Stuart Turner Stuart SPU 130 Mini Guide

Installation, Operation & Maintenance
Instructions
Please leave this instruction booklet with the end user as it contains
important guarantee, maintenance and safety information
Read this manual carefully before commencing installation.
This manual covers the following products:
SPU 130 Mini
Pt. No. 46719
SPU 230 Mini
Pt. No. 46720
STUART
CE compliant product
2

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PRODUCT DESCRIPTION
Heating and cooling system pressurisation top up unit with integral water storage tank
and electric solenoid piston pump, automated control system consisting of pressure
transducer and water level switch. The tank includes an AB air gap for category 5 fluid
isolation (BS EN 1717).
APPLICATION
The SPU Mini range is designed to provide intermittent water top up only to
compensate for intermittent losses in system pressure in heating and cooling systems
in commercial or industrial applications. These could include slight leaks, air venting,
etc. The units are not designed to deal with sudden losses of system pressure due
to major water losses over extended periods. They are also not to be used for water
boosting applications.
STORAGE
If this product is not to be installed immediately on receipt, ensure that it is stored in a
dry, frost and vibration free location in its original packaging.
CONTENTS Page
Checklist ...........................................................5
Important Facts – read before commencing installation ......................6
Location ............................................................7
Key Features ........................................................9
Installation ..........................................................10
Electrical Installation ..................................................14
Commissioning ......................................................18
Operation ...........................................................22
Maintenance .........................................................23
Environment Protection . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .24
Technical Specification ................................................25
Trouble Shooting .....................................................26
Product Log .........................................................27
Guarantee ..........................................................30

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WARNINGS
zThis appliance must not be used for any other
application without the written consent of Stuart
Turner Limited.
zThis appliance can be used by children aged from
8 years and above and persons with reduced
physical, sensory or mental capabilities or lack of
experience and knowledge if they have been
given supervision or instruction concerning use of
the appliance in a safe way and understand the
hazards involved. Children shall not play with the
appliance. Cleaning and user maintenance shall not
be made by children without supervision.
zChildren should be supervised to ensure that they
do not play with the appliance.
zThis product should not be used for the supply of
water to more than one heating/cooling system at
a time.
zThe electrical installation must be carried out in
accordance with the current national electrical
regulations.
zThe electrical installation must be installed by a
qualified person.
zThe motor is not accessible in normal operating
mode. The unit must only be operated with the
front cover in place.
zThe electrical installation must be carried out in
accordance with the current national electrical
regulations and installed by a qualified person.
zIn the interests of electrical safety a 30 mA
residual current device (R.C.D. not supplied)
should be installed in the supply circuit. This may
be part of a consumer unit or a separate unit.
zThis appliance must be earthed via the supply
cord.

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Please read installation details carefully as they are intended to ensure this product
provides long, trouble free service. Failure to install the unit in accordance with the
installation instructions will lead to invalidation of the warranty.

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CHECKLIST
Note:
Your product may vary slightly from the picture above.
Item Description Qty Item Description Qty
SPU 1 Fill valve flow restrictor, blue 1
Front cover 1 Rubber hose sealing washer,
to be used with item C 1
Flexible hose, G ½ 15 mm
compression 1 Cable tie 2
M6 screw 1 Instruction book 1
Wall mounting plate 1
A
E
C
B
D
H
G
F
I
Fig. 1
IMPORTANT: With the appliance removed from its
packaging check for any damage prior to installation.
If any damage is found contact Stuart Turner Ltd within
24 hours of receipt.
A D
C
Front cover removed for clarity
B
E
Electrical
rating plate &
serial number
G
H
F

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1 IMPORTANT FACTS: READ BEFORE COMMENCING PUMP INSTALLATION
A Water storage capacity.
1.11 The SPU Mini has a usable water volume of approximately 2 litres; the length
of time the SPU takes to pressurise a system will be dependent on:-
The pressure differential between the cold fill and set pressures and also the
refill rate of the tank
1.12 Ensure the pumps are primed as described in the priming section before
starting, to avoid causing damage to the pump. See Section 6.20 Hydraulic
commissioning.
B Water temperature
This unit is designed to pump cold water only which should not exceed the
following values:
1.13 The maximum allowable water temperature is 23 oC (see Technical Section).
1.14 The minimum allowable water temperature is 4 oC.
C Pipework – General
1.15 Do not drill holes or put fastenings into the SPU Mini tank, this will cause
leakage.
1.16 Secure pipework: Ensure pipework to and from pump is independently
supported & clipped to prevent forces being transferred to inlet and outlet
branches of the unit. Do not secure pipework to the SPU Mini, this will cause
damage and possible leakage.
1.17 Flux: Solder joints must be completed and flux residues removed prior to SPU
Mini installation (flux damage will void any warranty).
1.18 Pipework design: Care should be taken in the design of pipework runs to
minimize the risk of air locks e.g. use drawn bends rather than 90obends.
1.19 DO NOT introduce solder flux to flexible hose, tank, pump or any
parts manufactured from plastic.
1.20 DO NOT allow contact with oil or cellulose based paints, paint
thinners or strippers, acid based descalents or aggressive cleaning
agents.
1.21 DO NOT bend the flexible hose beyond 90o. It must be installed as
detailed, DO NOT kink. See Installation Section 4.14.
D Plumbing installation regulations
1.22 The plumbing installation must comply with the current water and building
regulations.
1.23 The plumbing installation must be installed by a qualified person.
E System filling
1.24 The SPU Mini is NOT DESIGNED TO FILL THE SYSTEM FROM EMPTY.
It is only intended to top up the system after occassional water leakage.
Systems should be filled via a dedicated filling loop.

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2 LOCATION  GENERAL
2.11 Location: The SPU Mini must be located on a solid wall of sufficient
strength to support the filled weight of the SPU Mini, close to the
water source and a suitable overflow position (see Section 10 –
Technical Specification for filled weight). The SPU Mini must not be
installed in a loft space. It must also be considered that the noise
and vibration from the SPU Mini may be transmitted through the
structure it is sited on. Ensure the minimum clearance requirements
are followed to allow servicing of the unit.
2.12 Access and minimum clearance requirements: For emergencies
and maintenance the SPU Mini must be easily accessible and have
the minimum clearance around it as laid out in Fig. 2. Additional
access to the front of the unit will be required to operate the
keypad and view the display.
2.13 Protection: The SPU Mini must be located in a dry, frost free area.
2.14 Ventilation: Ensure an adequate air flow to cool the SPU Mini.
Separate the SPU Mini from other appliances that generate heat.
Do not block the vent holes on the front cover.
2.15 Water retention: Site the SPU Mini in a location where in the
unlikely event of a water leak, any spillage is contained or routed
to avoid electrics or areas sensitive to water damage. As part of
the AB airgap (CAT 5 fluid isolation) the SPU Mini has a weir type
overflow on the front, water will be discharged from this area in the
event of the failure of the inlet valve or non-return valve.
2.16 Supply inlet pressure: The water supply inlet pressure must not exceed 7 bar.
2.17 Ambient temperature: The SPU Mini must be sited in a location where the
ambient temperature does not drop below 4 °C or exceed 40 °C.
2.18 Pipework: For optimum performance inlet and outlet pipework must be a
minimum of 15 mm pipe.
300
500
300
150 150
Fig. 2

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2.19 Static outlet pressure: The static outlet head must be 3 metres below pump
maximum cold fill pressure (vertically above the appliance).
2.20 Noise: A flexible hose is supplied as standard which will minimise the
transmission of noise and vibration from the SPU Mini pump to the
pipework connected to the appliance outlet. However, care must be taken
when mounting the SPU Mini that any noise is not amplified through loose
panels or pipework.
2.21 Flexible hose: Only use the Stuart Turner hose supplied with the SPU Mini.
2.22 Isolating valves: Separate system isolating valves (non-restrictive) must be
fitted to allow easy service of the SPU Mini. Isolating valves must be mounted
where specified to allow the system isolation and removal of the SPU Mini if
needed. See Section 4.14 for installation details.

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3 KEY FEATURES
3.11 The SPU Mini comprises of the following main components:-
1. Moulded tank – Main body of the SPU, comprising of an integrated water
tank with warning pipe and weir overflow and mounting the solenoid
piston pumps, manifold and controller.
2. Pump assembly – One or two piston pump units mounted into the
moulded tank with vibration isolating rubber mounts.
3. Outlet manifold – Brass manifold with pressure transducer used to monitor
system pressure and connection to the pump(s)
4. Programmable controller – Stuart Turner designed, user set controller,
allowing system set up and easy alarm connection.
5. Wall mounting plate – Robust stainless steel wall mounting plate allowing
quick, easy installation and removal if needed.
6. Moulded cover – Moulded acrylic capped ABS cover retained to the
moulded tanks with Dual LockTM fastening system for quick and easy
access
3.12 Principle of operation: The pressurisation unit consists of a break tank and
one or two piston pumps. The break tank is supplied with mains water from
the left to a float valve and includes an overflow and weir to maintain an AB air
gap in the tank. The unit is connected to the heating/chiller system
via a flexible hose which can exit the unit on either the left or right. The
pumps are connected via a flexible hose to the tank via a rubber connector.
A pressure transducer monitors system pressure and if a reduction in system
pressure is detected, the controller runs the pumps until the system is re-
pressurised to the required pre-set level. If the unit only has a single pump
connected it will run on a 30 minutes on/30 minutes off basis until this level
is reached, if the unit is a twin pump model the pumps run in duty standby
mode (the controller will alternate which pump starts first to even the
wear on the pumps). The manifold is fitted with a non-return valve to ensure
system pressure is maintained once pressurised.
1Fig. 3
2
3
4
5
6

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4 INSTALLATION
4.11 Fill valve flow restrictor guidelines: Ensure side entry fill valve is fitted
with the correct filter and flow restrictor combination (dependant on the
mains water pressure) into the G ½ threaded tail as outlined below:
Coloured insert – To be used for water pressure between 1 and 4 bar
White insert – The SPU Mini is pre fitted with the white high pressure insert.
Change if the unit is slow to fill or the water pressure is low (below 4 bar).
4.12 Cold mains feed connection: The connection to the cold water mains inlet is
made using a suitable fitting to the G ½ male thread on the left hand side of
the SPU Mini. When tightening ensure the fill valve within the tank is not
rotated. If the valve is rotated it may not function correctly with the risk
of flooding. (Do not overtighten).
4.13 Wall plate fixing:
1. When installing the SPU Mini on a wall ensure suitable fixings for the wall
structure are used and are suitable to support the unit when fully
filled with water (see technical section for filled weights). The holes in the
wall plate are 6 mm in diameter, the maximum permissible screw head
height is 3 mm.
2. All holes in the wall mounting plate must have fixings used in them as per
the image below, do not leave out fastenings as this will compromise the
integrity of the wall plate.
3. Ensure you have sufficent room around the area you are mounting the SPU
Mini to allow installation, servicing and operation. See section 2.12.
4. Ensure wall plate is fixed to a flat vertical wall and the top of the plate is
horizontal.
Fig. 4
Fig. 5

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5. Retain the SPU Mini to the wall mounting plate using the single M6
retaining screw at the top of the wall plate.
6. Fit the plastic cover by pressing as indicated below with the palm of the
hand as until the Dual LockTM is heard to ‘click’.
Fig. 6
Fig. 7

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4.14 Pipework connections & guidelines:
1. Before connecting the SPU Mini to the system ensure that system flushing
has been performed correctly and all foreign matter, including pipe scale,
has been removed.
Note: Foreign material from the system coming into contact with the
expansion vessel bladder could cause premature failure of the expansion
vessel.
2. Isolating valves MUST be installed on the unit inlet and outlet, before
connection to the flexible hoses to allow the unit to be isolated if required.
The isolation valve on the outlet should be of a lockshield type. See
Fig. 10.
3. A drain valve must be fitted on the outlet of the SPU Mini before the
isolation valve. See Fig. 10.
4. The connection to the heating/chilling system is also made with the
supplied flexible hose and a 15 mm compression fitting. The hose is
made water tight with a sealing washer on assembly, nip tight to 4 to
5 Nm for water tight seal. (Do not overtighten).
5. The connection to the heating/chilling system can be made to the left
or right hand side by routing the flexible hose supplied as detailed below.
Fig. 9Fig. 8
Cable tie

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6. The flexible hose and any wiring can be retained in the desired position
using cable ties and the two metal cable retention points on the top left
and right of the SPU tank. See Figs. 8 & 9.
7. The warning pipe should be connected to a suitable drain via a tundish
enabling visual warning of an overflow condition. The overflow fitting is
designed to use 19 to 23 mm diameter plastic waste pipe or connect to
G ¾ threaded pipe. Ensure there is a demountable joint in the pipe to
allow the removal of the SPU Mini if needed.
8. Non-return valves, pressure reducing valves and RPZ valves MUST NOT
be installed between the SPU Mini and the heating/cooling system. These
devices will prevent the pressure sensor from reading the system pressure
and will lead to incorrect operation of the unit.
9. The SPU Mini should be connected to the system return header along with
the expansion vessels as specified in BS 7074. See Fig. 10.
4.16 Typical installation diagram:
4.17 Vessel sizing & location:
1. System expansion vessel sizing should comply with the BS 7074 Expansion
Vessel sizing calculation.
2. The pressurisation unit and expansion vessels should be connected to the
system at the same point, to provide a neutral pressure reading.
3. A lockshield valve and drain valve should be installed at the inlet of each
expansion vessel to allow for servicing.
Fig. 10
Fig. 11
SPU Mini
Warning
pipe
Drain
valve
Isolation valvesExpansion
vessel
Return
header
Lockshield
valve
Drain valve

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5 ELECTRICAL INSTALLATION  EARTHING
5.11 Regulations: The electrical installation must be carried out in
accordance with the current national electrical regulations and
installed by a qualified person.
5.12 Safety: In the interests of electrical safety a 30 mA residual current
device (R.C.D. not supplied) should be installed in the supply circuit.
This may be part of a consumer unit or a separate unit.
5.13 Before starting work on the electrical supply ensure power supply is
isolated.
5.14 DO NOT allow the supply cord to contact hot surfaces, including the
motor shell, pump body or pipework. The cord should be safely
routed and secured by cable clips.
5.15 Adjacent pipes: Adjacent suction and delivery pipes should be fitted with
earthing clamps in accordance with current regulations (Fig. 12).
5.16 Earthing: This appliance must be earthed via the supply cord.
5.17 Pipework: Copper or metallic pipework must have supplementary earth
bonding where the continuity has been broken by flexible hoses or plastic
components.
5.18 Additional earthing: Certain installations may require additional earthing
arrangements such as equipotential bonding. Reference should be made to
the relevant regulations concerning this subject to ensure compliance.
5.19 Connections: The SPU Mini must be connected to a dedicated fused spur via
a lockable isolator to avoid authorized disconnection.
5.20 The electrical connection must be made adjacent to (not behind) the SPU
Mini to allow disconnection of the electrical supply should the pump module
need to be removed for service or maintenance.
Earth continuity
connection
Fig. 12
Flexible
hose
Metallic
pipework
Metallic
pipework

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5.21 Wiring of connection unit:
WARNING: This appliance must be earthed.
The wires in the mains lead (supply cord) are coloured in accordance with the
following code:
Green and Yellow: Earth
Blue: Neutral
Brown: Live
As the colours of the wires in the mains lead of this appliance may not
correspond with the coloured markings identifying the terminals in your
connection unit proceed as follows:
zThe wire which is coloured green and yellow must be connected to the
terminal in the connection unit which is marked with the letter E or by the
earth symbol: or coloured green or green and yellow.
zThe wire which is coloured blue must be connected to the terminal which
is marked with the letter N or coloured black.
zThe wire which is coloured brown must be connected to the terminal
which is marked with the letter L or coloured red.
5.22 Boiler interlock safety function:
The SPU Mini is fitted with a single volt free contact specifically assigned for
boiler/chiller shut down in the event that the SPU Mini detects system
pressure above the Hi alarm pressure or below the Lo alarm pressure.
The boiler interlock contact will be open circuit below the Lo alarm pressure
and above the Hi alarm pressure.
When the system pressure is in its normal operating pressure range (above Lo
alarm pressure and below Hi alarm pressure settings) the contact is
closed circuit
Always refer to the boiler/chiller manufacturer’s instructions for correct
integration.

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5.23 Boiler interlock connections:
The circuit connected to the relay is limited to 5 Amps, 230 V a.c.
maximum. The Installer MUST fit a 5 Amp fuse in the circuit to the
alarm relay to protect the SPU Mini from damage.
For connection of output relays follow the steps and images below:
1) Remove the required green connector from the right hand side of the
control board.
2) Strip 6–8 mm insulation from the end of the connection wire (Max 1.5 mm2
CSA).
3) Insert wire into connector and screw down terminal screws to secure
(0.6 Nm max.).
NO
Boiler Interlock
Fig. 13
Fig. 14
Fig. 15
Fig. 16

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4) Re-insert connector into the correct location on the control board and route
the cable to the back of the SPU Mini and secure with a cable tie to the
retainer.
5.25 Supply cord replacement:
The supply cord and internal wiring within the terminal box are
routed and secured to ensure compliance with the electrical
standard EN 60335–1. It is essential that prior to any disturbance
of this internal wiring, all cable routing and securing details are
carefully noted to ensure re-assembly to the same factory pattern
is always maintained.
If the supply cord is to be changed or is damaged, it must be replaced with a
special cord assembly available from Stuart Turner or one of their approved
repairers.
On disassembly note the cord retention and routing system. Re-assemble to
the same pattern.
For information on cable connection consult the wiring diagram.
Model Fuse Size (AMPS)
All models 5
5.24 Fuses: The following fuse size should be used:
Fig. 17
Retainer
Cable tie

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6 COMMISSIONING
6.11 Pre-commissioning checklist:
Before starting the commissioning process the following conditions must be
met. If these conditions are not adhered to, damage to the equipment,
system and property may result.
zEnsure the unit is sited in a frost free area, away from precipitation and
water sprays/jets.
zAll necessary pipe/electrical connections should have been made to a
satisfactory standard by a qualified person.
zThe temperature and pressure at the point of connection are within the
operating limits of the pressurisation unit.
zThe heating/cooling system is fitted with a safety valve and expansion
vessel sized appropriately.
6.12 In order for the pressurisation unit and heating/cooling system to function
correctly the following conditions must be met. If these conditions have not
been met, the commissioning process should not continue.
zEnsure the system connection has been made into the heating/chiller
system return header.
zEnsure Non-return valves, pressure reducing valves or RPZ valves are NOT
installed between the pressurisation unit and the heating/cooling system.
zThe expansion vessel is pre-charged to the correct pressure (equal to
initial system design pressure).
6.13 Prior to commissioning, fill the heating/cooling system via a filling loop. The
SPU Mini is NOT designed to fill the system from empty, it is only intended to
top up the system after occasional water leakage.
zEnsure the heating/cooling system is filled and pressurised to the required
cold fill pressure, with the water at approximately ambient temperature.
zEnsure the system is dosed with a suitable corrosion inhibitor. Note the
SPU Mini is not designed for dosing chemicals into the system, this must
be done via other means.
6.14 Expansion vessel setting:
zTo set or check the expansion vessel charge pressure the lock-shield
valve between the SPU Mini and the vessel must be closed and the
vessel drained using the drain valve.
zA suitable gauge should be used to check the charge pressure.
zIf the charge pressure is too high it can be reduced by releasing air from
the vessel pre-charge valve or by using a pressure gauge with an integral
air release valve.
zIf the charge pressure is too low a small increase can be provided using a
car foot pump otherwise an oil free compressor or nitrogen bottle is
recommended.
zWhen the correct pressure is set the Schrader valve protective cap must
be replaced.
zCheck the integrity of the pipe-work. Ensure the lock-shield valve
between the system and the expansion vessel is open and the drain
valve is closed.

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6.15 Controller overview
The Stuart Turner SPU controller is designed to be intuitive to use and allows
functions and alarms to be set by the installer/user.
The functions are set using the 3 buttons (A, B, & C) on the front of the
controller and with the help of on screen prompts via the back lit LCD display.
On the front of the SPU a green ‘power on’ light will be displayed whilst the
unit is powered. If an alarm or error is raised the red ‘Error’ light will be
displayed.
A number pressure set points can be set using the menus, these set points are
detailed below, 1 to 4 and in the description of the function.
Button A Enters menus or selects values.
Button B Scrolls down through menus or reduces set values.
Button C Scrolls up through menus or increases set values.
TIME
PRESSURE
HIGH ALARM SET VALUE (1)
LOW ALARM SET VALUE (4)
SYSTEM PRESSURE SET VALUE (2)
DIFFERENTIAL SET VALUE (3)
PUMP 'OFF'
PUMP 'ON'
NORMAL OPERATION
SYSTEM
PRESSURE
Fig. 18
Fig. 19
AB C

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6.16 Function list & explanation
The functions are contained within an initial display and a settings menu.
6.17 Initial display
On start up, and during normal operation, if the SPU has had no button inputs
for 1 minute, the system pressure will be displayed (see Section 7.11).
6.18 Setting of SPU Mini see Fig. 19
To access the setting of the SPU Mini see the following procedure:
1 Press and hold button A for 5 seconds.
2 P1 will be displayed and the red Error light will slowly flash. See Fig. 20.
3 Using buttons B & C select the P function required.
4 Press button A to enter the function.
5 Using buttons B & C increment the value required up and down.
6 Press button A to confirm setting.
7 Press and hold button A until the red Error light stops flashing and the SPU
Mini reverts to normal operation. This operation will save the changed
values.
P1 System pressure (2)
see Fig. 18
Sets the required system pressure. Set in 0.1 bar
increments up to the maximum set value for the SPU
model. SPU 130 & 230, 4.0 bar max.
P2 Differential pressure (3)
see Fig. 18
Sets the pressure the SPU will turn on at as the system
pressure falls. Relative to the set system pressure. Set
in 0.05 bar increments below the System pressure (2),
cannot be set above 0.1 bar below the System pressure
(2).
P3 Hi Alarm (1)
see Fig. 18
Sets high system pressure alarm. Set in 0.05 bar
increments above the System pressure (2). Cannot be
set below System pressure + 0.5 bar. Alarm auto resets
when system pressure is reduced below alarm level.
If no button inputs are received within 1 minute the SPU Mini will revert to
normal operation and the red Error light will stop flashing.
Note – Pumps do not operate when in the setting menu.
The following functions can be set and modified:-
Fig. 20
AB C