schroff 60714-050 User manual

VARISTAR LHX 20
User’s Manual
Product Number:
60714-050
Revision: R2.1, May 10, 2012
Doc-No: 60130-531

Impressum:
Schroff GmbH
D-75334 Straubenhardt, Germany
The details in this manual have been carefully compiled and
checked - supported by certified Quality Management System
to EN ISO 9001/2000
The company cannot accept any liability for errors or misprints.
The company reserves the right to amendments of technical
specifications due to further development and improvement of
products.
Copyright2012
All rights and technical modifications reserved.
Rev. Date updated Change
R1.0 September 09, 2008 Initial release
R2.0 November 11, 2008 Initial release
R2.1 May 10, 2012 Table 1 Requirements for water quality updated

VARISTAR LHX 20
Cooling module 60714-050
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Table of Contents
1 Safety Information ............................................................................................ 1
1.1 Intended Use ....................................................................................................... 1
1.2 Manufacturer's Safety Information ....................................................................... 1
1.2.1 Liability Disclaimer ................................................................................. 1
1.2.2 Safety symbols used in this manual....................................................... 1
1.3 Safety Information for the Operator ..................................................................... 2
1.4 Additional literature .............................................................................................. 2
2 Device description............................................................................................ 3
2.1 Overview of Cooling Module................................................................................ 4
2.2 How the cooling system works ............................................................................ 5
2.3 Air loop................................................................................................................. 6
2.4 Water loop ........................................................................................................... 6
2.5 Regulation............................................................................................................ 7
2.6 Alarms.................................................................................................................. 7
3 Operating the cooling module......................................................................... 8
3.1 Control and display unit ....................................................................................... 8
3.2 Setting the air exit temperature............................................................................ 9
4 Storage and transport .................................................................................... 10
4.1 Removing the packaging materials.................................................................... 10
5 Commissioning............................................................................................... 11
5.1 Setting up the VARISTAR cabinet ..................................................................... 11
5.2 Initial Commissioning......................................................................................... 11
5.3 Connect to the cooling water source ................................................................. 12
5.3.1 Requirements for water quality ............................................................ 13
5.3.2 Water connections at the cooling module............................................ 14
5.4 Connecting to the electricity supply ................................................................... 15
5.5 Bleeding air from the cooling system................................................................. 16
5.5.1 Steps for bleeding................................................................................ 17
5.5.2 Test operation...................................................................................... 18
6 Interfaces......................................................................................................... 19
6.1 Pinout of D-sub 25 socket.................................................................................. 19
6.2 Inputs and outputs on the control board ............................................................ 20
6.3 Pinout of D-sub 9 socket.................................................................................... 20
6.4 RJ45 socket pinout ............................................................................................ 20

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7 Maintenance and Repair ................................................................................ 21
7.1 Inspection and Maintenance Intervals ............................................................... 21
7.2 Error messages ................................................................................................. 22
7.3 Fitting/removing the cooling module .................................................................. 23
7.3.1 Decommissioning the cooling module ................................................. 23
7.3.2 Fitting and removing the cooling module ............................................. 24
7.3.3 Flushing the cooling module with antifreeze........................................ 25
7.4 Component replacement ................................................................................... 26
7.4.1 Removing and fitting fans .................................................................... 26
7.4.2 Removing and fitting the fan unit ......................................................... 27
7.4.3 Cleaning / replacing the droplet separator........................................... 28
7.4.4 Replacing the electric control valve actuator ....................................... 29
7.4.5 Replacing the control and display unit ................................................. 30
7.4.6 Replacing the temperature sensors..................................................... 31
7.4.7 Replacing other components ............................................................... 32
8 Service ............................................................................................................. 33
8.1 Service and Returns .......................................................................................... 33
8.2 Technical support .............................................................................................. 33
8.3 Declaration of Conformity .................................................................................. 34
8.4 Accessories ....................................................................................................... 35
8.5 Spare parts ........................................................................................................ 35
9 Technical data................................................................................................. 36
10 Appendix ......................................................................................................... 37
10.1 Cooling capacity ................................................................................................ 37
10.2 Connectors/interfaces on the control board....................................................... 38
10.3 AC power supply diagram.................................................................................. 39
10.4 Temperature sensor connections ...................................................................... 40
10.5 Fan and control valve connections .................................................................... 41
10.6 Display connection; connectors on the control board ........................................ 42
10.7 Dimensions ........................................................................................................ 43
10.8 LHX 20 base plate ............................................................................................. 44
10.9 Example installation........................................................................................... 45
10.10 Piping and instrumentation diagram .................................................................. 46

VARISTAR LHX 20 Safety Information
Cooling module 60714-050
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1 Safety Information
1.1 Intended Use
The 60714-050 cooling module described in this manual is a component of a
Schroff VARISTAR LHX 20 cabinet. The VARISTAR LHX 20 cabinet forms a
closed system and allows the cooling of electronic components mounted in its
19" plane independently of the ambient or room temperature. Before
commencing operation the module must be connected to an external
recirculation cooling system (reciprocator chiller).
1.2 Manufacturer's Safety Information
1.2.1 Liability Disclaimer
Schroff accepts no liability for any errors in this documentation. To the maximum
extent permissible by law, any liability for damage, direct or indirect, arising from
the supply or use of this documentation is excluded.
Schroff retains the right to modify this document, including the liability
disclaimer, at any time without notice and accepts no liability for any
consequences of such alterations.
1.2.2 Safety symbols used in this manual
Hazardous voltage!
This symbol warns of hazardous voltage. Before commencing work on live
sections of the equipment you should familiarise yourself with the dangers of
high voltages and with the normal accident-prevention procedures.
Attention!
This symbol warns of danger. It indicates that you are in a situation that could
be injurious to health. Before commencing work you should familiarise yourself
with the normal accident-prevention procedures.
Static discharge hazard!
Static electricity can damage sensitive components in the system. 
To avoid such damage you should wear ESD armbands or maintain frequent
bodily contact with a part of the metal enclosure.
Danger of tipping over!
The asymmetrical positioning of the cooling module poses a risk of the cabinet
tipping over. The VARISTAR LHX 20 must always be adequately secured

during transport.

VARISTAR LHX 20 Safety Information
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1.3 Safety Information for the Operator
Commissioning, maintenance and operation of the system may only be carried
out by suitably trained technical personnel. The nationally applicable health and
safety regulations must also be adhered to.
1.4 Additional literature
You can find further information on the VARISTAR LHX 20 online at
www.varistar.co.uk

VARISTAR LHX 20 Device description
Cooling module 60714-050
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2 Device description
The 60714-050 cooling module is a component of a Schroff VARISTAR LHX 20
cabinet. The module is a plug-in unit that may be fitted to the left or right in the
cabinet according to the customer's wishes.
The cooling module has a maximum cooling output of 20 kW and is designed for
a mains supply voltage of 230 VAC (115 VAC and 48 VDC versions are available
on request).
The supply voltage is converted to 48 VDC by an adaptor to power the control
electronics and the fans.
Since the control electronics and fans are designed for a 48 VDC supply, the
cooling module also finds application in telecommunications environments.
Further information is available on request.
ServicePLUS
For further information visit: www.schroff.biz/ServicePlus
This cooling module is finished in RAL 7021 (black grey) as standard. 
It is shown in red in these instructions for greater clarity of viewing.

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2.1 Overview of Cooling Module
Figure 1: Overview of Cooling Module
1Fans 9Condensation vessel
2Display and control unit 10 Control valve with servo actuator
3Control system 11 AC adaptor
4Mains input IEC320-C14
5Cooling water inlet and return and
condensate drain
6Bleeder valve F1/F2 Air outlet temperature sensors
7Droplet separator F3/F4 Air inlet temperature sensors
8Air/water heat exchanger F5 Water inlet temperature sensor

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2.2 How the cooling system works
The cooling system consists of an air loop and a water loop.
The fans of the cooling unit draw warm air from the rear section of the cabinet
and into an air/water heat exchanger. The air is cooled here and then blown into
the front area of the cabinet. 
Inside the air/water heat exchanger the heat energy of the warm air is
transferred to the medium of water. The air/water heat exchanger is connected
to an external reciprocal chiller unit (not supplied with the module), where the
water is cooled again.
Figure 2: Functioning of the cooling module
1Cooling module 3Chiller
2LHX 20 cabinet

VARISTAR LHX 20 Device description
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2.3 Air loop
The heat generated by the electronic components housed in the 19" plane
collects in the rear section of the cabinet. The fans of the cooling module draw
the heated air away and feed it into the air/water heat exchanger. The heat
energy is thus transferred to the water loop. The cooled air is then returned to
the front section of the cabinet.
A droplet separator draws off any condensation that may form. 
The condensation is collected in a condensation vessel and discharged via the
condensate drain at the front of the LHX 20 module.
The use of 6 fans, positioned vertically over the entire cabinet height, ensures
that a homogenous temperature gradation is obtained. The temperature
difference may thus be reduced and the efficiency of the cooling system
increased.
Air loop components:
• Air/water heat exchanger
• Droplet separator
• Fans
• Air temperature sensors
2.4 Water loop
Cooling water from the external chiller passes through the air/water heat
exchanger of the cooling module, absorbs heat from this and returns to the
chiller. Temperature control is obtained via a servo-driven control valve that
regulates the water flow rate according to the cooling capacity required.
Please see the piping and instrumentation diagram in the Appendix for further
information.
Water loop components:
• Control valve
• Air/water heat exchanger
• Water temperature sensors
Note: The control valve is in fact a three-way valve that functions as a straight-
way valve since the bypass has been factory sealed. If required, the cover seal
can be removed by Schroff Service to provide three-way functionality.

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2.5 Regulation
The fans and the control valve of the water loop are governed by a
microprocessor-controlled control unit. 
A PID control loop regulates the water flow rate through the air/water heat
exchanger on the basis of the air exit temperature from the cooling module.
To compensate for temperature gradation effects, the air exit temperature is
obtained using two temperature sensors (F1/F2) set at different heights. The
average of their values is used as the control value for opening and closing the
control valve.
The fans are driven constantly at 80% of nominal speed to ensure sufficient air
circulation in the cabinet. Should the air exit temperature exceed 26° C (factory
setting), the unit switches to maximum cooling capacity: the control valve is
opened to 100% and the fans are driven at 100% nominal speed.
The control characteristic has been factory preset but can be altered and
adapted by Schroff Service or one of its licensed service partners.
2.6 Alarms
The control electronics can detect various faults (e.g. a broken sensor cable or
a temperature that exceeds set limit values), save them in an alarm memory and
signal the fault on the display or via potential-free contacts. A buzzer (horn) is
fitted in the cooling module for issuing acoustic alarms.
The following situations are signalled:
• Fan speed falls below minimum permitted speed
• Fan failure
• Limit (min/max) value of a temperature sensor reached
• Broken cable on a temperature sensor
• Door open (optional)
• Operating at max. cooling output

VARISTAR LHX 20 Operating the cooling module
Cooling module 60714-050
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3 Operating the cooling module
3.1 Control and display unit
The combined control and display unit allows various settings and adjustments
to be made. In normal operation the display shows the current air exit
temperature from the module (F1/F2 averaged).
Figure 3: Display and control unit
UP button Pressing this button increases the value of a
parameter.
DOWN button Pressing this button reduces the value of a 
parameter.
If an alarm has been activated, this button switches
off the buzzer function (horn).
SET button Pressing the SET button during normal operation
displays the current set value of the air exit 
temperature. Now pressing the UP button will
increase the set value; pressing the DOWN button
will reduce the set value.
FUNCTION button Pressing this button displays the air entry 
temperature (average values of sensors F3/F4) .
STANDBY button This button switches the cooling unit on or puts it into
standby mode.
Please note: When the unit is in standby mode, all
components are still electrically live.

VARISTAR LHX 20 Operating the cooling module
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3.2 Setting the air exit temperature
The user can set the air exit temperature of the cooling module within the range
18° C to 30° C.
To do so, follow the following steps:
1 Press and hold the SET button. The current set value of the air exit
temperature is displayed.
2 While holding down the SET button, use the UP or DOWN button to obtain
the desired new set value.
3 Release the SET button to accept the new set value.
The user cannot make any other adjustments than the air exit temperature.
Modifications to the parameterisation or control behaviour of the alarm outputs
can be carried out only by Schroff service personnel or authorised Schroff
service partners.

VARISTAR LHX 20 Storage and transport
Cooling module 60714-050
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4 Storage and transport
For ease of transport the cooling module can be removed and transported
separately from the cabinet. You should pay attention to the relevant work
instructions and safety information.
It is essential that the VARISTAR LHX 20 and/or cooling module are free of any
water during transport. (See Chapter 7.3.1, "Decommissioning the cooling
module")
4.1 Removing the packaging materials
The VARISTAR LHX 20 is delivered on a special pallet. After unpacking, check
the cabinet and cooling module for any damage caused during transport or
otherwise.
Danger of tipping over!
The asymmetrical positioning of the cooling module poses a risk of the cabinet
tipping over. The VARISTAR LHX 20 must always be adequately secured

during transport.
Attention!
If the unit is to be stored or transported in ambient temperatures below 0 °C,
special measures must be taken to prevent frost damage.


(See Chapter 7.3.3, "Flushing the cooling module with antifreeze")
Attention!
Risk of condensation forming.
After storage at temperatures below 10 °C, sufficient acclimatisation time must
be allowed before the unit is switched on.

VARISTAR LHX 20 Commissioning
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5 Commissioning
5.1 Setting up the VARISTAR cabinet
5.2 Initial Commissioning
Before commissioning the cooling module the following work must be carried
out:
• Connect to cooling water source.
• Connect to supply voltage.
• Bleed (exhaust any trapped air from) the cooling module.
Danger of tipping over!
The asymmetrical positioning of the cooling module poses a risk of the cabinet
tipping over. The VARISTAR LHX 20 must always be adequately secured

during transport.
Attention!
The setting up, commissioning, completion, maintenance and repair of 
VARISTAR cabinets may only be carried out by suitably trained technical 
personnel. 
During all such operations the nationally applicable health and safety 
regulations must be adhered to.
ServicePLUS
The setting up, commissioning, completion, maintenance and repair of 
VARISTAR cabinets may also be carried out within Schroff's service program.
Please ask about our after-sales services.
You can obtain further information about our ServicePLUS options online at:
www.schroff.biz/ServicePlus
Hazardous voltage!
Under certain circumstances during commissioning, completion, maintenance
and service it is necessary to open the enclosure.

Some exposed parts may be under live voltage. These works must therefore
only be carried out by specially trained technical personnel.

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5.3 Connect to the cooling water source
Attention!
Connection to the cooling water supply may only be carried out by a 
refrigeration engineer or suitably trained plumber.
Notes on the water connection:
The cooling infrastructure to which the unit is connected (the external water
loop) must be appropriately dimensioned by the system designer, taking into
consideration the available pump pressure and type, the nominal pipe diame-
ters and the pressure loss expected in the load circuit (the cooling module).
The water pipes used may be either flexible or rigid types. The behaviour of the
materials used in the module with those of the external loop should be

observed for any adverse reaction in order to avoid corrosion damage.
During construction of the external pipe circuitry care should be taken to pre-
vent contaminants entering the system; the pipes should be flushed clean prior
to connection to the cooling module.
It is recommended that isolation and drainage valves be provided for each cab-
inet or cooling module, together with a central water filter and air separator.
The control valve in the water loop of the cooling module is a three-way valve
that is supplied configured as a straight-way (two-way) valve; the bypass is
sealed closed. The advantage of this solution is that only the specific volume of
water required for cooling flows through the air/water heat exchanger.

The circulator pump can thus be operated with constant pressure and variable
water flow.
For cooling systems in which the three-way functionality is required, the 
two-way valve can be suitably modified by Schroff service personnel.

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5.3.1 Requirements for water quality
Table 1: Requirements for water quality
Attention!
For problem-free operation of the cooling module, the following water quality
requirements must be satisfied:

(see also VDI 3803)
Electrical conductivity: 25 mS/m - 220 mS/m at 25 °C
Hydrogen concentration: 7.5 - 8.5 (pH value) at 20 °C
Chloride: < 200 g/m³
Total hardness: > 3 °dH < 8 °dH
Colony-forming units: < 10 000 CFU/ml
Appearance: clear, without sediment
Colour: colourless
Attention!
To prevent electrochemical corrosion the compatibility of the materials used in
the cooling module with those of the external cooling circuit should be

monitored and where necessary a suitable anti-corrosion agent applied.
Risk of corrosion is particularly high where aluminium is used in the external
water loop.
The following materials are used within the cooling module:
•copper
•brass
•stainless steel
• cast iron

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5.3.2 Water connections at the cooling module
The water connections are situated to the front of the cooling module. The pipes
are fed through the base of the cabinet.
Please consult the drawing provided in the Appendix of this manual for the
nominal pipe diameters and position of the connections in the cabinet.
Connect the water inlet (2), water return (1) and condensate drain (3) to the
cooling module as shown in the illustration below.
Figure 4: Water connections at the cooling module
Attention!
Ensure that the condensate drain is provided with sufficient downward 
gradient to the waste water system.
1Water return 3Condensate drain
2Water inlet

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5.4 Connecting to the electricity supply
Mains supply to the 230 VAC version is via a IEC320-C14 connector with cable
strain relief, situated on the bottom of the cooling module.
A suitable connecting cable (IEC320-C13 Schuko) is provided with the module.
All cooling modules must be protected by an external pre-fuse of
max. 10 A.
Hazardous voltage!
Under certain circumstances during commissioning, completion, maintenance
and service it is necessary to open the enclosure.

Some exposed parts may be under live voltage. These works must therefore
only be carried out by specially trained technical personnel.
Always disconnect the supply voltage before opening the module!
These cooling modules are designed for a 230 VAC mains supply. 
The control electronics and fans, however, operate from a 48 VDC supply. The
230 VAC version is fitted with a 230 VAC mains adaptor,

which is positioned in the cooling module beneath the heat exchanger. 
If the cooling unit is to be used exclusively in telecommunications environments 
(redundant -48 VDC power supply), please contact Schroff Service for further
information.
Attention!
If the connecting cable supplied is not suitable for your country, you should
only substitute a mains connector with protective earthing that is permitted for
your device and for use in your country.
Hazardous voltage!
When power is connected, the cooling module enters standby mode. Certain
parts inside the unit are however already live.
Always disconnect the supply voltage before opening the module!
When power is connected to the module the display shows "OFF".If this does
not occur, open the cover of the display unit and check the status of the circuit
breaker situated below.

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5.5 Bleeding air from the cooling system
Requirements for bleeding the system:
• The water installation must be fully completed. Water inlet to the module
should however still be closed.
• The electrical installation must be completed.
• The refrigeration engineer or plumber with access to the water installation
should be present.
To bleed air from the cooling system the control valve must be open. 
The control valve is driven by a servo actuator 
and opened and closed by the control electronics according to the demand for
cooling.
The control valve is only open when:
• the supply voltage is present,
• the cooling module is switched on,
• and the ambient temperature is over 18 °C.
At temperatures below 18 °C and without power the valve is closed and bleed-
ing cannot take place.
For safety reasons Schroff recommends that during bleeding operations
the power supply be isolated and the control valve opened by operating
the actuator manually.
If the equipment consists of multiple VARISTAR cabinets with cooling modules,
all systems are bled together.