Watson-Marlow 323S User manual

Watson-Marlow 323E, 323S, 323U and 323Du User Manual 1
WATSON-MARLOW BREDEL MANUALS
Watson-Marlow 323E, 323S,
323U and 323Du pumps
m-323e-s-u-du-gb-06
Contents
1 Declaration of conformity 2
2 Declaration of incorporation 2
3 Two-year warranty 3
4 When you unpack your pump 4
5 Information for returning pumps 5
6 Peristaltic pumps: an overview 6
7 Safety notes 7
8 Pump specifications 9
8.1 Pump features 9
8.2 Dimensions 14
9 Good pump installation practice 15
9.1 General recommendations 15
9.2 Do’s and do not’s 16
10 Connecting this product to a
power supply 17
11 Start-up check list 18
12 Switching the pump on 18
13 Auto-restart facility 19
14 Manual operation 20
15 Keypad lock 21
16 MemoDose 22
17 Automatic operation with
analogue signals, remote
control or RS232 link 23
17.1 Analogue signals and
remote control 24
17.2 Automatic control wiring
using the 720N module 26
18 Care and maintenance 28
19 Troubleshooting 28
19.1 Error messages 29
20 Drive maintenance 30
21 Drive part numbers 30
22 Drive spares 31
23 Pumpheads 32
23.1 Pumpheads: key safety
information 32
23.2 313D and 314D
pumpheads 32
23.3 313D and 314D
pumphead order codes 34
23.4 313D and 314D flow rates 35
23.5 313D and 314D:
maximum number of
pumpheads 36
23.6 313D and 314D:
tubing part numbers 37
23.7 314MC and 318MC
microcassette pumpheads 38
23.8 314MC and 318MC
microcassette pumphead
spares 40
23.9 314MC and 318MC
flow rates 41
23.10 314MC and 318MC
tubing part numbers 42
23.11 501RL pumphead 43
23.12 501RL and 501RL2
installation 43
23.13 501RL and 501RL2
tube loading 43
23.14 501RL and 501RL2
rotor settings 44
23.15 501RL and 501RL2
pumphead spares 45
23.16 501RL and 501RL2
flow rates 46
23.17 501RL and 501RL2
tubing part numbers 46
24 Trademarks 47
25 Warning not to use pumps in
patient-connected applications 47
26 Publication history 47
27 Decontamination certificate 48

Watson-Marlow 323E, 323S, 323U and 323Du User Manual 2
1 Declaration of conformity
This declaration was issued for Watson-Marlow 323E, 323S, 323U and
323Du pumps on November 1, 2007. When this pump unit is used as a
stand-alone pump it complies with: Machinery Directive 2006/42/EC, EMC
Directive 2004/108/EC.
This pump is ETL listed: ETL control number 3050250. Cert to CAN/CSAstd
C22.2 No 61010-1. Conforms to UL std 61010A-1.
See 8 Pump specifications.
2 Declaration of incorporation
When this pump unit is to be installed into a machine or is to be assembled with other
machines for installations, it must not be put into service until the relevant machin-
ery has been declared in conformity with the Machinery Directive 2006/42/EC.
Responsible person: Christopher Gadsden, Managing Director, Watson-Marlow Lim-
ited, Falmouth, Cornwall TR11 4RU, England. Telephone [phone] Fax
[phone].
The information in this user guide is believed to be correct at the time of publication.
However, Watson-Marlow Limited accepts no liability for errors or omissions. Watson-
Marlow Bredel has a policy of continuous product improvement, and reserves the
right to alter specifications without notice. This manual is intended for use only with
the pump it was issued with. Earlier or later models may differ. The most up-to-date
manuals appear on the Watson-Marlow website: http://www.watson-marlow.com
E, S, U, Du
E, S, U, Du

Watson-Marlow 323E, 323S, 323U and 323Du User Manual 3
E, S, U, Du 3 Two-year warranty
Watson-Marlow Limited ("Watson-Marlow") warrants, subject to the conditions and
exceptions below, through either Watson-Marlow, its subsidiaries, or its authorised
distributors, to repair or replace free of charge, any part of the product which fails
within two years of the day of manufacture of the product. Such failure must have oc-
curred because of defect in material or workmanship and not as a result of operation
of the product other than in normal operation as defined in this pump manual.
Watson-Marlow shall not be liable for any loss, damage, or expense directly or indi-
rectly related to or arising out of the use of its products, including damage or injury
caused to other products, machinery, buildings, or property, and Watson-Marlow shall
not be liable for consequential damages, including, without limitation, lost profits,
loss of time, inconvenience, loss of product being pumped, and loss of production.
This warranty does not obligate Watson-Marlow to bear any costs of removal, instal-
lation, transportation, or other charges which may arise in connection with a war-
ranty claim.
Conditions of and specific exceptions to the above warranty are:
Conditions
Products must be returned by pre-arrangement, carriage-paid, to Watson-Mar-
low, or a Watson-Marlow approved service centre.
All repairs or modifications must have been made by Watson-Marlow Limited, or
a Watson-Marlow approved service centre or with the express permission of
Watson-Marlow.
Warranties purporting to be on behalf of Watson-Marlow made by any person,
including representatives of Watson-Marlow, its subsidiaries, or its distributors,
which do not accord with the terms of this warranty shall not be binding upon
Watson-Marlow unless expressly approved in writing by a Director or Manager of
Watson-Marlow.
Exceptions
The warranty shall not apply to repairs or service necessitated by normal wear
and tear or for lack of reasonable and proper maintenance.
All tubing and pumping elements as consumable items are excluded.
Products which, in the judgment of Watson-Marlow, have been abused, misused,
or subjected to malicious or accidental damage or neglect are excluded.
Electrical surge as a cause of failure is excluded.
Chemical attack is excluded
All pumphead rollers are excluded.
Pumpheads from the 313/314 retain their one-year standard pumphead war-
ranty. The drive they are attached to is subject to the two-year warranty as set
out here.
Ancillaries such as leak detectors are excluded.

Watson-Marlow 323E, 323S, 323U and 323Du User Manual 4
E, S, U, Du 4 When you unpack your pump
Unpack all parts carefully, retaining the packaging until you are sure all components
are present and in good order. Check against the components supplied list, below.
Packaging disposal
Dispose of packaging materials safely, and in accordance with regulations in your
area. The outer carton is made of corrugated cardboard and can be recycled.
Inspection
Check that all components are present. Inspect components for damage in transit. If
anything is missing or damaged, contact your distributor immediately.
Components supplied
Watson-Marlow 323E, 323S, 323U and 323Du pumps are supplied as:
Dedicated 323E, 323S, 323U or 323Du pump drive unit fitted with one or more
313 or 314 pumpheads (see 8 Pump specifications).
The designated mains power lead for your pump
PC-readable CDROM containing these operating instructions
Quick Start manual
Note: Some versions of this product will include components different from those
listed above. Check against your purchase order.
Storage
This product has an extended shelf life. However, care should be taken after storage
to ensure that all parts function correctly. Users should be aware that the pump con-
tains a battery with an unused life of seven years. Long-term storage is not recom-
mended for peristaltic pump tubing. Please observe the storage recommendations
and use-by dates which apply to tubing you may wish to bring into service after stor-
age.

Watson-Marlow 323E, 323S, 323U and 323Du User Manual 5
E, S, U, Du 5 Information for returning pumps
Equipment which has been contaminated with, or exposed to, body fluids, toxic chem-
icals or any other substance hazardous to health must be decontaminated before it
is returned to Watson-Marlow or its distributor.
A certificate included at the rear of these operating instructions, or signed statement,
must be attached to the outside of the shipping carton. This certificate is required
even if the pump is unused. See 27 Decontamination certificate.
If the pump has been used, the fluids that have been in contact with the pump and
the cleaning procedure must be specified along with a statement that the equipment
has been decontaminated.

Watson-Marlow 323E, 323S, 323U and 323Du User Manual 6
E, S, U, Du 6 Peristaltic pumps - an overview
Peristaltic pumps are the simplest pump, with no valves, seals or glands to clog or
corrode. The fluid contacts only the bore of a tube, eliminating the risk of the pump
contaminating the fluid, or the fluid contaminating the pump. Peristaltic pumps can
run dry.
How they work
A compressible tube is squeezed between a roller and a track on an arc of a circle,
creating a seal at the point of contact. As the roller advances along the tube, the seal
also advances. After the roller has passed, the tube returns to its original shape, cre-
ating a partial vacuum which is filled by fluid drawn from the inlet port.
Before the roller reaches the end of the track, a second roller compresses the tube
at the start of the track, isolating a packet of fluid between the compression points.
As the first roller leaves the track, the second continues to advance, expelling the
packet of fluid through the pump’s discharge port. At the same time, a new partial
vacuum is created behind the second roller into which more fluid is drawn from the
inlet port.
Backflow and siphoning do not occur, and the pump effectively seals the tube when
it is inactive. No valves are needed.
The principle may be demonstrated by squeezing a soft tube between thumb and fin-
ger and sliding it along: fluid is expelled from one end of the tube while more is drawn
in at the other.
Animal digestive tracts function in a similar way.
Suitable applications
Peristaltic pumping is ideal for most fluids, including viscous, shear-sensitive, corro-
sive and abrasive fluids, and those containing suspended solids. They are especially
useful for pumping operations where hygiene is important.
Peristaltic pumps operate on the positive displacement principle. They are particularly
suitable for metering, dosing and dispensing applications. Pumps are easy to install,
simple to operate and inexpensive to maintain.

Watson-Marlow 323E, 323S, 323U and 323Du User Manual 7
E, S, U, Du 7 Safety notes
In the interests of safety, this pump and the tubing selected should only be used by
competent, suitably trained personnel after they have read and understood this man-
ual, and considered any hazard involved. If the pump is used in a manner not spec-
ified by Watson-Marlow Limited, the protection provided by the pump may be
impaired.
This symbol, used on the pump and in this manual,
means: Caution, refer to accompanying documents.
This symbol, used on the pump and in this manual,
means: Do not allow fingers to contact moving parts.
This symbol, used on the pump and in this manual,
means: Recycle this product under the terms of the EU
Waste Electrical and Electronic Equipment (WEEE) Di-
rective.
Fundamental work with regard to lifting, trans-
portation, installation, starting-up, maintenance
and repair should be performed by qualified per-
sonnel only. The unit must be isolated from mains power while
work is being carried out.
Any person who is involved in the installation or periodic maintenance of this equip-
ment should be suitably skilled or instructed and supervised using a safe system of
work. In the UK this person should also be familiar with the Health and Safety at
Work Act 1974.
There is a user-replaceable type T1.0AH 250V fuse
in the fuse drawer of the IEC mains connector at
the back of the pump, which also contains a spare
fuse. In some countries, the mains power plug
contains an additional replaceable fuse. There are no user-ser-
viceable fuses or parts inside this pump.

Watson-Marlow 323E, 323S, 323U and 323Du User Manual 8
There are moving parts inside the pumphead. Before opening the track, en-
sure that the following safety directions are followed.
Ensure that the pump is isolated from the mains power.
Ensure that there is no pressure in the pipeline.
If a tube failure has occurred, ensure that any fluid in the pumphead has been
allowed to drain to a suitable vessel, container or drain.
Ensure that protective clothing and eye protection are worn if hazardous fluids
are pumped.
Primary operator protection from rotating parts of the pump is provided by the
pumphead track. See 23 Pumpheads.
This product does not comply with the ATEX directive
and must not be used in explosive atmospheres.
This pump must be used only for its intended purpose. The pump must be accessible
at all times to facilitate operation and maintenance. Access points must not be ob-
structed or blocked. The pump’s mains plug is the disconnecting device (for isolating
the motor drive from the mains supply in an emergency). Do not position the pump
so that it is difficult to disconnect the mains plug. Do not fit any devices to the drive
unit other than those tested and approved by Watson-Marlow. Doing so could lead to
injury to persons or damage to property for which no liability can be accepted.
If hazardous fluids are to be pumped, safety procedures specific to the particular fluid
and application must be put in place to protect against injury to persons.
The exterior surfaces of the pump may get hot during operation. Do not take hold of
the pump while it is running. Let it cool after use before handling it.
No attempt should be made to run the drive without a pumphead fitted.

Watson-Marlow 323E, 323S, 323U and 323Du User Manual 9
E, S, U, Du 8 Pump specifications
Labels fixed to the rear of the pump contain manufacturer and contact details,
product reference number, serial number and model details.
Features 323E 323S 323U 323Du
Manual control • • • •
Backlight • • • •
Beeper • • • •
Manual screen: rpm • • • •
15-400 rpm 27:1 speed control •
3-400 rpm 133:1 speed control • • •
1.5-220 rpm 147:1 speed control • • •
5 rpm scrolling increment •
1 rpm scrolling increment • • •
Auto-restart • • •
Keypad lock • • •
MemoDose • • •
Analogue input: 4-20mA, 0-10V • •
Remote stop/start control • •
Remote direction control • •
RS232 control •
313D and 314D pumpheads • • • •
501RL and 501RL2 pumpheads • • •
314MC and 318MC pumpheads • • •
~100-120V/~220-240V operation • • • •
IP31 wipe-down case • • • •
8.1 Pump features

Watson-Marlow 323E, 323S, 323U and 323Du User Manual 10
15-400 rpm 3-400 rpm
Four models of 323 drives are documented in this manual: 323E, 323S, 323U and
323Du, with varying functionality, as described earlier in this section. The 323E is fit-
ted with a short-nosed gearbox, offers 15-400 rpm, and can be fitted with a 313 or
314 pumphead. The 323S, 323U and 323Du are available with a choice of gearboxes:
a short-nosed gearbox, which offers 3-400 rpm and can be fitted with a 313 or 314
pumphead, or a 314MC or a 318MC pumphead; and a long-nosed gearbox, which of-
fers 1.5-220 rpm and can be fitted with a 501RL or a 501RL2 pumphead. See 23
Pumpheads.
323S, 323U, 323Du
1.5-220 rpm
323E

Watson-Marlow 323E, 323S, 323U and 323Du User Manual 11
IP NEMA
1st Digit 2nd Digit
3
Protected against
ingress of solid objects
with a diameter of
more than 2.5mm.
Tools, wires etc with a
thickness of more than
2.5mm are prevented
from approach
1
Protection against
dripping water falling
vertically. No harmful
effect must be
produced
2
Indoor use to provide a
degree of protection
against limited
amounts of falling
water and dirt
5
Protected against
harmful dust deposits.
Ingress of dust is not
totally prevented but
the dust must not
enter in sufficient
quantity to interfere
with satisfactory
operation of the
equipment. Complete
protection against
contact
5
Protection against
water projected from a
nozzle against the
equipment (enclosure)
from any direction.
There must be no
harmful effect (water
jet)
12
Indoor use to provide a
degree of protection
against dust, falling
dirt and dripping, non-
corrosive liquids
13
Indoor use to provide a
degree of protection
against dust and spray-
ing of water, oil and
non-corrosive coolants
6
Protection against
ingress of dust (dust-
tight). Complete
protection against
contact
6
Protection against
heavy seas or powerful
water jets. Water must
not enter the
equipment (enclosure)
in harmful quantities
(splashing over)
4X
Indoor or outdoor use*
to provide a degree of
protection against
splashing water, wind-
blown dust and rain,
hose-directed water;
undamaged by the
formation of ice on the
enclosure. (Resist
corrosion: 200-hour
salt spray)
IP (Ingress Protection) and NEMA definitions
* Protect from prolonged UV exposure.

Watson-Marlow 323E, 323S, 323U and 323Du User Manual 12
Supply voltage/frequency 100-120V/200-240V 50/60Hz 1ph
Maximum voltage fluctuation
±10% of nominal voltage. A well
regulated electrical mains supply is re-
quired along with cable connections con-
forming to the best practice of noise
immunity
Installation category
(overvoltage category) II
Power consumption 100VA
Full load current <0.43A at 230V; <0.86A at 115V
Eprom version Accessible through pump software
Enclosure rating
IP31 to BS EN 60529; Equivalent to
NEMA 2. Suitable for indoor use. Pro-
tected against dripping water and falling
dirt. May be wiped with a damp cloth but
should not be immersed
Operating temperature range 4C to 40C, 40F to 104F
Storage temperature range -40C to 70C, -40F to 158F
Maximum altitude 2,000m, 6,560ft
Humidity (non-condensing) 80% up to 31C, 88F, decreasing
linearly to 50% at 40C, 104F
Weight See 8.2 Dimensions
Noise <70dB(A) at 1m
Pump specifications

Watson-Marlow 323E, 323S, 323U and 323Du User Manual 13
EC
harmonised
standards
Safety of machinery—electrical equipment of machines:
BS EN 60204-1
Safety requirements for electrical equipment for
measurement, control and laboratory use:
BS EN 61010-1 incorporating A2 Category 2, Pollution degree 2
Degrees of protection provided by enclosures (IP code):
BS EN 60529 amendments 1 and 2
Conducted emissions:
BS EN 55011 A1 and A2, Class A, called by BS EN 61000-6-4
Radiated emissions:
BS EN 55011 A1 and A2, Class A, called by BS EN 61000-6-4
Electrostatic discharge: BS EN 61000-4-2
Radiated RF immunity:
BS EN 61000-4-3 A1 and A2, called by BS EN 61000-6-2
Fast transient burst:
BS EN 61000-4-4 A1 and A2, Level 3 (2kV),
called by BS EN 61000-6-2
Surge immunity:
BS EN 61000-4-5 A1 and A2, called by BS EN 61000-6-2
Conducted RF immunity:
BS EN 61000-4-6, called by BS EN 61000-6-2
Voltage dips and interruptions:
BS EN 61000-4-11, called by BS EN 61000-6-2
Mains harmonics: BS EN 61000-3-2 A2
Pumps and pump units for liquids—common safety
requirements: BS EN 809
Other
standards
UL 61010A-1
CAN/CSA-C22.2 No 61010-1
Conducted emissions FCC 47CFR, Part 15.107
Radiated emissions FCC 47CFR, Part 15
NEMA 2
Standards

Watson-Marlow 323E, 323S, 323U and 323Du User Manual 14
8.2 Dimensions in millimetres
323E/D, 323S/D, 323U/D, 323Du/D
323S/MC, 323U/MC, 323Du/MC
323S/RL, 323U/RL, 323Du/RL
Drive only + 313 + 501RL
323 4.2kg, 9lb 4oz 4.5kg, 9lb 14oz 5.5kg, 12lb 2oz
Unit weights

Watson-Marlow 323E, 323S, 323U and 323Du User Manual 15
E, S, U, Du 9 Good pump installation practice
9.1 General recommendations
Position
A correctly engineered installation will promote long tube life. Site the pump on a
flat, horizontal, rigid surface, free from excessive vibration. Allow a flow of air around
the pump to ensure that heat can be dissipated. Ensure that the temperature around
the pump does not exceed 40C.
Emergency disconnection
The pump’s mains plug is the disconnecting device (for isolating the motor drive from
the mains supply in an emergency). Do not position the pump so that it is
difficult to disconnect the mains plug. The STOP key on the keypad will always stop
the pump. However, it is recommended that a suitable local emergency stop device
is fitted into the mains supply to the pump.
Valves
Peristaltic pumps are self-priming and self-sealing against backflow. No valves are
required in inlet or discharge lines. Valves in the process flow must be opened before
the pump operates. Users are advised to fit a pressure relief device between the pump
and any valve on the discharge side of the pump to protect against damage caused
by accidental operation with the discharge valve closed.
The pump may be set up so that the direction of rotor rotation is clockwise or
counter-clockwise, whichever is convenient.
Tubing materials: run-in advice
Sta-Pure and Marprene tubing are hard to compress when new. When using
tubing made of these materials, the first 30 seconds should be at a speed of 10 rpm
or greater. If the pump is run slower, the safety system built into pump drive’s soft-
ware may cause it to stop and display an over-current error message.

Watson-Marlow 323E, 323S, 323U and 323Du User Manual 16
9.2 Do’s and do not’s
Do operate the pump on a flat horizontal surface. The pump requires a free flow of
air for cooling. Do not block the air vents beneath the pump or at the rear.
Do not stack pumps more than three high.
Do use only single phase mains electricity supplies.
Do keep delivery and suction tubes as short and direct as possible - though ideally
not shorter than 1m - and follow the straightest route. Use bends of large radius: at
least four times the tubing diameter. Ensure that connecting pipework and fittings
are suitably rated to handle the predicted pipeline pressure. Avoid pipe reducers and
lengths of smaller bore tubing than the pumphead section, particularly in pipelines on
the suction side. When pumping viscous fluids use pipe runs with a bore several times
larger than the pump tube. Any valves in the pipeline (not usually needed) must not
restrict the flow. Any valves in the flow line must be open when the pump is running.
Do ensure that on longer tube runs at least 1m of smooth bore flexible tubing is con-
nected to the inlet and discharge port of the pumphead to help to minimize impulse
losses and pulsation in the pipeline. This is especially important with viscous fluids and
when connecting to rigid pipework.
Do site the pump at or just below the level of the fluid to be pumped if possible. This
will ensure flooded suction.
Do keep the pumphead track and all moving parts clean and free from contamina-
tion and debris.
Do run at slow speed when pumping viscous fluids. Flooded suction will enhance
pumping performance in all cases, particularly for materials of a viscous nature.
Do recalibrate after changing pump tubes, fluid, or any connecting pipework. It is
also recommended that the pump is recalibrated periodically to maintain accuracy.
When using Marprene or Bioprene continuous tubing, do re-tension the tube after
the first 30 minutes of running.
Tube selection: The chemical compatibility lists published in Watson-Marlow publica-
tions are guides. If in doubt about the compatibility of a tube material and the duty
fluid, request a Watson-Marlow tube sample card for immersion trials.

Watson-Marlow 323E, 323S, 323U and 323Du User Manual 17
We recommend using commercially available supply
voltage surge suppression where there is excessive elec-
trical noise.
E, S, U, Du 10 Connecting this product
to a power supply
A well regulated electrical mains supply is required along with cable connections con-
forming to the best practice of noise immunity. It is not recommended to site these
drives alongside “dirty” electrical mains supplies such as 3-phase contactors and in-
ductive heaters without special attention being paid to unacceptable mains-borne
noise.
The voltage selector is mounted in the switchplate at the rear of
the pump. Set the voltage selector to 115V for 100-120V
50/60Hz supplies or 230V for 200-240V 50/60Hz supplies. Al-
ways check the voltage selector switch before connecting the
mains supply. Make suitable connection to an earthed, single-
phase mains electricity supply. To comply with Safety Standards,
the mains plug must be a separable plug (not a locking type).
Input line fusing: type T1.0AH 250V 20mm time-delayed cartridge fuse, located in
the combined mains IEC inlet socket and fuse drawer at the rear of the pump.
Note: A spare fuse is also provided in the drawer.
Conductor coding
European North American
live brown black
neutral blue white
ground green/yellow green

Watson-Marlow 323E, 323S, 323U and 323Du User Manual 18
E, S, U, Du
E, S, U, Du 12 Switching the pump on
Switch on the power supply at the rear of the pump. The pump runs a power-on
test to confirm proper functioning of the memory and hardware. If a fault is
found, an error message is displayed. See 19 Error messages.
If the pump starts running look for the !symbol on the display. This ! symbol in-
dicates that the pump is set for auto-restart. Press the STOP key if you need to
stop the pump
11 Start-up check list
Ensure that proper connections are achieved between the pump tube and
suction and discharge piping.
Ensure proper connection has been made to a suitable power supply.
Ensure that the recommendations in section 9 Good pump installation practice
are followed.
Check the position of the voltage selector switch
Check the mains power switch at the rear of the pump
Check the fuse in the mains inlet socket at the rear of the pump
Ensure that the mains IEC plug is correctly fitted in the mains IEC inlet socket
First-time start-up defaults
323E 323S 323U 323Du
Direction Clockwise Clockwise Clockwise Clockwise
Pumphead, 400
Pumphead, 220
313 313
501RL
313
501RL
313
501RL
Keypad lock Off Off Off
Auto-restart Off Off Off
Pump status Stopped Stopped Stopped Stopped
Remote stop Open=run Open=run
The pump is now ready to operate according to the defaults listed above.
All operating parameters may be changed by means of key-presses. See 14 Manual
operation.

Watson-Marlow 323E, 323S, 323U and 323Du User Manual 19
Do not use auto-restart for more than 10 starts per hour.
We recommend remote control where a high number of
starts is required.
S, U, Du 13 Auto-restart facility
Auto-restart will restart the pump after mains power interruptions. The pump will re-
turn to its previous operating state. To install auto-restart:
Mains power must be available to the pump to engage auto-restart.
Stop the pump. Turn off the mains power switch at the rear of the pump.
Hold down the START key and turn the mains power switch on. The !symbol
will show on the display.
Start the pump. If the mains supply is interrupted the pump will automatically
restart when the mains power returns.
Auto-restart is retained while the pump is switched off.
To remove auto-restart switch off the mains power at the rear of the pump. Hold
down the STOP key and turn the mains power switch on. The !symbol will go
out.

Watson-Marlow 323E, 323S, 323U and 323Du User Manual 20
14 Manual operation
You can adjust the speed on the display while the
pump is stopped or running.
Use the UP key to increase the set speed. Use the
DOWN key to reduce the set speed. We recommend
that the speed is reduced to a minimum before start-
ing the pump.
The 323E increments in steps of 5rpm. The 323S,
323U and 323Du increment in steps of 1rpm.
Press the DIRECTION key to reverse the direction of
rotation.
The direction is shown by the rotation symbol. The di-
rection may be changed while the pump is stopped or
running.
Start the pump with the START key.
The rotation symbol will move to confirm that the pump is operating. The sym-
bol is static when the pump is stopped.
Stop the pump with the STOP key. The pump will stop immediately.
The display will continue to show the previous speed and direction. The pump
will return to this speed when the START key is pressed again.
You can reduce the pump speed to 0 rpm with the DOWN key. The pump is still
in the running state and the rotation symbol will continue to move. Press the UP
key to return the pump to the minimum speed.
E, S, U, Du