to which this declaration relates is in conformity with the following standard(s) or other normative
document(s)
EN1012-2:1996+A1:2009 Compressors and Vacuum Pumps - Safety Requirements – Part 2
EN61010-1:2010 Safety Requirements for Electrical Equipment for Measurement,
EN61326-1:2013 Electrical equipment for measurement, control and laboratory Use.
(Class A Emissions,EMC requirements. General requirements
Industrial Immunity)
EN50581:2012 Technical Documentation for the Assessment of Electrical and
Products with respect to the Restriction of Hazardous Substances
EN13463-1:2009 Non-electrical equipment for use in potentially explosive
EN13463-5:2011 Non-electrical equipment for use in potentially explosive
CAN/CSA-C22.2 No.61010.1-04 Safety Requirements for electrical equipment for Measurement,
Control and Laboratory Use, Part 1: General requirements
UL61010-1, 2nd Edition Safety Requirements for electrical equipment for Measurement,
Control and Laboratory Use, Part 1: General requirements
and fulfils all the relevant provisions of
2006/42/EC Machinery Directive
2014/35/EU Low Voltage Directive
2014/30/EU Electromagnetic Compatibility (EMC) Directive
2014/34/EU ATEX Directive on use in Potentially Explosive Atmospheres
II 3 G c IIB T4 Internal Atmospheres Only, Tech File ref MPTR 0271
2011/65/EU Restriction of Certain Hazardous Substances (RoHS) Directive
Note: This declaration covers all product serial numbers from the date this Declaration was signed
onwards.
10.08.2015, Burgess Hill
Mr Peter Meares
Senior Technical Support Manager, General Vacuum
This product has been manufactured under a quality management system certified to ISO 9001:2008
Vacuum Pumps
Control and Laboratory Use. General Requirements
Electronic
atmospheres. Basic method and requirements
atmospheres. Protection by constructional safety ‘c’
Date and Place
P200-06-720 Issue D
P200-10-019
Product
Product Label
Meaning
20
20
This product cont ain s h azardous substance s in at least one of the
Pump Type
Pump Size
RV Pumps
RV3,5,8,12, E Lab, nRVi
EM Small Pumps
E2M0.7, 1.5, E1M18, E2M18, 28, 30, nE2M40i
nEXT Pumps
nEXT 85, 240, 300, 400, Splitflow
nXDS pumps
nXDS 6, 10, 15, 20
EXT pumps
EXT75DX
XDS pumps
XDS35, 46, 100
Diaphragm
XDD 1, D lab
Turbo Pump Carts
T station, nEXT station
Cast Aluminium
Brass pipe Fittings
Recyclable Natural Wood
Recyclable Cardboard
Recyclable Polypropylene
Recyclable Mild Steel
Issue C
Material Declaration
In accordance with the requirements of the Chinese regulatory requirement on the Management Methods for the
Restriction of the Use of Hazardous Substances in Electrical and Electronic Products Order No. 32 (also known as
‘China RoHS2’) an d SJ/T 11364 Mark ing for t he Re stricte d Use of Hazardo us Subst ances i n Elec tronic and Electr ical
Products:
Product Labels
All pumps in the
list below
部件名称
Part name
铸铝
铜管管件
homogeneous materials used which are above the limit requireme n t
in GB/T 26572 as detailed in the declarat ion table below.
These parts can safe ly b e used for the environmental protection use
period as indicated.
O: Indicates th at the hazardous sub stance contained in all of the hom ogeneous materials for this part is b elow
the limit requirement in GB/T 26572.
X:表示该有害物质在该部件的至少一种均质材料中的含量超出 GB/T26572 标准规定的限量要求。
X: Indicates that the hazardous substance contain ed in at least one of the h omogeneous materials used for
this part is above th e l imit requirement of GB/T26572.
NOTES: These products are E U RoHS compliant, the foll owing Exemptions apply:
6(b) Lead as an alloying elemen t in aluminiu m containing up to 0.4% by weight.
6(c) Copper alloy containing up to 4% lead by weight
X O O O O O
Packaging Informat ion
Pallet Over-shipper Protection Pieces Support Braces
Edwards and the Edwards logo are trademarks of Edwards Limited.
A735-01-880 Issue C
CAUTION
WARNING
1Introduction
1.1Scope of this manual
This manual provides installation, operation and maintenance instructions for the Edwards nXDS series of scroll
pump. The pump must be used as specified in this manual. Read this manual before installing and operating the
pump.
Important safety information is highlighted as WARNING and CAUTION instructions; these instructions must be
obeyed. The use of WARNINGS and CAUTIONS is defined below.
Warnings are given where failure to observe the instruction could result in injury or death to
people.
Cautions are given where failure to observe the instruction could result in damage to the equipment, associated
equipment and process.
Introduction
Pressures are stated as absolute pressures unless otherwise stated.
The following warning labels are on the pump:
This equipment is designed to meet the requirements of Group II Category 3 equipment in accordance with Directive
94/9/EC of the European Parliament and the Council of 23rd March 1994 on the approximation of the laws of the
Member States concerning equipment and protective systems intended for use in potentially explosive atmospheres.
(The ATEX Directive).
The ATEX Category 3 applies in respect of potential ignition sources internal to the equipment. An ATEX Category has
not been assigned in respect of potential ignition sources on the outside of the equipment as the equipment has not
been designed for use where there is an external potentially explosive atmosphere.
There is no potential source of ignition within the pump during normal operation but there may be potential sources
of ignition under conditions of foreseeable and rare malfunction as defined in the Directive. Accordingly, although
the pump is designed to pump flammable materials and mixtures, operating pr ocedures should ensure that under all
normal and reasonably foreseeable conditions, these materials and mixtures are not wi thin explosive limits.
Category 3 is considered appropriate for the avoidance of ignition in the case of a rare malfunction which allows
flammable materials or mixtures to pass through the pump whilst within their explosive limits.
When flammable materials are present within the equipment:
Do not allow air to enter the equipment.
Ensure the system is leak tight.
Further details can be obtained by contacting Edwards. Refer to the address page at the back of this instruction
manual.
1.3General description
The nXDS pump is shown in Figure 1.
The nXDS pump is a truly dry vacuum pump as all the bearings, with their hydrocarbon lubricant, are isolated from
the vacuum space. The nXDS pump is suitable for use on vapour handling processes, and may be used for some
pumping applications involving corrosive substances. For information on pump ing flammable gases, contact Edwards.
The body of the pump includes a fixed scroll and an orbiting scroll. The orbiting scroll is controlled by an electric
motor through an eccentric cam on the motor drive shaft. The movement of the orbiting scroll, meshed with the
fixed scroll, forms successive crescent shaped volumes in the pump. Gas that enters the pump through the inlet is
compressed by the movement of the orbiting scroll and swept towards the centre of the fixed scroll. The compressed
gas enters the exhaust port near the centre of the fixed scroll and is exhausted from the pump through the outlet.
Refer to Section 2.1 for details of operating conditions.
1.4Pump controller
The integral pump controller manages the supply of current to a three-phase electric motor in accordance with
operating conditions. The controller monitors power and temperature, and will protect the pump in the event of
operation under sustained high load or under fault conditions.
The controller provides the user interface (refer to Figure 1). The pump may be operated in these modes:
Manually, using the buttons on the interface panel. Refer to Figures 2 and 9.
Remotely via serial communications or d igital and analogue process control (parallel), via the 15-way D-type
Edwards and the Edwards logo are trademarks of Edwards Limited.
Figure 1 - nXDS scroll pump
1. Lifting eye
2. NW25 inlet port
3. Gas ballast control
4. Cooling fan
5. NW25 exhaust port
6. Rubber feet
7. 15-way D-type connector
8. USB port (service mode only)
9. User interface panel
10.Mains power connector
11.Secondary earth bond point
A735-01-880 Issue C
Introduction
1.5Logic interface
The pump controller can be operated via the 15-way D-type logic interface connector. The signals on the logic
interface are of the following types:
Control inputs: these are switch-type and analogue signals that are used to control the pump
Status outputs: these outputs identify the status of the system Tab
The logic interface has been designed to support both serial contro l, parallel control and monitoring, operating
though one connector. For serial control either RS232 or RS485 can be selected.
For Control Modes refer to Table 1.
For Logic interface data refer to Section 2.5.
To pump high vapour loads, gas ballast can be delivered into the pump to prevent condensati on of the vapour carried
by the pumped gases.
Air can be introduced to the low vacuum stages through the gas ballast control (Figure 1, item 3). Alternatively, an
inert gas such as nitrogen can be supplied through a suitable external valve and by using the appropriate adaptor,
available as an accessory. Refer to Section 7.
Edwards and the Edwards logo are trademarks of Edwards Limited.
A735-01-880 Issue C
WARNING
2Technical data
If the nXDS pump is operated outside the specified limits, the pump housing may become hot.
2.1Operating and storage conditions
Table 2 - Operating and storage conditions
Operating and storage conditionsnXDS
Ambient temperature range (storage)–30 °C to +70 °C
Ambient temperature range (operation)+5 °C to +40 °C
Maximum humidity (storage in original packaging)≤ 95% RH
Maximum humidity (operation)90% RH
Table 3 - Environmental conditions
Environmental conditions
PollutionPollution degree 2
InstallationInstallation category II
Altitude restrictionMax 3000 m
Area of useIndoor
Technical data
2.2Performance
2.2.1General
Table 4 - General characteristics
DescriptionnXDS6inXDS10inXDS15inXDS20i
3h-1
Peak pumping speed (m
Maximum permitted continuous inlet pressure (mbar)
Maximum permitted exhaust pressure (bar gauge)
Maximum permitted gas ballast inlet pressure (bar gauge)0.50.50.50.5
Maximum recommended chamber volume to pump down
from atmospheric pressure (litres)
Maximum pressure rise when stopped, with no inlet or gas
ballast flow (mbar)
Leak tightness (mbar ls
*
These pumps are designed to pump down from atmospheric pressure, but prolonged operation at inlet
pressures higher than specified may reduce bearing life.
†
These pumps are intended to exhaust to atmospheric pressure. High exhaust pressure may reduce tip-seal
life.
‡
Larger volumes may be pumped, but prolonged operation at inlet pressures higher than specified may
reduce bearing life. The nXDS20i is optimised for constant throughput and is not recommended for cyclic
duty.
)6.211.415.122.0
*
†
‡
-1
)1 x 10
20020020050
1111
25507575
7777
-6
1 x 10
-6
1 x 10
-6
1 x 10
-6
Note:If the pump is operated outside the specified limits, then the pump housing may become hot; the controller
may reduce the motor speed; and tip seal wear rate will be increased.
Do not use the nXDS pump to pump pyrophoric or explosive gas mixtures.
The pump is designed to pump the following gases:
Air
Carbon dioxide
Helium
Carbon monoxide
Nitrogen
Argon
Oxygen (O
)
2
The pump can be used to pump water vapour. Caution must be taken to ensure that vapour does not condense inside
the pump. Refer to Section 4.6.1 on how to prevent condensation of water vapour in the pump.
If pumping a vapour or gas no t in the list above, contact Edwards for advice.
2.2.3Performance characteristics
The position of the gas ballast control defines the performance characteristics of the pump. These performance
characteristics are listed in Table 5.
Table 5 - Performance characteristics
DescriptionnXDS6inXDS10inXDS15inXDS20i
Pump ultimate
(mbar)
Gas ballast flow
(l min-1)
Gas ballast position 02 x10
Gas ballast position 15 x 10
Edwards and the Edwards logo are trademarks of Edwards Limited.
2.3Mechanical data
2.3.1General
A735-01-880 Issue C
Technical data
ParameternXDS
Overall dimensions (L x W x H)432 x 282 x 302 mm
Maximum tilt angle10 degrees
Nominal rotational speed1800 rpm (30 Hz)
Mass (maximum)6i - 26.2 kg
Inlet connectionNW25
Outlet connectionNW25
Table 6 - General mechanical data
10i - 25.8 kg
15i - 25.2 kg
20i - 25.6 kg
2.3.2Sound and vibration data
ParameternXDS
Sound pressure, measured at ultimate vacuum 1 metre from the end of the pump
to ISO 3744
Vibration: measured at the inlet port (ISO 3744)Class 1C…< 4.5 mms
Table 7 - Sound and vibration data
52.0 dB (A) ± 2.5
Declared dual number noise
emission values according
with ISO 4871
radial)
–1
(rms
2.3.3Construction
All surfaces of the pump which are exposed to the pumped gases are free from copper, zinc an d cad miu m. E xpo se d
components include: anodised aluminium scrolls, aluminium housing, nickel-plated inlet and exhaust ports, PTFE
composite tip-seals, various stainless steel parts and fluorocarbon elastomer seals.
Other materials of construction include steel, copper, hydrocarbon lubricant and chemically resistant polymers.
2.4Electrical data
Table 8 - Electrical ratings for continuous operation
PumpSupply (Vac rms)PhaseFrequency (Hz)Input current (A rms)
The pumps have a 15-way D-type logic interface connector located on the user interface panel (Figure 1, item 7).
The logic interface connector can be plugged directly into the Edwards 200W Turbo Instrument Controller (TIC) or
turbo controller, or Turbo and Active Gauge controller (TAG). A suitable connector mating half must be used (not
supplied) to connect the nXDS pump to the customer control system. Refer to Table 10 for the interface technical
data and Table 11 for the logic interface pins for the electrical connections.
Table 10 - Logic interface technical data
Logic interface description
Connector
Start, serial enable and remote enable:
Standby control input:
Analogue and RS485 enable control inputs:
Analogue speed input
Voltage accuracy± 5% full scale
NORMAL status output:
FAIL status output:
Analogue 10 V reference
Voltage accuracy± 2% full scale
Output current≤ 5 mA for specified accuracy
*
Mating half of connector not supplied
*
Enable control voltage: low (closed)0 to 0.8 V d.c. (l
Disable control voltage: high (open)4 to 26.4 V d.c. (Internal pull up to 6.4 V nominal)
Enable control voltage: low (closed)0 to 0.8 V d.c. (l
Disable control voltage: high (open)4 to 26.4 V d.c. (Internal pull up to 3.2 V nominal)
Enable control voltage: low (closed)0 to 0.8 V d.c. (l
Disable control voltage: high (open)4 to 52.8 V d.c. (Internal pull up to 6.4 V nominal)
TypeOpen collector transistor plus pull up resistor.
< Normal speed (default 80%)OFF (4.7 k pull up + diode to 12 V d.c.)
≥ Normal speedON (< 0.8 V d.c. sinking 10 mA)
Maximum current rating10 mA
Maximum voltage rating28.8 V d.c.
TypeOpen collector transistor plus pull up resistor.
FailOFF (4.7 k pull up + diode to 12 V d.c.)
OKON (< 0.8 V d.c. sinking 10 mA)
Maximum current rating10 mA
Maximum voltage rating28.8 V d.c.
15-way D-type (male)
= 0.55 mA nominal)
OUT
= 0.3 mA nominal)
OUT
= 0.55 mA nominal)
OUT
0 to 10 V d.c. directly proportional to the motor speed
e.g. 0 V = 0 Hz, 10 V = 30 Hz
+ 10 V d.c. analogue voltage reference
Unipolar output with diode protection
Edwards and the Edwards logo are trademarks of Edwards Limited.
A735-01-880 Issue C
Table 11 - Logic interface connector pins
Pin Number SignalPolarity Use
1Analogue Speed Enable-
control Input
20 V Control Reference-0 V reference for ALL control and status signals listed within
3START / STOP – Control
Input
4STANDBY – Control Input /
Serial-RX / RS-485 A-
5Serial Enable – Control
Input
6RS-232 / RS-485 – Control
Input
7FAIL – Status Output /
Serial-TX / RS-485 B+
80 V Control Reference-0 V reference for ALL control and status signals listed within
9Analogue Speed – Control
Input
10Chassis / Screen-Screen
11+10 V Analogue Reference
– Control Output
12Chassis / Screen-Screen
13Not Connected-Unused control pin.
14REMOTE – Control Input-Connect to Pin 2 (0 V) to enable remote control via Parallel or
15NORMAL – Status output-Logic LOW when the pump rotational speed is at normal
-Connect to Pin 2 (0 V) to enable analogue speed control via
Pin 9.
this table.
-Connect to Pin 2 (0 V) to START the nXDS pump system.
-Connect to Pin 2 (0 V) to enable STANDBY speed when the
SERIAL ENABLE control input is inactive.
-Connect to Pin 2 (0 V) to enable serial communications.
-Default configuration is RS-232 with Pin 6 unconnected.
Connect to Pin 2 (0 V) to enable RS-485 serial
communications.
-Logic HIGH when a fail / fault condition exists and the SERIAL
ENABLE control input is inactive.
this table.
-0-10 V Analogue Input: 0 V = 0% Speed; +10 V = 100% Speed
Positive +10 V analogue voltage reference output: 5 mA;
1Power indicatorIndicates that electrical mains supply to the pump is ON
2Run indicatorIndicates that the pump is running. Refer to Section 4.2.1.
3Standby mode indicator
Standby speed increase
4
indicator
Standby speed decrease
5
indicator
6Auto-run indicator
7Service indicator
8Alarm indicatorIndicates an Alarm has been trigger e d. Refer to Section 5.11.6.
Indicates that the Standby mode has been selected. Refer to
Section 4.2.2.
The indicator will blink with every short push of the Standby speed
increase button. The indicator will remain ON when maximum standby
speed has been reached. Refer to Section 4.2.2.
The indicator will blink with every short push of the Standby speed
decrease button. The indicator will remain ON when minimum standby
speed has been reached. Refer to Section 4.2.2.
Indicates that the Auto-run mode has been selected. Refer to
Section 4.3.
Indicates that a service interval has been reached. Refer to
Edwards and the Edwards logo are trademarks of Edwards Limited.
A735-01-880 Issue C
WARNING
3Installation
3.1Safety
Obey the safety instructions in this section and take note of appropriate precautions. If not, injury
to people and damage to equipment can result.
Prevent any part of the human body coming into contact with the vacuum.
The Edwards nXDS pump is not recommended for pumping explosive gases or hazardous
substances.
Ensure that the pump is suitable for the application. If in doubt, refer to the Edwards guidelines on vacuum pump
and vacuum system safety (see associated publications at the end of the contents list at the front of this manual).
A suitably trained and supervised technician must pe rform the installation of the pump. Obey the safety instructions
listed below, especially when connecting the pump into an existi ng system. Details of the specific safety precautions
are given at the appropriate point in the instructions.
Installation
Wear the appropriate safety clothing if contact with contaminated components is anticipated. Dismantle and
clean contaminated components inside a fume cupboard.
Vent and purge the vacuum system before starting installation work.
Ensure that the installation technician is familiar with the safety procedures that relate to the products
handled by the pumping system.
Disconnect the other components in the pumping system from the electrical supply to prevent accidental
operation.
3.2System design considerations
Consider the following points when designing the pumping system:
Use a suitable valve to isolate the pump from the vacuum system if the pump needs to warm up before pumping
condensable vapours or if vacuum needs to be maintained when the pump is switched off.
Avoid high levels of heat input into the pump from the process gases, otherwise the pump may overheat and cause
the thermal protection system to operate.
Ensure that the exhaust pipeline cannot become blocked. If an exhaust isolation valve is installed, ensure that the
pump cannot be operated with the valve closed. Refer to Section 3.5.
Provide for a purge of inert gas when the pumping system is shut down, to dilute dangerou s gases to safe
Edwards and the Edwards logo are trademarks of Edwards Limited.
A735-01-880 Issue C
WARNING
WARNING
WARNING
3.3Unpack and inspect
Use suitable lifting equipment to move the nXDS pump. The maximum pump mass is 27 kg.
Mechanical lifting equipment should be attached to the lifting eye; loose slings should not
be used.
Take care when moving the pump into position. Its mass may make it difficult to slide. The
fan cowl is shaped to provide a handhold for positioning; the pump must not be lifted using
this handhold.
Remove all packing materials, remove the pump from its packing box, remove the protective covers from the inlet
and outlet ports and inspect the pump. If the pump is damaged, notify the supplier and carrier in writing; state the
item number of the pump together with the order number and supplier's invoice number. Retain all the packing
materials for inspection. Do not use the pump if it is damaged. If the pump is not to be used immediately, replace
the protective covers. Store the pump in suitable conditions, as described in Section 6.1. Refer to Section 6.2 for
disposal of materials.
3.4Position the pump
Installation
If the pump is to be used on the floor of a work area, position the power lead and the exhaust and
inlet hoses with care. Ensure that personnel in the area are aware of any obstructions around the
pump.
Provide a firm, level platform for the pump. Locate the pump so that the gas ballast control and the user controls
are accessible.
If the pump will be located inside an enclosure, ensure that there is adequate ventilation at both ends of the pump,
so that the ambient temperature around the pump does not exceed 40 °C. There must be a minimum space of 25 mm
between the pump and the enclosure walls.
3.4.1Mechanical fixing
Note:The pump can be secured by using the four holes located on each corner of the pump base. Edwards
recommends using M8 bolts.
3.5Connect to the vacuum system
If pumping dangerous gases or vapours, connect the exhaust to a suitable treatment plant to
prevent the discharge of dangerous gases and vapours to the surrounding atmosphere.
If the pump is operated with the exhaust line blocked, high pressure may be generated in the
exhaust line pipework.
Refer to Figure 1. Before connecting the pump to the vacuum system, remove the plastic cap from the inlet and
exhaust, and ensure that the in let strainer is fitt ed to the pump inlet port. Use appropriate NW25 vacuum fittings for
connection to the system.
Take note of the following information when connecting the pump to the vacuum system:
To minimise noise and exhaust emissions, it is recommended that the pump is connected to an exhaust line
or a silencer (refer to Section 7).
For optimum pumping speeds, ensure that the pipeline connected to the pump inlet is as short as possible
and has a suitable internal diameter.
Support the vacuum pipeline to prevent loading of the coupling joints.
A pressure of 3 barg may be generated in the exhaust pipework if th e pump is op erated with the exha ust line
blocked. Connect the pump using appropriate pipework and fittings.
If necessary, incorporate flexible bellows in the system pipelines to reduce the transmission of vibration and
to prevent loading of the coupling joints. If using flexible bellows, ensure that bellows have a maximum
pressure rating which is greater than the highest pressure that can be generated in the system. Edwards
bellows are recommended.
Incorporate an inlet isolation valve in the pipeline from the vacuum system to the pump to isolate the
vacuum system from the pump when it is switched off and prevent suck-back of process gases and debris into
the vacuum system.
Ensure that the sealing surfaces are clean and scratch-free.
Edwards recommends using an exhaust extraction system suita ble for use with all process gases that will be pumped .
Ensure that the exhaust extraction system cannot become blocked or obstructed when the pump is operating.
A small amount of tip seal wear product may collect in the exhaust duct of the pump. The dust may be blown out
with the initial burst of air after the pump has been vented. This is quite common and the amount of dust seen will
reduce over time.
Leak test the system and seal any leaks found after pump installation.
3.6Electrical installation
3.6.1Fuses and circuit breakers
Ensure that the electrical installation of the pump conforms to local and national safety
requirements. The pump must be connected to a suitably fused and protected electrical supply
with a suitable earth point.
Ensure that access to the pump electrical supply cable is not obstructed when locating the pump.
If an overload circuit breaker is used, ensure that is a time lag type.
If using an earth leakage device, for example, a Residual Current Device (RCD), use a 30 mA (minimum) rated
unit to avoid trip during start up.
The live conductor is fused inside the pump controller whilst the neutral conductor is not. An external RCD
should be installed to guard against damage in the event of a short circuit between neutral and earth.
For recommended fuse ratings, refer to Table 9 in Section 2.4.
Edwards and the Edwards logo are trademarks of Edwards Limited.
A735-01-880 Issue C
3.6.2Electrical supply connection
Use an IEC60320 connector (C13) and cable that meets local electrical stand ards when connecting to the pump. The
pump must be earthed via the earth conductor of the IEC60320 connector.
Edwards recommends fitting a separate earth to the pump using a non-insulated braid or a separate insulated green/
yellow conductor. The conductor must be a minimum of 14 AWG. Use the M5 x 10 screw and shake proof washer
located on the rear of the pump housing (refer to Figure 1) to secure the earth conductor to the pump.
3.6.3Disconnect the pump from the electrical supply
Before removing the physical electrical supply connection to the pump, via the IEC60320 cable (C13), isolate the
Mains supply (refer to Figure 1).
3.7Connection for remote control and monitoring
To operate the pump using parallel or serial control, use the 15-way D-type connector on the user interface panel
(refer to Figure 1, item 7). Refer to Table 11 for full details of the logic interface pins.
3.7.1Connect the logic interface to the control equipment
Installation
The pump can be controlled using a hardware parallel control interface and/or vi a commands sent over a serial
interface.
To control the pump using the hardware parallel interface, refer to Section 4.3 for more information. To use the
serial interface or to wor k with a mixture of parallel and serial control, refer to manual A735-01-860.
Edwards and the Edwards logo are trademarks of Edwards Limited.
A735-01-880 Issue C
CAUTION
WARNING
4Operation
Ensure that the system design does not allow the exhaust pipeline to become blocked.
A fine dust may be emitted from the exhaust of the scroll pump during start up, particularly when the pump is
new or if new tip seals are fitted.
4.1Operational modes
The nXDS pump implements three control modes:
Manual Control Mode - using buttons on user interface panel
Parallel Control Mode - via 15-way D-type logic interface connector on user interface panel
Operation
Serial Control Mode (including Serial Interlock) - via 15-way D-type logic interface connector on user
interface panel
The Control Mode is determined by the way the pump is started. Once started, the pump can only be stoppe d by the
mode in which it was started, unless the power is cycled by isolation from the electrical supply.
4.2Manual operation
The pump control functions of the user interface panel are detailed in Figure 9.
Use the buttons (Figure 9, items 3 and 12) to start and stop the pump. Note that the stop command does not isolate
the pump from the electrical supply.
4.2.2Standby
Operation at reduced speed will further improve tip seal and bearing service life. Vacuum performance will be
reduced when operating at standby speed.
Press the Standby button to select standby mode. The pump will initially run at factory default standby speed (70%
of full speed). The speed can be adjusted using the increase and decrease standby speed buttons. The maximum
standby speed is 100% of the default run speed and the minimu m standby speed is 67% of the default run speed. A
single short push will change the speed by 1% of the default run speed, holding the button will change the spee d by
1%/sec. Once adjusted, the pump will return to this new user-defined speed each time standby speed is selected.
The Standby button must be pressed to return to normal run speed.
Edwards and the Edwards logo are trademarks of Edwards Limited.
4.3Parallel control and monitoring
CAUTION
1. Start switch
2. Standby switch (optional)
3. nXDS pump logic interface
Figure 10 - Logic interface connections - parallel control
A735-01-880 Issue C
Operation
If using the normal and fail lines to drive the coils of d.c. relays, include a back EMF suppression diode in parallel
with each relay coil to protect the pump.
Connect the control equipment to the control input pins of the logic interface mating half. Refer to Table 11 to
identify the logic interface connector pins. The control inputs are as follows:
Start
Standby speed
Analogue speed
To activate any of these control inputs, connect the relevant control input (pin 14) to the 0 V control reference.
To monitor the normal status output, connect the control equipment to the Normal status output (pin 15) and to pin
2 of the logic interface mating half. The output can be used to control other devices in the pumping system. The
output can drive a low power relay of up to 24 V coil rating (up to 10 mA).
To monitor the fail status output, connect the control equipment to the fail output (pin 7) and to pin 2 of the logic
interface mating half. The output can be used to control other devices in the pumping system . The output can drive
a low power relay of up to 24 V coil rating (up to 10 mA).
The Analogue Speed input is a process control source which enables the nXDS Scroll pump to run at variable operating
speeds. This speed control source is an alternative to standby speed control.
Figure 11 - Logic interface connections - analogue speed control
Edwards and the Edwards logo are trademarks of Edwards Limited.
Figure 12 - Analogue speed control
A735-01-880 Issue C
Operation
Note:Voltages below 6.7 V will result in a clamped speed of 67% of full speed.
4.4.1Hardware configuration
Using the 15-way D-type connector (Figure 1, item 7) apply the following signal configurations to enable the Analogue
Speed Control source (refer to Table 11):
Connect the Analogue Speed Enable control input (pin 1) to the 0 V Control Reference (pin 2).
Connect a suitably calibrated analogue voltage source (0 to +10 V), for example, (DAC) to the analogue speed control
input (pin 9). Alternatively connect the output of a potentiometer referenced to the pump reference voltage (pin 11)
to the analogue speed control input (pin 9). Refer to Figure 11. The 0 V rail of the external voltage source must be
connected to the 0 V Control Reference (pin 2) of the pump controller.
4.4.2Operation
A +10 V input equates to a mechanical running speed which is equal to: 100% of the default run speed, that
is, 30 Hz.
The minimum running speed provided by the Analogue Speed control source, is clamped at the minimum
Standby Speed Setting, that is, approximately 67% of the default run speed of 20 Hz.
The maximum running speed provided by the Analogue Speed control source is clamped by the maximum
Standby Speed Setting, that is, 100% of the default run speed of 30 Hz.
The auto-run setting configures the pump to start at power-up without any custom er interventi on. This paramete r is
customer configurable via serial communications, or using the START / STOP buttons. Holding down either the START
or STOP button, for more than eight seconds, will enable or disable the auto-run setting. The status of the auto-run
setting is visible via the auto-ru n LED.
The pump can be stopped using either manual, parallel or serial control modes whilst in auto-run.
4.6Use of gas ballast control
The gas ballast control can be used to optimise the performance of the scroll pump for the application. The
performance characteristics of the pump with gas ballast on are shown in Section 2.2.3. The position of the gas
ballast control can be changed when the pump is either off or operating.
4.6.1Gas ballast control
Use the gas ballast control to introduce air into the final stage of the pump. Use of gas ballast will reduce the
condensation of vapours in the pump; the condensates would contaminate the pump.
There are only two positions, 0 and 1. The gas ballast control knob will rotate 360° in either direction at 90° intervals.
Gas ballast OFF (position 0). Use this setting to:
achieve ultimate vacuum
pump dry gases.
Gas ballast ON (position 1). Use this setting to:
pump low concentrations of condensable vapours
decontaminate the pump.
4.7Start up procedure
Use the procedure below to start up the pump:
1. Ensure that any vacuum system isolation valve is closed (if fitted).
2. With the mains supply to the pump isolated, connect a recommended lead to the electrical socket on the pump
(refer to Figure 1).
3. Apply power.
4. Start the pump system using the appropriate control source, that is, using the Start button in manual control
mode (refer to Figure 9); the Start/Stop control input (refer to Table 11, pin 3) in parallel control mode or a
Start command in serial control mode.
5. Open the vacuum system isolation valve, if fitted.
Edwards and the Edwards logo are trademarks of Edwards Limited.
A735-01-880 Issue C
4.8To achieve ultimate vacuum
In order to achieve the best possible vacuum, the pump should be operated with the gas ballast control turned off.
However, if the pump, or elements of the vacuum system it is attached to, are new or have been newly fitted, some
atmospheric moisture may be present. If atmospheric moisture is present, run the pump with gas ballast on for
20 minutes before turning gas ballast off. If moisture is allowed to remain, the performance of the pump will be
impaired.
4.9To pump condensable vapours
Select gas ballast ON when there is a high proportion of condensable vapours in the process gases. This will assist the
vapours to pass through the pump without condensing and keep the pump performance from degrading.
4.10Shut down
Use the procedure below to shut down the pump:
1. If shutting the pump down prior to a period of storage, remove any process gases by ru nnin g on a ga s b allast fo r
at least one hour.
2. Close any vacuum system isolation valves to prevent suck-back into the vacuum system (where fitted).
Operation
3. Stop the pump system using the appropriate control source, that is, using the Stop button in manual control
mode (refer to Figure 9); the Start/Stop control input (refer to Table 11, pin 3) in parallel control mode or a Stop
command in serial control mode.
4. Vent th e nXDS pump system using the gas ballast control or the valve on the inlet.
Edwards and the Edwards logo are trademarks of Edwards Limited.
5Maintenance
CAUTION
WARNING
WARNING
WARNING
WARNING
WARNING
5.1Safety information
Obey the safety instructions in this section and take note of appropriate precautions. Failure to
observe these instructions may result in injury to people and damage to equipment.
In order to maintain the ATEX certification, all maintenance work has to be carried
out in accordance with this nXDS instruction manual, the nXDS Replacement Tip Seal
manual and the nXDS maintenance manual, using only genuine Edwards spare parts.
Disconnect the pump and other components from the electrical supply to prevent accidental
operation.
A735-01-880 Issue C
Maintenance
The pump may be contaminated with the process chemicals that have been pumped during
operation. If so, ensure that the pump is decontaminated before maintenance and adequate
precautions taken to protect people from the effects of dangerous substances if contamination has
occurred.
Do not touch or inhale the thermal breakdown products of fluorinated materials which may be
present in the pump if the pump has been heated to 260 °C and above. Fluorinated materials are
safe in normal use but can decompose into very dangerous substances (which may include
hydrofluoric acid) if heated to 260 °C and above. The pump may have overheated if it was misused
or if it was in a fire. Safety Data Sheets for fluorinated materials used in the pump are available on
request; contact the supplier or Edwards.
External surfaces of the pump should be cleaned using warm soapy water. Care must be taken with solventbased cleaning fluids as they may remove important information from the product labels.
The pump is designed to require little user maintenance. Observe the following guidelines when carrying out
maintenance on the pump:
Ensure the maintenance is done by a suitably trained and supervised technician. Obey local and national
safety requirements.
Ensure the maintenance technician is familiar with the safety procedures which relate to the products
processed by the pumping system.
Check that all the required parts are available and are of the correct type before starting work.
Isolate the pump and other components from the electrical supply to prevent accidental operation.
Allow the pump to cool for at least 3 hours before starting maintenance work.
More frequent maintenance may be required if the pump is used to pump aggressive gases or vapours, such as
solvents, organic substances and acids, or if the pump is operated continuously at the higher end of its operating
temperature.
Table 13 - Maintenance plan
Operation
Inspect and clean the inlet strainer12No5.3
Inspect and clean the external fan cover if required12No5.4
Check the pump performance30Yes5.5
Replace the pump bearings60Yes5.6
Replace the pump controller120Yes5.6
Electrical safety check60No5.8
For service indicator codes, refer to Section 5.10.
Frequency
(months)
Service
indicator
Section
reference
5.3Inspect and clean the inlet strainer
Whenever the pump is disconnected from the vacuum system, or on an annual basis, Edwards recommends:
Removing the inlet strainer from the pump inlet (refer to Figure 1) and remove any debris that may have
accumulated.
Inspecting the inlet strainer and if necessary , clean it with a cleaning solution suitable for the substances
pumped. Refit the inlet strainer before reconnecting the pump to the vacuum system. Refer to Section 3.5.
5.4Clean the external fan cover
If the fan cover is not kept clean, the air flow over the pump can be restricted and the pump may overheat.
1. Switch off the pump and disconnect it from the electrical supply.
2. Use a dry cloth and a soft brush to remove dirt and deposits from the fan cover.
5.5Check the pump performance (service indicator)
The service indicator, (flashing ON 1s / OFF 1s) is triggered as a reminder to check the performance of the pump.
The service indicator will flash to indicate that a tip-seal change may b e re quire d (bas ed on ty pical ti p-s eal life). If
after checking, the pump is no longer achieving the required performance, Edwards recommends carrying out a tipseal replacement (refer to Section 5.10).
If however the pump performance is still within acceptable limits, or is performing satisfactorily, the tip-seal
replacement can be delayed.
If operating a preventative maintenance plan, depending upon the particular regime, a tip-seal change can be ca rried
out at this time irrespective of the pump performance.
To reset the service indicator, refer to Section 5.10.
Edwards and the Edwards logo are trademarks of Edwards Limited.
A735-01-880 Issue C
5.6Replace the tip-seals
This information is applicable to the nXDS replacement tip seal kit that must be fitted. Refer to Section 7.3.1 for
ordering information.
A tip-seal replacement should be carried out to maintain or restore the pumps performance. The frequency for
replacing the pump tip-seals is determine by the following factors:
The pump has reached a service interval. R efer to Sections 5.5 and 5.7.
The pump is no longer achieving the required performance.
If the pump is no longer achieving the required performance prior to a service interval being reached, Edwards
recommends first following the guide lines, refer to Section 5.11.2.
Note:There may be a running-in period after fitting your new tip-seals. The performance should improve over a
period of 24 to 48 hours. If the pump performance does not improve sufficiently after the running-in period,
please contact Edwards for advice.
For information on how to replace the nXDS tip-seals and Health and Safety, refer to the nXDS replacement tip seal
kit instruction manual A735-02-840 which is included on the CD manual. Also refer to Youtube video at
https://www.youtube.com/watch?v=vKnh9dxOyhE.
Maintenance
5.7Replace the pump bearings (service indicator)
The service indicator, (flashing ON 3s / OFF 1s) is triggered to indicate that a bearing replacement service interval
has been reached. Bearing wear cannot necessarily be detected unde r normal operating conditions. This service
interval is a recommendation that a bearing replacement is required, this is especially useful if operating a
preventative maintenance plan.
It is possible for an experienced technician, who is suitably trained, to perform mainte nance and repair on nXDS
pumps up to and including bearing replacement. Edwards has developed a detailed maintenance manual and
instructional video (Edwards part number A73501713) that will enable an experienced technician to undertake this
work. If required Edwards can also provide face to face training. Please contact Edwards for more information or to
purchase this training.
Note:Failure to replace the pump bearings at this time may subsequently lead to damage of the pumping
mechanism.
Note:A tip-seal change and exhaust and ballast valve change should be carried out at the same time when
performing a bearing replacement. Refer to Section 7.3 for ordering information.
To reset the service indicator, refer to Section 5.10.
5.8Replace the pump controller (service indicator)
The service indicator, (flashing ON 3s / OFF 3s) is triggered to indicate that the pump controller should be replaced.
Contact Edwards for further details.
To reset the service indicator, refer to Section 5.10.
5.9Electrical safety check
Test the earth continuity and the insulation resistance of the pump system in accordance with local regulations for
the periodic testing of electrical equipment.
The earth continuity should be less than 0.1Ω and the DC insulation resistance greater than 1.0 MΩ.
If the pump fails any of these tests, the supplier or Edwards must be contacted.
The nXDS controller incorporates a service indicator (refer to Figure 7). The service indicator will flash a specific
code whenever a service interval has been reached. There are three service levels listed in Table 14.
Table 14 - Flashing service codes
Service flash codeCommentsSee section
ON 1s / OFF 1sPump performance check.5.5
ON 3s / OFF 1sPump bearing service.5.6
ON 3s / OFF 3sPump-Controller service.5.7
To reset the service indicator, press and hold the standby speed increase and decrease buttons simultaneously for
more than 5 seconds.
Note:Resetting the pump bearing service indicator will also reset the performance check timer, that is, both
counters will be set to zero.
Note:Resetting the service indicator will reset the service timer back to zero (refer to Table 13).
5.11Fault finding
5.11.1The pump has failed to start or has stopped
The electrical supply fuse has blown.
The ambient temperature is too high.
The cooling air supply is insufficient or is too hot.
The process gas is too hot or the throughput is too high.
The fan is not working or is not connected.
The motor is faulty.
5.11.2The pump has failed to achieve the required performance
Gas ballast may be selected. To close gas ballast, turn the control a quarter turn so that the valve snaps
shut. Use this setting to achieve the best possible vacuum. If the pump has been used to pump condensable
vapours or is to pump a large chamber that has been exposed to atmospheric air (water vapour), it may be
necessary to run for at least an hour on gas ballast.
If the electrical supply voltage is more than 10% below the lowest voltage specified on the user interface
panel, the pump may operate but deliver a degraded vacuum performance.
There is a leak in the system.
Tip seals may need further run-in, typically 24 hours, with some requiring up to a maximum of 100 hours.
The pressure measurement technique or gauge head is unsuitable or gives an incorrect indication of
pressure.
The vacuum fittings are dirty or damaged; replace the fittings.
The inlet strainer is blocked; clean or replace the strainer.
The connecting pipelines are too long or too small in diameter; conductance.
There is high pressure or a blockage in the exhaust line.
The pump contains traces of process vapours; run 12 hours with gas ballast.
Edwards and the Edwards logo are trademarks of Edwards Limited.
The pump is outside the specified range of operating conditions.
The tip seals need replacing.
The pump is in standby mode.
5.11.3The pump has poor ultimate vacuum
If the pump exhibits poor ultimate vacuum, refer to Figure 13.
Figure 13 - Poor ultimate vacuum flow chart
A735-01-880 Issue C
Maintenance
5.11.4The pump is noisy
If the pump is noisy, refer to Figure 14.
5.11.5The pump surface temperature is high
The ambient temperature is too high.
The cooling fan is not running.
The process gas is too hot or the maximum continuous operating pressure has been exceeded.
Whenever a fail condition becomes active the red alarm indicator shows a flashing sequ ence. If the error light is on
continuously this indicates a problem has been found with the embedded software. In this case, try cycling the
power. If cycling the power does not clear the indication, a software download may be required. In this situation,
contact the supplier or Edwards. If the alarm indicator is flash ing, identify the error flash cod e and consult Table 15.
There is a sufficient off period between each subsequent cycle repetition to clearly mark the start of a new flash
sequence. The duration of a long flash (L) is equal to 3 times the duration of a short flash (0.5 s).
Edwards and the Edwards logo are trademarks of Edwards Limited.
A735-01-880 Issue C
7Spares and accessories
7.1Introduction
Edwards products, spares and accessories are available from Edwards companies in Belgium, Brazil, China, France,
Germany, Israel, Italy, Japan, Korea, Singapore, United Kingdom, U.S.A and a world-wide network of distributors.
The majority of these centres employ Service Engineers who have undergone comprehensive Edwards training
courses.
Order spare parts and accessories from the nearest Edwards company or distributor. When ordering, state for each
part required:
Model and item number of your equipment
Serial number
Item number and description of part
Edwards and the Edwards logo are trademarks of Edwards Limited.
A735-01-880 Issue C
7.2.1Silencer
A silencer is available for the nXDS pump. Refer to Section 3.5 for guidance on its use.
Table 16 - Silencer
Product descriptionOrdering information
Silencer NW25A505-97-000
7.2.2Gas ballast adaptor
A gas ballast adaptor may be fitted in place of the gas ballast control on the pump. The adaptor allows a controlled
supply of inert gas to be connected to the pump.
Table 17 - Gas ballast adaptor
Product descriptionOrdering information
Gas ballast adaptor with fine restrictorA735-01-809
Gas ballast adaptor without fine restrictorA735-01-811
7.2.3Gas ballast adaptor blank
Spares and accessories
This adaptor kit allows the conversion of a standard nXDS pump into an nXDS-R version. The gas ballast control is
replaced with a blank adaptor so that the gas ballast cannot be accidentally opened. This feature is useful for
applications such as rare gas recirculation or gas recovery. Another advantage is improved leak tightness at this
location.
Table 18 - Gas ballast blank adaptor
Product descriptionOrdering information
Gas ballast blank adaptorA735-01-806
7.2.4Vibration isolators
Fit vibration isolators to the pump to reduce the transmitted vibration from the pump to a structure, such as a frame
or a system.
Table 19 - Vibration isolators
Product descriptionOrdering information
Vibration isolators (pack of 4)A248-01-441
7.2.5Inlet/exhaust filter
The inlet dust filter has two functions. It can be connected inline betw een the p ump i nlet and y our cha mber outlet
connection to prevent dust from migrating into your system. Alternatively, it can be connected inline between the
pump exhaust and your exhaust extraction system. The filter is supplied ready to use with a 5 μm element.
Note:If connecting the exhaust filter onto the pump outlet, an NW25 / hose nozzle, C105-14-328 is availab le to
The exhaust nozzle screws into the outlet flange. Use the exhaust nozzle to connect the pump to the 12 mm internal
diameter plastic hose.
Table 21 - Exhaust nozzle
Product descriptionOrdering information
Exhaust nozzleA505-09-000
7.2.7Chemical resistance conversion kit
This adaptor kit allows a standard nXDS pump to be converted into an nXDS-C version. This conversion may be
necessary if the pump is used on applications involvin g corrosive substances. For more information, contact Edwards.
Note: If returning the pump to Edwards for repair or service having been converted from a standard version to
an nXDS-C version, Edwards service must be informed, otherwise the pump will be returned back as a
standard version.
Table 22 - Chemical resistance conversion kit
Product descriptionOrdering information
Chemical adaptor kit for nXDS 6i, 10i or 15iA735-01-807
Chemical adaptor kit for nXDS20iA735-01-808
7.2.8Electrical cables
Refer to Table 23. The following electrical cables are available as accessories and should be used to connect the nXDS
pump to the electrical supply.
s
Product descriptionOrdering information
Lead Assembly, 10 A, C13, UKA505-05-000
Lead Assembly, 10 A, C13, EuropeA505-06-000
Lead Assembly, 10 A, C13, USAA505-07-000
Lead Assembly, 10 A, C13, No PlugA505-08-000
Table 23 - Electrical cables
7.2.9Pump-to-controller cable
Use the control cable to control the nXDS pump using an Edwards Turbo Instrument Controller (TIC) or TIC Turbo
Controller, or a (TAG) Active Gauge controller.
Table 24 - Pump-to-controller cables
Product descriptionOrdering information
1 m cableD395-00-835
2 m cableD395-00-836
5 m cableD395-00-837
7.3.6Bearing replacement kit (not field serviceable)
Used when the pump has reached a long run service interval. Specific training is required to replace the bearings on
nXDS pumps. See Section 5.7 for details of Edwards options for providing this training.
Table 30 - Bearing replacement kit
Product descriptionOrdering information
Bearing replacement kitA735-01-802
7.3.7Exhaust and ballast valve kit
Used when the pump has reached a long run service interval.
Table 31 - Exhaust and ballast valve kit
Product descriptionOrdering information
Exhaust and ballast valve kit (standard and R versions)A735-01-803
Exhaust and ballast valve kit (C versions only)A735-01-804
Note:nXDS20i, nXDS20iR and nXDS20iC versions require two service kits per pump.