25

20

Condensing temperature (°C)

15

10

5

0

-40

-35 -30 -25 -20 -15 -10 -5 0 5 10 15 20 25 30

Example 1 (R410A, SH = 6K / 10.8°F)
LP switch setting:
LP1 = 3.3 bar (g) / 48 psig (-15.5°C / 4.1°F)
HP switch setting:
HP1 = 38 bar (g) / 551 psig (62°C / 143.6°F)
Risk of operation beyond the application envelope.
DGT protection required.

DGT limit

Evaporating temperature (°C)

specific application envelope. Please refer to
the examples below, which illustrate where DGT
protection is required (Ex. 1) and where it is not
(Ex. 2). Please notice the envelope boundaries
change based on different speed limits.

LP1

Example 1

Example 2

Example 2 (R410A, SH = 6 K / 10.8°F)
LP switch setting:
LP2 = 4.6 bar (g) / 67 psig (-10.5°C / 13.1°F)
HP switch setting:
HP2 = 31 bar (g) / 450 psig (52°C / 125.6°F)
No risk of operation beyond the application envelope.

LP2

GENERAL INFORMATIONPRODUCT INFORMATIONSYSTEM DESIGNINTEGRATION INTO SYSTEMORDERING INFORMATION

A discharge gas temperature protection device
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.

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.

The discharge gas thermostat accessory kit (code

7750009) includes all components required
for installation as shown on the right. DGT
installation must respect below requirements:

• The thermostat must be attached to the
discharge line within 150 mm (5.91 inch) from
the compressor discharge port and must be
thermally insulated and tightly fixed on the
pipe.

• The DGT should be set to open at a discharge
gas temperature of 135°C (275°F) or lower.

Thermostat

Discharge line

Insulation

SYSTEM DESIGN

35AB237586440343en-000601

Manage operating envelope

MOP (Max operating
pressure) control

GENERAL INFORMATIONPRODUCT INFORMATIONSYSTEM DESIGNINTEGRATION INTO SYSTEMORDERING INFORMATION

Condensing pressure
control

Minimum pressure ratio

In steady state, it is essential to prevent the
compressor running when evaporating T° is
higher than the specified envelope. Operating
the compressor higher than maximum
evaporating temperature will cause low viscosity
of lubricant and lead to high dilution. Eventually
the compressor will get damaged.

This protection can be achieved by using MOP
function on expansion device. MOP is a feature
added to EXV’s (also to TXV’s) that limit the
maximum suction pressure of the unit. The
customer would need to set this at the 27°C

In steady state, the condensing T° must be
maintained at a T° within envelope. This can be
done by using fan speed controller, or constant
pressure valve. Keep condensing pressure at a
minimum level is also important to maintain
the pressure differential across the thermostatic
expansion valve and prevent cut out on the LP

In steady state, the pressure ratio must be a
T° within envelope. 2 type of control can be
considered:

• Set the minimum condensing T° at 30°C (86°F)
together with MOP set at 27°C (80.6°F).

(80.6°F) limit we have on our VS operating
envelope.

Regardless of EXV or TXV, customer needs to
qualify the expansion device. Testing needs to be
done at both max and min operating conditions
to guarantee the valve closes enough on the min
and opens far enough on the max.

Complementary to MOP, the unit controller can
increase compressor speed to keep evaporating
T° lower than limit.

protection in cold ambient.

As an alternative the unit controller can increase
compressor speed to keep condensing T° lower
than limit.

• Unit controller monitors permanently
Condensing and Evaporating T°, and adjust
compressor speed or condensing T° to keep
running conditions within envelope.

SYSTEM DESIGN

36 AB237586440343en-000601

Manage speed limit

Speed limit requirement

Speed limit guarantees compressor

R

reliability and must be respected. In drive control
logic, default setting values have been qualified

Start/Stop/Ramp setting

6000

Speed (RPM)

Start delay 1-71

3000

Start ramp up 3-82

0

7.5s

Drive parameter Description

Ramp 1 ramp up time 3-41

60s 15s Time (s)

by Danfoss. Customer could change the default
values if the changes have been qualified by
OEM.

GENERAL INFORMATIONPRODUCT INFORMATIONSYSTEM DESIGNINTEGRATION INTO SYSTEMORDERING INFORMATION

Ramp 1 ramp down time 3-42

To Stop 3-82

Default value

(s)

1-71 Start delay keep running @ 3000 RPM within a certain duration 60

It is used to define speed ramp up slope. Speed ramp up slope is defined under condition that increases

compressor speed from 0 rpm to 6000 rpm in a certain period(s, ramp1 ramp up time)

Eg: if current speed is 3000rpm and desired speed is 4000rpm,

then compressor will reach 4000 rpm in 15s

It is used to define speed ramp down slope. Speed ramp down slope is defined under condition that

decreases compressor speed from 6000 rpm to 0rpm in a certain period

(s, ramp1 ramp down time)

Eg: if current speed is 4000rpm and desired speed is 3000rpm,

then compressor will reach 3000 rpm in 5s

3- 41

3-42

Ramp 1 ramp

up time

Ramp 1 ramp

down time

90

SYSTEM DESIGN

30

37AB237586440343en-000601

Control logic

Safety control logic requirements

HP switch

LP safety switch

GENERAL INFORMATIONPRODUCT INFORMATIONSYSTEM DESIGNINTEGRATION INTO SYSTEMORDERING INFORMATION

Tripping conditions Re-start conditions

Value Time Value Time

See Pressure settings table

from section “Manage

operating envelope”

Immediate, no delay.

No by- pass

Conditions back to normal.

Switch closed again

Manual reset

Maximum 5 auto reset during

a period of 12 hours, then

manual reset.

High pressure According to EN378-2, a high-pressure (HP) safety

switch is required to shut down the compressor.
The high-pressure switch can be set to lower
values depending on the application and
ambient conditions. The HP switch must either be
placed in a lockout circuit or consist of a manual
reset device to prevent cycling around the high-

Low pressure A low-pressure (LP) safety switch must be

used. Deep vacuum operations of a scroll
compressor can cause internal electrical arcing
and scroll instability. VZH compressors exhibit
high volumetric efficiency and may draw very
low vacuum levels, which could induce such
a problem. The minimum low-pressure safety
switch (loss-of-charge safety switch) setting is
given in the following table. For systems without
pump-down, the LP safety switch must either be
a manual lockout device or an automatic switch

SYSTEM DESIGN

Electronic expansion valve

With variable capacity systems, an electronic
expansion valve (EXV) is the strongly
recommended solution to handle refrigerant
mass flow variations. Danfoss recommends the
use of ETS products. Ramp-up and ramp-down
settings, of both EXV and compressor, must be
done with great care.

pressure limit. If a discharge valve is used, the HP
switch must be connected to the service valve
gauge port, which must not be isolated. The HP
switch must be connected to the CDS303 input
37 or an external contactor placed before and
after the drive.

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. Lock-out circuit or
LP switch or series with other safety devices must
be connected to CDS303 input 27.

OEM need to set port 27 to “coast inverse or
external interlock” to get rid of minimum running
time restriction.

compressor. The EXV can also be opened, up
to a certain degree, before the start up of the
compressor.

Ramp-down of the EXV must be longer than the
ramp-down of the compressor, also to avoid low
pressure operation (except with pump-down).

Reverse rotation protection

38 AB237586440343en-000601

Ramp-up of the EXV must be shorter than
the ramp-up of the compressor, to avoid any
low pressure operation on suction side of the

Due to drive protection, compressors could work
properly even if the power connection between
the drive and mains is dis-matched. However, the
wires between compressor and drive must be
connected accordingly. To protect compressors
from reverse rotation, pressure difference could

EXV should be closed, and remain closed,
when the compressor is off, to avoid any liquid
refrigerant entering the compressor.

be checked as a reference value. Use pressure
sensors to monitor pressure difference between
discharge and suction of the compressor, and for
normal operation, discharge pressure should be
at least 1 bar higher than suction pressure within
30 s running after compressor starting.

Control logic

Short cycle protection Short cycling protection requirements need to be

implemented in OEM unit controller:

Meantime, the factory default setting needs to
be disabled( 28-00 short cycle protection change
from default setting “enable” to “disable”).

- 3 minutes minimum running time: in order to
get oil return back from circuit to compressor
sump

Defrost cycle logic In reversible systems, the defrost logic can be

worked out to limit liquid flood back effect by:

1. Running full load during defrost to share liquid
refrigerant between all compressors.

The following defrost logic combines both
advantages:

Compressor

4WV

EXV

ON

Heating

100%

- 12 starts maximum per hour: to avoid threaten
the life time of motor and other mechanics due
to frequent starts, OEM needs to limit the starts
cycles within 12 times per hour.

- 10s minimum OFF time: to make sure discharge
valve is closed and motor is stopped before next
start, OEM needs to set the minimum off time as
10 seconds.

GENERAL INFORMATIONPRODUCT INFORMATIONSYSTEM DESIGNINTEGRATION INTO SYSTEMORDERING INFORMATION

2. Transferring liquid refrigerant from one
exchanger to the other one thanks to pressures.

Defrost start. Stop the compressor

Pump-down logic recommendations

When pressures are almost balanced,

4 Way Valve (4WV) stays in heating mode.

EXV opened to transfer liquid from

outdoor to indoor exchanger thanks to

pressure difference

change 4WV to cooling mode.

* EXV Opening degree and time have to be set
to keep a minimum pressure for 4 way valve
moving.

Pump down is initiated prior to shutting
down the last compressor on the circuit by
de-energizing a liquid line solenoid valve
or closing electronic expansion valve. When
suction pressure reaches the cut-out pressure,
compressor is stopped, and liquid solenoid valve
or electronic expansion valve remains closed.
Two types of pump-down exist:

Start the compressor

Defrost

4 WV stays in cooling mode.

EXV opened to transfer liquid

Defrost end. Stop the compressor

from indoor to outdoor exchanger

thanks to pressure difference

Danfoss recommend above defrost cycle logic,
but the control logic is also system specified.

In any case, defrost logics must respect
requirements and tests described in “Manage
superheat” and “Manage operating envelope”.

• One shot pump down (preferred): when
last compressor of the circuit stops, suction
presssure is decreased 1.5 bar below nominal
evaporating pressure. Even if suction pressure
increases again, the compressor will not restart.

• Continuous pump-down: traditional pump­dow, Compressor restarts automatically when
suction pressure increases up to 4 cycles
maximum. A non-return valve in the discharge
line is recommended.

Start the compressor, run the

When pressures are almost balanced,

change 4WV to heating mode.

compressor at 50rps for 1min.

Afterwards, go to the set speed.

SYSTEM DESIGN

39AB237586440343en-000601

Control logic

Oil management logic

GENERAL INFORMATIONPRODUCT INFORMATIONSYSTEM DESIGNINTEGRATION INTO SYSTEMORDERING INFORMATION

SYSTEM DESIGN

CDS303 integrates oil return management(ORM)
function together with compressor oil boost
function.

3600rpm

Decrease ORM

2400rpm

2811-ORM Low Speed

Running time expire

time

Increase ORM

time

2812-boost inter val

• Oil boost function: If compressor runs below
2400 rpm for more than 120 minutes (low speed
running time, 28-11), in case oil get trapped
in system and compressor inner part cannot
get lubricated, CDS303 oil boost function will
accelerate compressor speed to 3600 rpm for 1
minute (minimum duration, includes ramp up
time, 28-13) to take the oil back from system.
In case of slow acceleration condition, please
make sure compressor maintain minimum speed
3600rpm for at least 1 minute running.

* Please note for oil boost function, it is enabled
by parameter 28-10 as default setting. Please
notice when hands on mode is selected, oil
return management will not work even if
parameter 28-10 (oil return management) is set
to on. During hands on mode, if compressor
runs below 2400rpm for more than 120 minutes,

This function uses a timer.
The timer is set at parameter low speed running
time 28.11, 120min.
When actual compressor speed is below 40rps,
the timer is increasing. When compressor speed
is above 40rps timer is decreasing.
When time counter reaches 120min the oil return
boost is started.
When the boost is terminated, the compressor
speed goes back to run on reference (speed
setpoint) and the time counter is reset and
restarting from zero.

oil return fault alarm (A208) will report on
LCP and stop the compressor. Please select
hands on mode carefully and only select hands
on mode if the OEM has implemented oil
return management in the system controller
and qualified oil management. Under such
conditions, the compressor could run below
2400rpm continually and meanwhile drive oil
return management 28-10 will get by passed..

• Oil return function: To double ensure oil
return from system, compressor speed will
boost to 3600 rpm at a fixed time intervals (as
programmed in parameter 28-12, default 24 hrs)
any way.

40 AB237586440343en-000601

ID Name Factory Setup Unit Customer Access

2810 Oil Return Management Enable R/W

2811 Low Speed Running Time 120 min R/W

2812 Fixed Boost Interval 24 h R/W

2813 Boost Duration 60 s R/W

Oil management related parameters, 28-11, 28­12, 28-13 could also be programmed by OEM.

Considering oil return risk, a split system
with more than 10 m piping length requires
mandatory application approval by Danfoss
application specialists.

Reduce moisture in the system

Requirements

Solutions

Excessive air and moisture

• can increase condensing pressure and cause
excessively high discharge temperatures.

• can create acid giving rise to copper platting.

• can destroy the lubricating properties of the oil.

VZH compressors are delivered with < 100 ppm
moisture level.
At the time of commissioning, system moisture
content may be up to 100 ppm.

To achieve this requirement, a properly sized
and type of drier is required. Important selection
criteria’s include:

• driers water content capacity,

• system refrigeration capacity,

• system refrigerant charge.

All these phenomena can reduce service life
and cause mechanical and electrical compressor
failure.

During operation, the filter drier must reduce this
to a level between 20 and 50 ppm.

GENERAL INFORMATIONPRODUCT INFORMATIONSYSTEM DESIGNINTEGRATION INTO SYSTEMORDERING INFORMATION

For new installations with VZH compressors with
PVE oil, Danfoss recommends using the Danfoss
DML (100% molecular sieve) solid core filter drier.

SYSTEM DESIGN

41AB237586440343en-000601

Assembly line procedure

Compressor storage

Compressor holding charge

GENERAL INFORMATIONPRODUCT INFORMATIONSYSTEM DESIGNORDERING INFORMATION INTEGRATION INTO SYSTEM

Handling

- Store the compressor where is not exposed to
rain, corrosive or flammable atmosphere.

- Store the compressor between

-35°C and 70°C (-31°F and 158°F) when it is
charged with nitrogen.

Each compressor is shipped with a nominal dry
nitrogen holding charge between 0.3 and 0.7 bar
(4 psi and 10 psi) and is sealed with elastomer
plugs.

Respect the following sequence:

• Remove the nitrogen holding charge via the
suction Schrader valve to avoid an oil mist blow
out.

Each Danfoss VZH scroll compressor is
equipped with one lift ring on the top shell.

• Always use one lift ring and discharge tube
when lifting the compressor.

• Use lifting equipment rated and certified for
the weight of the compressor or compressor
assembly.

• A spreader bar rated for the weight of the
compressor is highly recommended to ensure a
better load distribution.

- Store the compressor between -35°C and 55°C
(-31°F and 131°F) when it is charged with R410A
refrigerant.

• Remove the suction plug first and the discharge
plug afterwards to avoid discharge check valve
gets stuck in open position.
An opened compressor must not be exposed to
air for more than 20 minutes to avoid moisture is
captured by the PVE oil.

• The use of lifting hooks closed with a clasp is
recommended.

• Never use the lift rings on the compressor to lift
the full unit.

Maintain the compressor in an upright position
during all handling manoeuvres (maximum of
15° from vertical).

HEAVY

do not lift
manually

42 AB237586440343en-000601

Assembly line procedure

Piping assembly Good practices for piping assembly is a pre-requisite to ensure compressor service life (system

cleanliness, brazing procedure...)

System cleanliness

Circuit contamination possible cause Requirement

Brazing and welding oxides During brazing, flow nitrogen through the system

Filings and particles from the removal of burrs in
pipe-work

Moisture and air

Remove any particles and burrs generated by tube
cutting and hole drilling

Use only clean and dehydrated refrigeration grade
copper tubing
Opened compressor must not be exposed to air more
than 20 minutes to avoid moisture captured by PVE oil.

GENERAL INFORMATIONPRODUCT INFORMATIONSYSTEM DESIGNORDERING INFORMATION INTEGRATION INTO SYSTEM

System pressure test and leak detection

Brazing procedure:

• Brazing operations must be performed by
qualified personnel.

• Make sure that no electrical wiring is connected
to the compressor.

• To prevent compressor shell and electrical box

overheating, use a heat shield and/or a heat­absorbent compound.

• Clean up connections with degreasing agent

• Flow nitrogen through the compressor.

• Use flux in paste or flux coated brazing rod.

Before eventual un-brazing of the
compressor or any system component, the
refrigerant charge must be removed.

The compressor has been strength tested
and leak proof tested (<3g/year) at the factory.
For system tests:

• Always use an inert gas such as Nitrogen or

Helium.

• Use brazing rod with a minimum of 5% silver
content.

• It is recommended to use double-tipped torch
using acetylene to ensure a uniform heating of
connection.

• To enhance the resistance to rust, a varnish on

the connection is recommended.

heat shield

C

A

B

• Pressurize the system on HP side first then LP
side.

• Do not exceed the following pressures:

Maximum compressor test pressures

Maximum compressor test pressure high side (HP)

Maximum compressor test pressure low side (LP)

* If an external non return valve is present on the discharge line, maximum pressurizing speed must be respected to ensure pressure
equalization between LP and HP side over scroll elements.

41.1 bar (g) / 596 psig

HP-LP<36bar / 522 psi

33.3 bar (g) / 483 psig

LP-HP<5bar / 73 psi
Maximum speed 4,8 bar/ second (70 psi/s)*

43AB237586440343en-000601

Assembly line procedure

Vacuum evacuation and moisture removal

GENERAL INFORMATIONPRODUCT INFORMATIONSYSTEM DESIGNINTEGRATION INTO SYSTEMORDERING INFORMATION

Refrigerant charging

R

Requirements:

• Never use the compressor to evacuate the
system.

• Connect a vacuum pump to both the LP and HP
sides.

• Evacuate the system to a pressure of 500 μm Hg
(0.67 mbar / 0.02 in.Hg) absolute.

R

Initial charge:

• For the initial charge, the compressor must not
run.

• Charge refrigerant as close as possible to the
nominal system charge.

• This initial charging operation must be done in
liquid phase between the condenser outlet and
the filter drier.

Recommendations:

• Energized heaters improve moisture removal.

• Alternate vacuum phases and break vacuum.
with Nitrogen to improve moisture removal.

For more detailed information see “Vacuum
pump-down and dehydration procedure”
TI-026-0302.

If needed, a complement of charge can be done:

• In liquid phase while compressor is running by
slowly throttling liquid in.

• Never bypass safety low pressure switch.

For more detailed information see
“Recommended refrigerant system charging
practice“ FRCC.EN.050.

Dielectric strength and insulation resistance tests

INTEGRATION INTO SYSTEM

The tests are performed on each compressor at
the factory between each phase and ground.

• Carry out a dielectric strength test by short­circuiting terminals L1, L2 and L3. Energize by
max. 1920 V DC(hi-pot) for code G compressors
and 1460 V DC(hi-pot) for code J compressors
for one second between this short-circuit and
the chassis, and leakage current must be less
than 5 mA. When running dielectric strength
tests of the entire installation, frequency
converter and compressor electrical motor
compressor test can be conducted together.
When conducting a dielectric strength test,
make sure the system is not under vacuum: this
may cause electrical motor compressor failure.

R

Do not use a megohm meter nor apply
power to the compressor while it is under
vacuum as this may cause internal damage.

Please note, it is not recommended that a
dielectric strength test be carried out too often
as it may damage the motor. Nevertheless, if
such a test is necessary, it must be performed at
a lower voltage.

• Insulation resistance is measured with a 500 V
DC megohm tester and must be higher than 1
megohm.

• The presence of refrigerant around the

motor windings will result in lower resistance
values to ground and higher leakage current
readings. Such readings do not indicate a faulty
compressor. To prevent this, the system can be
first operated briefly to distribute refrigerant.

44 AB237586440343en-000601

Commissioning

Preliminary check

Check electrical power supply:

• Phase order: Reverse rotation is obvious if the
compressor do not build up pressure and sound
level is abnormal high. VZH compressor will only
operate properly in one direction. If electrical
connections are done correctly between the
drive and the compressor terminals (compressor

terminals T1,T2,T3 and drive terminals U, V & W
matching), the drive will provide correct phase
supply to the compressor, and reverse rotation
will be not possible:For more details refer to
“Motor protection”.

• Voltage and voltage unbalance within tolerance:
For more details refer to section “Motor voltage”.

Initial start-up

System monitoring

• Cranckcase heaters must be energized at least 6
hours in advance to remove refrigerant.

• 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

The system must be monitored after initial
startup for a minimum of 60 minutes to ensure
proper operating characteristics such as:

• Proper metering device operation and desired

superheat readings

• Suction and discharge pressure are within

acceptable levels

• Correct oil level in compressor sump indicating

proper oil return

• Low foaming in sight glass and compressor

sump temperature 10K (18°F) above saturation
temperature to show that there is no refrigerant
migration taking place

• Acceptable cycling rate of compressors,

including duration of run times.

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.

A short cycling protection is provided in the CDS
frequency converter. It is factory preset “enabled”
with the following parameters in:

28.01 - interval between 2 starts: 300 secondes

28.02 - minimum run time: 60 seconds.

This minimum run time is set to guaranty long
enough running time at start up in order to
create enough refrigerant flow velocity in the
system to recover the oil to the compressor
sump.

• Current draw of compressor within acceptable
values (RLA ratings)

• No abnormal vibrations and noise.

GENERAL INFORMATIONPRODUCT INFORMATIONSYSTEM DESIGNINTEGRATION INTO SYSTEMORDERING INFORMATION

Oil level checking and top-up

In installations with good oil return and line runs
up to 15 m (49 feet), no additional oil is required.
If installation lines exceed 15 m (49 feet),
additional oil may be needed. 1 or 2% of the total
system refrigerant charge (in kg) can be used to
roughly define the required oil top-up quantity
(in liters) but in any case the oil charge has to be
adjusted based on the oil level in the compressor
sight glass.

When the compressor is running under stabilized
conditions, the oil level must be visible in the
sight glass.

The presence of foam filling in the sight glass
indicates large concentration of refrigerant in the
oil and / or presence of liquid returning to the
compressor.

The oil level can also be checked a few minutes
after the compressor stops, the level must be
between 1/4 and 3/4 of sight glass.

When the compressor is off, the level in the
sight glass can be influenced by the presence of
refrigerant in the oil.

INTEGRATION INTO SYSTEM

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
filling in instructions for Danfoss Commercial
Compressors” TI 2-025-0402.

45AB237586440343en-000601

Troubleshooting

GENERAL INFORMATIONPRODUCT INFORMATIONSYSTEM DESIGNINTEGRATION INTO SYSTEMORDERING INFORMATION

CD warning

CD switches

to Alarm

VZH Compressor

not working

Power output

yes no

from CDS303

drive ?

#12 #13

Check alarm #

VZH blocked

VZH to be

replaced

Check oil level

Piping check

oil return

Reset & Start

Check alarm #

(Continue)

#14

Earth Fault

Output side

#16

Short circuit

Output side

Torque limit

Check VZH + CDS303

#30,31,32

Motor phase

compatibility

Replace

relevant part

missing

Over current

Check motor current

&Settings

Control Comp

Working load/map

Mains Shut off

& reset

#38

Internal fault

INTEGRATION INTO SYSTEM

46 AB237586440343en-000601

Check motor

cable

Check VZH

Motor resistance

and isolation

Correct

the fault

Mains shut-off

before

checking !

Reset &

start

Setting Error(s)

Come back to

factory settings

Incompatibility

Between

Software &

Additional option

Contact your

Local Danfoss

Troubleshooting

Check alarm #

(Continue)

#29

Drive over

temperature

Ambiant temp.

Too high or fan damaged

Electrical cabinet

Poor ventilation

Dirt on

CDS303 coil

Air by-pass
Or recycled

Missing

CDS303 back side

Metal sheet

Turn off power

Reset & start

#65 #68

Control card

Over temp.

direct wire

Check

connections

Safe stop

activated

Check 24V

On 12/13
terminals

24V supply to

terminal 37

Reset & start

GENERAL INFORMATIONPRODUCT INFORMATIONSYSTEM DESIGNINTEGRATION INTO SYSTEMORDERING INFORMATION

Check external

controls

Check alarm #

(Continue)

#7

DC-OV

Check main power supply

voltage

Too high or

too low

Turn off power

Reset & start

#8 #36

DC-UV

Power
normal

Internal

components

damage

Contact your

Local Danfoss

Main Failure

Check power

supply voltage

Set 14-11 to

lower value

Reset & start

INTEGRATION INTO SYSTEM

47AB237586440343en-000601

Troubleshooting

Check alarm #

(Continue)

GENERAL INFORMATIONPRODUCT INFORMATIONSYSTEM DESIGNINTEGRATION INTO SYSTEMORDERING INFORMATION

#49

Speed limit (low)

Wrong wiring of U/V/W

Compressor bearing wear

Compressor stopped

Automatic restart

after 30s

10 restarts

before blockage

(20 possible)

#18

Start failed

Minimum speed

not reached

after 2 sec.

Compressor stopped,
similar reason as A49

Automatic restart

after 30s

10 restarts

before blockage

(20 possible)

INTEGRATION INTO SYSTEM

48 AB237586440343en-000601

Dismantal and disposal

Danfoss recommends that compressors and compressor oil should be recycled by a
suitable company at its site.

GENERAL INFORMATIONPRODUCT INFORMATIONSYSTEM DESIGNINTEGRATION INTO SYSTEMORDERING INFORMATION

INTEGRATION INTO SYSTEM

49AB237586440343en-000601

Packaging

Depth

Height

Width

CD303 packaging

Single pack

Compressor single pack

Compressor Industrial pack

GENERAL INFORMATIONPRODUCT INFORMATIONSYSTEM DESIGNINTEGRATION INTO SYSTEMORDERING INFORMATION

Frequency converter single
pack

Compressor model

Height Width Depth Weight

(mm) (inch) (mm) (inch) (mm) (inch) (kg) (lb)

VZH052-VZH065 524 20.6 292 11. 5 286 11. 3 38 84

Compressors are not packed individually but are
shipped all together on one pallet. They can be

Compressor

model

Nbr*

Length Width Height Gross Weight

(mm) (inch) (mm) (inch) (mm) (inch) (kg) (lb)

ordered in quantities of full pallets only, multiples
of 12 compressors, according to below table.

VZH052 12 1170 46.1 815 32.1 650 25.6 540 119 0 3

VZH065 12 1170 46 .1 815 32.1 650 25.6 540 119 0 3

Static

stacking

pallets

IP20 IP55

Drive supply

voltage

Compressor

Height Width Depth Weight Height Width Depth Weight

(mm) (inch) (mm) (inch) (mm) (inch) (kg) (lb) (mm) (inch) (mm) (inch) (mm) (inch) (kg) (lb)

T2: code J VZH052-065 346 13.6 810 31.9 320 12.6 24 53 346 13. 6 810 31.9 320 12.6 28 62

T4: code G

T6: code H

VZH052 349 13.7 500 19. 7 330 13. 0 13 29 346 13.6 810 31.9 320 12.6 24 53

VZH065 349 13 .7 500 19.7 330 13.0 13 29 346 13. 6 810 31.9 320 12.6 24 53

VZH052 349 13.7 500 19. 7 330 13. 0 13 29 346 13.6 810 31.9 320 12.6 24 53

VZH065 346 13. 6 810 31.9 320 12.6 24 53 346 13. 6 810 31.9 320 12.6 28 62

50 AB237586440343en-000601

Ordering codes

Compressor code numbers

Single pack

Compressor

model

VZH052

VZH065

Equipment

version

Single VZH052CGANB/M 120 G0149 VZH052CJANB/M 120G0155 VZH052CHANB/M 120 G0147

Unified VZH052CGDNB/M 120G0265 VZH052CJDNB/M 120G0267 VZH052CHDNB/M 120G0269

Single VZH065CGANB/M 120 G0152 VZH065CJANB/M 120G0153 VZH065CHANB/M 120 G0150

Unified VZH065CGDNB/M 12 0G0271 VZH065CJDNB/M 120G0273 VZH065CHDNB/M 120 G0275

Industrial pack

Danfoss scroll compressors VZH can be ordered
in either industrial packs or in single packs. Drive

380-480V/3ph/50&60Hz

Compressor Name Code no Compressor Name Code no Compressor Name Code no

G

200-240V/3ph/50&60Hz

can be ordered in single packs. Please use the
code numbers from below tables for ordering.

J

525-600V/3ph/50&60Hz

H

GENERAL INFORMATIONPRODUCT INFORMATIONSYSTEM DESIGNINTEGRATION INTO SYSTEMORDERING INFORMATION

Compressor

model

VZH052

VZH065

Equipment

version

Single VZH052CGANB/I 120 G0143 VZH052CJANB/I 120 G0142 VZH052CHANB/I 120G0141

Unified VZH052CGDNB/I 120G0266 VZH052CJDNB/I 12 0G0268 VZH052CHDNB/I 120G0270

Single VZH065CGANB/I 120 G014 6 VZH065CJANB/I 120G0145 VZH065CHANB/I 12 0G014 4

Unified VZH065CGDNB/I 120G0272 VZH065CJDNB/I 120G0274 VZH065CHDNB/I 120G0276

380-480V/3ph/50&60Hz

Compressor Name Code no Compressor Name Code no Compressor Name Code no

G

200-240V/3ph/50&60Hz

J

525-600V/3ph/50&60Hz

H

VZH converter order information

CDS303 Drive

Voltage Compressor Model & power IP class RFI class Drive name sales code

IP20 H2 CDS303P11KT2E20H2 135X3360

200-240V/3ph/50&60Hz

T2

T4

380-480V/3ph/50&60Hz

T6

525-600V/3ph/50&60Hz

Variable speed compressor package VZH065 (voltage code G) + CDS303 (T4, 11kW) is qualified, to be used at drive supply voltage 380-440V (3 phase, 50/60Hz).
Any further information please contact local Danfoss engineers.

VZH052/VZH065 CDS303 11k W

VZH052 CDS303 11k W*

VZH065 C DS30 3 15kW

VZH052 CDS3 03 15k W

VZH065 CDS303 22kW

IP20 H3 CDS303P11KT2E20H3 135X3371

IP55 H2 CDS303P11KT2P55H2 135X3361

IP55 H3 CDS303P11KT2P55H3 135X3372

IP20 H2 CDS303P11KT4E20H2 135X 3298

IP20 H3 CDS303P11K T4E20 H3 135X3373

IP55 H2 CDS303P11KT4P55H2 135X3362

IP55 H3 CDS303P11KT4P55H3 135X3375

IP20 H2 CDS303P15KT4E20H2 135X1998

IP20 H3 CDS303P15KT4E20H3 135X3379

IP55 H2 CDS303P15KT4P55H2 135X3369

IP55 H3 CDS303P15KT4P55H3 135X3380

IP20 HX CDS303P15KT6E20HX 135X3543

IP55 HX CDS303P15KT6P55HX 135X48 63

IP20 HX CDS303P22K T6E20HX 135X3560

IP55 HX CDS303P22KT6P55HX 135X3559

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Accessories

Solder sleeve adapter set

Code n° Description Application Packaging Pack size

120Z0128 Rotolock adaptor set (1-1/4" ~ 7/8") , (1-1/4" ~ 3/4") VZH052-065 Multipack 6

Rotolock nuts and sleeves kit

GENERAL INFORMATIONPRODUCT INFORMATIONSYSTEM DESIGNINTEGRATION INTO SYSTEMORDERING INFORMATION

Code n° Description Application Packaging Pack size

120Z5076 2 rotolock nuts 1"1/4 with sleeves and gaskets VZH052-065 Multipack 6

Rotolock adapter

Code n° Description Application Packaging Pack size

120Z0 367 Adaptor (1-1/4" ~ 7/8") VZH052-065 suction Multipack 10

120Z0 366 Adaptor (1-1/4" ~ 3/4") VZH052-065 discharge Multipack 10

Mounting kits

Code No Description Application Packaging Pack Size

120Z0 622

Mounting kit for 1 scroll compressors including 4 grommets,
4 sleeves, 4 bolts, 4 washers, 2 grounding screws

VZH052-065 Single pack 1

Crankcase heater

Code n° Description Application Packaging Pack size

120Z0 059

120Z0 060

120Z5012 Belt type crankcase heater, 70W, 460V, CE mark, UL VZH052-065 Multipack 6

120Z5013 Belt type crankcase heater, 70 W, 575V, CE mark, UL VZH052-065 Multipack 6

Belt type crankcase heater, 65 W, 230V, CE mark, UL (Wire
length: 1000 mm)

Belt type crankcase heater, 65 W, 400 V, CE mark, UL (Wire
length: 1000 mm)

VZH052-065 Multipack 6

VZH052-065 Multipack 6

Discharge thermostat kit

Code n° Description Application Packaging Pack size

7750009 Discharge thermostat kit VZH052-065 Multipack 10

ORDERING INFORMATION

7973008 Discharge thermostat kit VZH052-065 Industry pack 50

52 AB237586440343en-000601

Accessories

Lubricant

Code n° Description Application Packaging Pack size

120Z50 34 PVE lubricant, 1 litre can 320HV (FVC68D) VZH052-065 Multipack 12

Acoustic hoods

Code No Description Application Packaging Pack Size

120Z50 84 Acoustic hood for scroll compressor VZH052-065 Single pack 1

Terminal box

GENERAL INFORMATIONPRODUCT INFORMATIONSYSTEM DESIGNINTEGRATION INTO SYSTEMORDERING INFORMATION

Code No Description Application Packaging Pack Size

120Z5018 Square terminal box VZH052-065 Multipack 10

Oil level switch

Typ e Code n° Description Application Packaging Pack size

120Z0 560 Oil level switch screw in- mechanical part All models Single pack 1
120Z0 561 Oil level switch - electrical part (24V AC/DC) All models Single pack 1
120Z0 562 Oil level switch - electrical part (230V AC) All models Single pack 1

Spare parts frequency converter

LCP ’s

Code n° Description Application Packaging Pack size

120Z0 326 LCP display Frequency converter / all models Single pack 1

175Z0929 RS cable to LCP Frequency converter / all models Single pack 1

130 B0264 LCP cradle, required to mount the LCP on IP55 casings Frequency converter / all models Single pack 1

ORDERING INFORMATION

53AB237586440343en-000601

Danfoss Commercial Compressors

Danfoss Inverter Scrolls

is a worldwide manufacturer of compressors and condensing units for refrigeration and HVAC applications. With a wide range
of high quality and innovative products we help your company to find the best possible energy efficient solution that respects
the environment and reduces total life cycle costs.

We have 40 years of experience within the 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 spanning across three continents.

Danfoss Turbocor Compressors

Danfoss Scrolls

Danfoss Optyma Condensing Units

Danfoss Maneurop Reciprocating Compressors

Danfoss Light Commercial Refrigeration

Compressors

Our products can be found in a variety of applications such as rooftops, chillers, residential air conditioners,
heatpumps, coldrooms, supermarkets, milk tank cooling and industrial cooling processes.

http://cc.danfoss.com

Danfoss Commercial Compressors, BP 331, 01603 Trévoux Cedex, France | [phone]

AB237586440343en-000601

© Danfoss | DCS (CC) | 2019.10