Watson-Marlow 720UN User manual

Watson-Marlow 720UN and 720SN User Manual 1
WATSON-MARLOW BREDEL MANUALS
Watson-Marlow 720UN and 720SN pumps
m-720un-sn-gb-02
Contents
1 Declaration of conformity 3
2 Declaration of incorporation 3
3 Five-year warranty 4
4 When you unpack your pump 5
5 Information for returning pumps 6
6 Peristaltic pumps: an overview 7
7 Safety notes 8
8 Pump specifications 10
8.1 Dimensions 15
9 Good pump installation practice 16
9.1 General recommendations 16
9.2 Do’s and do not’s 17
10 Connecting this product to a
power supply 18
11 Start-up check list 19
12 Switching the pump on for the
first time 20
13 Switching the pump on in
subsequent power cycles
(if not in auto-restart mode) 22
14 Manual operation 23
14.1 Keypad functions 720UN 23
14.2 Keypad functions 720SN 26
14.3 Speed 29
14.4 Direction 29
14.5 Keypad lock 29
14.6 Keypad beep 30
14.7 To reset defaults 30
14.8 To reset language 30
14.9 Backlight 30
14.10 Auto-restart 31
14.11 Manual operation and
remote digital inputs
and outputs 31
15 Main menu 32
15.1 Keypad functions in
menu screens 32
15.2 Main menu entry 32
16 Setup 34
16.1 Trim 35
16.2 Analogue 36
16.2.1 Input speed 37
16.2.2 Trim 38
16.2.3 Menu 38
16.3 Display 39
16.4 Outputs 40
16.5 Remote stop 42
16.6 Auto-restart 44
16.7 Set maximum allowed
speed 45
16.8 Set minimum allowed
speed 45
16.9 Scrolling 46
16.10 Date and time 46
16.11 Backlight 47
16.12 ROM 47
16.13 Language 48
16.14 Defaults 48
16.15 Security code 49
16.16 Exit 50
17 MemoDose and calibration 51
17.1 Changing dosing speed 52
17.2 Footswitch operation and
other remote inputs and
outputs with MemoDose 53
17.3 Flow calibration 53
17.4 Exit 54
18 Exit 54
19 Automatic control wiring
using the 720N module 55
19.1 720N module removal and
replacement 55
19.2 Wiring up 56
19.3 Speed: analogue input 59
19.4 Speed: analogue output 60
19.5 Tachometer frequency
output 60
19.6 Run/stop input 61
19.7 Direction input 61
19.8 Auto / manual toggle
input 62
19.9 MemoDose input 62
19.10 Leak detection input 62
19.11 Outputs 1, 2, 3, 4 63
19.12 Supply voltages 63
20 Automatic control and operation 65
21 Troubleshooting 66
21.1 Error codes 67
22 Drive maintenance 68
23 Drive spares 68
24 720R, 720RX, 720RE and
720REX pumpheads installation 68

Watson-Marlow 720UN and 720SN User Manual 2
24.1 Pumphead do’s
and do not’s 68
24.2 720R, 720RX, 720RE
and 720REX
Key safety information 69
24.3 720R, 720RX, 720RE
and 720REX
safe-guarding 69
24.4 All 720R and 720RE
pumping conditions 69
24.5 All 720R and 720RE
pumpheads: fluid
management 69
25 Pumphead fitting 70
25.1 Removing and refitting
the pumphead 70
25.2 Removing and refitting
an extension pumphead 71
26 Tube loading 72
26.1 720R and 720RX
continuous tube loading 72
26.2 720RE and 720REX
LoadSure element loading 74
27 Pumphead spares: continuous
tubing models 720R and 720RX 75
28 Pumphead spares: LoadSure
element models 720RE and
720REX 76
29 Pumphead spares: rotor 77
30 720R and 720RE flow rates 78
31 720RE LoadSure element
product codes 79
32 720R continuous tubing product
codes 80
33 Trademarks 80
34 Warning not to use pumps in pa-
tient-connected applications 80
35 Publication history 80
36 Decontamination certificate 81

Watson-Marlow 720UN and 720SN User Manual 3
1 Declaration of conformity
This declaration was issued for Watson-Marlow 720UN and 720SN pumps
on May 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/CSA std
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
UN, SN
UN, SN

Watson-Marlow 720UN and 720SN User Manual 4
UN, SN 3 Five-year warranty
520 cased pumps, 620 cased pumps and 720 cased pumps
For any 520, 620 or 720 cased pump purchased after 1 January 2007, Watson-Mar-
low 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 five years
of the day of manufacture of the product. Such failure must have occurred 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.
620R pumpheads are consumable and excluded from all warranty when pump-
ing above 2 bar while above 165rpm.
Pumpheads from the 313/314 and the Microcassette ranges and any 701/720
extension pumpheads are excluded and retain their one-year standard pump-
head warranty. The drive they are attached to is subject to the five-year war-
ranty as set out here.
Ancillaries such as leak detectors are excluded.

Watson-Marlow 720UN and 720SN User Manual 5
UN, SN 4 When you unpack your pump
Note on lifting: The pump weighs more than 18kg (the exact weight depends on
model and pumphead—see 8 Pump specifications). Lifting should be performed ac-
cording to standard Health and Safety guidelines.
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
720UN and 720SN pumps are supplied as:
Dedicated 720 pump drive unit fitted with 720R, 720RE, 720RX or 720REX
pumpheads (see 8. Pump specifications).
A 720N module providing pump ingress protection to IP66, NEMA 4X.
Note: the module is attached for transit, but must be removed to allow wiring
up, voltage selection and fuse inspection and then re-affixed before the pump is
operated.
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 720UN and 720SN User Manual 6
UN, SN 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.
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 720UN and 720SN User Manual 7
UN, SN 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 720UN and 720SN User Manual 8
UN, SN 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.
There is a user-replaceable type T5A H 250V fuse
in the fuseholder in the centre of the switchplate
at the back of the pump. The 720N module must
be removed to allow access to the switchplate. See 19.1 720N
module removal and replacement. There are thermal fuses
within the pump which self-reset within 60 seconds; if they trip
an error code is displayed.
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.

Watson-Marlow 720UN and 720SN User Manual 9
There are moving parts inside the pumphead. Before opening the tool-un-
lockable track, ensure 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 the pumphead section of this manual: 24.
Secondary operator protection from rotating parts of the pump is provided by
indicator-only switching of the pumphead track. This function will stop the pump
if the track is inadvertently opened while the pump is running.
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.
Lifting
The unit weighs more than 18kg (the exact weight depends on model and pump-
head—see 8 Pump specifications). Lifting should be performed according to standard
Health and Safety guidelines.

Watson-Marlow 720UN and 720SN User Manual 10
UN, SN 8 Pump specifications
Labels fixed to the rear of the pump contain manufacturer and contact details,
product reference number, serial number and model details.
The same information is carried on the drive’s backplate, accessible when the 720N
module is removed. The number of connectors varies according to the model.

Watson-Marlow 720UN and 720SN User Manual 11
UN 720UN, IP66 NEMA 4X model
This pump can be controlled from the keypad or remotely. It features:
Manual control
Speed adjustment; run and stop; direction control; keypad scaling; “max” key
for rapid priming.
Remote control
The pump can be digitally controlled with a contact closure or logic input signal.
Analogue control
The pump speed can be controlled through an analogue signal input in the
ranges 0-10V, 1-5V or 4-20mA.
Outputs
A 0-10V or 0-768Hz output signal provides feedback of the pump speed. There
are four relay status outputs which can be configured in software for a variety of
pump parameters.
MemoDose
Allows repeat dosing. Stores in memory a pulse count from the motor. This
count is repeated each time START is pressed to provide a single-shot dose.
Calibration
Uses the same pulse count as MemoDose. The corresponding pumped volume
can be entered to calibrate the flow of the pump.
Guard switch
Primary operator protection from rotating parts of the pump is provided by the
pumphead track. Secondary operator protection from rotating parts of the pump
is provided by indicator-only switching of the pumphead track.
720SN, IP66 NEMA 4X model
This pump operates by manual control only. There are no external control connec-
tions. All pump functions are controlled from the keypad. It features:
Manual control
Speed adjustment; run and stop; direction control; "max" key for rapid priming.
MemoDose
Allows precise repeat dosing. Stores in memory a pulse count from the motor.
This count is repeated each time START is pressed to provide a single-shot
dose.
Calibration
Uses the same pulse count as MemoDose. The corresponding pumped volume
can be entered to calibrate the flow of the pump.
Guard switch
Primary operator protection from rotating parts of the pump is provided by the
pumphead track. Secondary operator protection from rotating parts of the pump
is provided by indicator-only switching of the pumphead track.
SN

Watson-Marlow 720UN and 720SN User Manual 12
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
* 720N cased pumps are rated to NEMA 4X (indoor use) only.
UN, SN
Unit weight
Drive only + 720R, 720RE + 720RX, 720REX
IP66 NEMA 4X 18.5kg, 40lb 13oz 25kg, 55lb 2oz 31.5kg, 69lb 7oz

Watson-Marlow 720UN and 720SN User Manual 13
Control range (turndown ratio) 0.1-360rpm (3,600:1)
Supply voltage/frequency Filtered 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 350VA
Full load current <1.5A at 230V; <3.0A at 115V
Eprom version Accessible through pump software
Enclosure rating - 720UN, 720SN
IP66 to BS EN 60529; Equivalent to
NEMA 4X to NEMA 250* (indoor use).
Suitable for heavy industrial, process and
dirty environments. The drive uses a
Gore membrane vent to equalise the
pressure inside the enclosure and to
prevent ingress of water and corrosive
vapours.
Pumphead options 720R, 720RE, 720RX, 720REX
Operating temperature range 5C to 40C, 41F to 104F
Storage temperature range -40C to 70C, -40F to 158F
Maximum altitude 2,000m, 6,560ft
Humidity (condensing) (720DuN) 10% - 100% RH
Weight See table on previous page
Noise <85dB(A) at 1m
Max peak pressure rating † 2 bar (30 psi)
Pump specifications
* Protect from prolonged UV exposure.
† For all tube materials including STA-PURE.

Watson-Marlow 720UN and 720SN User Manual 14
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 4X to NEMA 250 (indoor use) for IP66 products only
Standards

Watson-Marlow 720UN and 720SN User Manual 15
8.1 Dimensions
Drive only + 720R, 720RE + 720RX, 720REX
IP66 NEMA 4X 18.5kg, 40lb 13oz 25kg, 55lb 2oz 31.5kg, 69lb 7oz
Unit weights
242mm86mm 180mm
346mm
65mm164mm 186mm
508mm
160mm
305mm
280mm
221mm
61mm
150mm
658mm

Watson-Marlow 720UN and 720SN User Manual 16
UN, SN 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.
Do not stack other 720 pumps on top of this pump. It is, however, acceptable to stack
other equipment on the upper surface of the 720 (as long as the ambient tempera-
ture 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.
Connecting pipework
When using elements in a 720RE or 720REX pumphead, ensure that at least 600mm
(2ft) of the connecting pipework rises as it approaches the pumphead on both the
inlet and discharge sides. This helps the sliders which hold the element in place
to find their optimum position. Failure to do this may result in premature element
failure.

Watson-Marlow 720UN and 720SN User Manual 17
9.2 Do’s and do not’s
Do not build a pump into a tight location without adequate airflow around the pump.
Do ensure that when the 720N watertight module is fitted the seals are intact and
properly located. Ensure that the holes for cable glands are properly sealed to main-
tain the IP66 / NEMA 4X rating.
Do not strap the control and mains power cables together.
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.
IP66 / NEMA 4X models may be hosed down, but should not be immersed. Protect
from prolonged UV exposure.
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 publi-
cations 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.
Do not run the pump with no tube or element fitted to the pumphead. If the direc-
tion is changed, the rotor will continue turning as it tries to reverse and the software
will flag an error condition.

Watson-Marlow 720UN and 720SN User Manual 18
UN, SN 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 inductive 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, protected from water by the
720N module. The module must be removed to allow
access to the switchplate. See 19.1 720N module re-
moval and replacement. Set the voltage selector to
115V for 100-120V 50/60Hz supplies or 230V for
200-240V 50/60Hz supplies. Always check the volt-
age selector switch before connecting the mains sup-
ply. Make suitable connection to an earthed,
single-phase mains electricity supply. To comply with
Safety Standards, the mains plug must be a separa-
ble plug (not a locking type).
We recommend using commer-
cially available supply voltage
surge suppression where there
is excessive electrical noise.
Power cable: The pump is supplied fitted with either of two cable glands and ap-
proximately 2.8m of power cable. The European cable is to Harmonised code H05RN-
F3G0.75, used with our gland part number SL0128 which is suitable for an outside
cable sheath diameter of 4-7mm. The north American cable is to type SJTOW 105C
3-18AWG VW-1 used with our gland part number SL0123 which is suitable for an out-
side cable sheath diameter of 7-9mm.
Power cables of NEMA 4X specification pumps are fitted with a standard US mains
power plug. IP66 specification pumps are supplied with no plug. Wiring a mains plug
must only be undertaken by suitably skilled, qualified personnel.
European North American
line brown black
neutral blue white
ground green/yellow green
Conductor coding

Watson-Marlow 720UN and 720SN User Manual 19
The voltage selector switch is not visible while the
720N module is in place. Do not switch the pump on
unless you have checked that it is set to suit your
power supply by removing the module and inspecting
the switch, and then refitting the module. See 19.1 720N
module removal and replacement.
If the mains power cable is inappropriate for your installation, it can be changed.
Please contact your local Watson-Marlow Bredel service centre.
Input line fusing: type T5A H 250V
20mm time-delayed cartridge fuse, lo-
cated in a fuseholder in the centre of the
switchplate at the rear of the pump.
Power interruption: This pump has an
auto-restart feature which, when active,
will restore the pump to the operating
state it was in when power was lost. See
16.6 Auto-restart.
Stop / start power cycles: Do not
power up/power down for more than
100 starts per hour, whether manually
or by means of the auto-restart facility.
We recommend remote control where a
high number of starts is required.
UN, SN 11 Start-up check list
Note: See also 26, Tube loading.
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.

Watson-Marlow 720UN and 720SN User Manual 20
UN, SN 12 Switching the pump on
for the first time
Note: This manual uses bold type to highlight the active option in menu screens:
“English” in the first screen represented here. The active option appears on the pump
display in inverse text.
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 21.1 Error codes.
The pump displays a language menu. Use the UP and DOWN keys to select
your language. Press the ENTER key to confirm your choice.
The information which follows assumes that your choice was English.
When the language is chosen this menu will not appear again and all menus will
appear in the language you chose. (Language can be reset as described later.
See 16.13 Language.)
The pump displays the Watson-Marlow start-up screen for four seconds,
followed by a warning screen for four seconds (an example is shown here), and
then the manual mode main screen.
The rotation symbol on the display indicates clockwise rotation. The default
speed setting is 300 rpm, but 360 rpm is available (see 16.7 Set maximum al-
lowed speed). Other initial start-up operational parameters are listed in the
table below.