BOSSCO AX1-2.5E Manual

Operation &
Maintenance Manual
BOSS Digital Pressurisation Equipment
AX Models (AX1-2.5E, AX2-2.5E, AX1-5E, AX2-5E)
PF Models (PF1-2.5E, PF2-2.5E, PF1-5E, PF2-5E)
Midi Models (MD1-2.5E, MD2-2.5E, MD1-5E, MD2-5E)
Digifiller (Digifiller 0.5, Digifiller 1.0, Digifiller 1.5, Digifiller 2.0)
Mini Models (MX1-3E, MX2-3E)

2
Contents
About this Manual 3
Conventions used in this Manual 3
Typography 3
Where to find more Information 3
Equipment Overview 4
Principal of Operation 4
Installation 5
Pipe Connections 5
Typical Installation Diagram 5
Flow Restrictors (Midi & Mini models only) 6
AX Skid Clearance and Connection Requirements 7
Pressfill (PF) Clearance and Connection Requirements 8
Midi (MD) Clearance and Connection Requirements 9
Mini (MX) Clearance and Connection Requirements 10
Electrical Power Supply 11
Fault Contacts 12
Power Filter 13
Commissioning 14
Pre-Commissioning Checklist 14
Controller Overview 15
Controller Programming 16
Hydraulic Commissioning 20
Commissioning Record 25
Operation 26
Fault Codes 26
Shutdown Procedure 27
Start-Up Procedure 27
Troubleshooting 28
Maintenance 31
Wiring Diagram 33
Service Log 34
Spares 36
Electrical Items (All Models) 36
AX Models (AX1-2.5E, AX2-2.5E, AX1-5E, AX2-5E) 37
PF Models (PF1-2.5E, PF2-2.5E, PF1-5E, PF2-5E) 38
Midi Models (MDE1-2.5, MDE2-2.5, MDE1-5, MDE2-5) 39
Digifiller Models (Digifiller 0.5, Digifiller 1.0, Digifiller 1.5, Digifiller 2.0) 39
Mini Models (MX1-3E, MX2-3E) 40

3
About this Manual
This Operation and Maintenance Manual contains all the necessary information to install,
commission, operate and maintain pressurisation equipment.
It is recommended to read all parts of this manual before undertaking any work on the equipment.
Conventions used in this Manual
This manual makes use of symbols to identify key pieces of information. Please take note of the
following symbols and their meaning:
DANGER –Important safety related information intended to prevent injury and/or
damage to the equipment, system or property.
CAUTION - Important information intended to prevent damage to the equipment,
system or property.
IMPORTANT - Important information intended to ensure that the equipment functions
correctly.
USEFUL –Useful information which may be helpful, but is not necessarily required for
the unit to function correctly.
Typography
This manual makes use of different typography to identify different types of information.
Italics Key words and phrases
(Round Brackets) Used to identify a button on the digital controller
[Square Brackets] A parameter on the digital controller
<Inequality Symbols> A message/fault code displayed on the digital controller
Where to find more Information
For further information please visit the BSS Website at: http://www.bssindustrial.co.uk/
BSS Technical (Leicester)
AMS Wigan
AMS Spares & Service (Nottingham)
Tel: [phone]
Tel: [phone]
Tel: [phone]
Email: [e-mail]
Email: [e-mail]
Email: [e-mail]

4
Equipment Overview
The function of this pressurisation unit is to provide a means of automated water top-up to sealed
heating and cooling systems. The equipment is designed to provide periodic water top-up to
compensate for minor losses in system pressure (e.g. slow leaks, air venting, etc.).
This equipment is not designed to cope with sudden losses of system pressure (e.g.
manual draining) or major water losses (e.g. large leaks). The equipment is also not
intended to be used for water boosting applications.
Principal of Operation
The following schematic shows the internal arrangement of a pressurisation unit:
The pressurisation unit is fitted with a break tank (1) which is filled from the mains water supply (2)
via a float operated valve (3). The break tank is fitted with an overflow (4) in case the break tank
overfills, and a weir overflow (5) in case the primary overflow fails.
The pressurisation unit is connected into the heating system (6) via an isolation valve (7).
The pressure sensor (8) monitors the system pressure.
If the pressure sensor detects a drop in pressure, the pump (9a) will pump water from the break tank
into the system. Once the required pressure has been reached, the pump will stop.
On twin pump models, a second pump (9b) is provided. The two pumps will run in a duty/standby
configuration (i.e. the active pump will alternate with each pump start).
The pump(s) are fitted with non-return valves (10a, 10b) to prevent backflow.
A drain valve (11) is provided for draining down the unit and for commissioning purposes.

5
Installation
This pressurisation unit is not designed to be installed in an outdoor environment. The
unit must be installed in a frost free environment, away from precipitation and water
sprays/jets. If there is a risk of flooding, the unit must be installed on a raised plinth.
Please refer to the appropriate datasheet for the maximum working pressure and
temperature of the pressurisation unit. The conditions at the point of connection to
the system must not exceed these values.
Pipe Connections
To avoid damaging the float valve, the mains water supply pipe must be flushed before
connection to the pressurisation unit.
All pipe connections must be made with appropriate jointing compound/PTFE tape.
If PTFE tape is used, care must be taken to ensure that the tape does not obstruct the
orifice of the fitting.
Non-return valves, pressure reducing valves and RPZ valves must not be installed
between the pressurisation unit and the heating/cooling system. These devices will
prevent the pressure sensor from reading the system pressure.
The pressurisation unit and expansion vessel should be connected to the system at the
same point, to provide a neutral pressure reading. This point of connection should be
in the system return, on the suction side of the circulation pump.
Typical Installation Diagram

6
Flow Restrictors (Mini, Midi & Digifiller models only)
Pressurisation equipment fitted with a plastic, side-entry torbeck valve must be fitted
with a filter and –depending on the mains water pressure –a flow restrictor. Failure
to do this may result in damage to the equipment.
Two different flow restrictors are supplied with the equipment, both of which include an integral
filter. The selection of the appropriate flow restrictor is based on the maximum mains water
pressure at the point of installation. Please refer to the following table for selection.
Mains Water Pressure
Requirement
1 –4 Bar
Low Pressure Restrictor (coloured)
Above 4 Bar
High Pressure Restrictor (white, factory fitted)
If no restrictor is required, the filter must be removed from one of the restrictors and installed on its
own. The following diagram shows how to remove the filter:
To install the flow restrictor/filter, hold it by the tab and push it into the opening of the float valve
connection, as shown in the diagram below:

7
AX Skid Clearance and Connection Requirements
Connection
Size
Notes
Mains
Water Feed
½” BSP M
An isolation valve must
be installed on the mains
water feed for servicing.
Break Tank
Overflow
22mm
Guidance on drainage
requirements should be
obtained from the local
water authority.
System
Connection
½” BSP M
/ 15mm
The pressurisation unit
and expansion vessel
should be connected to
the system at the same
point.
The point of connection
should be in the system
return, on the suction
side of the circulation
pump.
Non-return valves,
pressure reducing valves
and RPZ valves must not
be used.

8
Pressfill (PF) Clearance and Connection Requirements
Connection
Size
Notes
Mains
Water Feed
½” BSP M
An isolation valve must
be installed on the mains
water feed for servicing.
Break Tank
Overflow
22mm
Guidance on drainage
requirements should be
obtained from the local
water authority.
System
Connection
½” BSP M
/ 15mm
The pressurisation unit
and expansion vessel
should be connected to
the system at the same
point.
The point of connection
should be in the system
return, on the suction
side of the circulation
pump.
Non-return valves,
pressure reducing valves
and RPZ valves must not
be used.

9
Digifiller & Midi (MD) Clearance and Connection Requirements
Connection
Size
Notes
Mains
Water Feed
½” BSP M
An isolation valve must
be installed on the mains
water feed for servicing.
Break Tank
Overflow
22mm
Guidance on drainage
requirements should be
obtained from the local
water authority.
System
Connection
½” BSP M
/ 15mm
The pressurisation unit
and expansion vessel
should be connected to
the system at the same
point.
The point of connection
should be in the system
return, on the suction
side of the circulation
pump.
Non-return valves,
pressure reducing valves
and RPZ valves must not
be used.
Min 50mm

10
Mini (MX) Clearance and Connection Requirements
Connection
Size
Notes
Mains
Water Feed
½” BSP M
An isolation valve must
be installed on the mains
water feed for servicing.
Break Tank
Overflow
22mm
Guidance on drainage
requirements should be
obtained from the local
water authority.
System
Connection
¼” BSP F
The pressurisation unit
and expansion vessel
should be connected to
the system at the same
point.
The point of connection
should be in the system
return, on the suction
side of the circulation
pump.
Non-return valves,
pressure reducing valves
and RPZ valves must not
be used.
Min 50mm

11
Electrical Power Supply
This equipment must be electrically isolated before removing the covers. Cables
connected to the volt free contacts may be supplied from another source and may
remain live after the unit is isolated. These must be isolated elsewhere.
All electrical connections must be carried out by a suitably qualified and competent
person.
The mains power supply to the pressurisation unit must be connected into the fused terminal block
as shown below:
On some larger models, the fused terminal block is replaced by a fused spur. If this is the case, the
power supply must be connected into the fused spur, as shown below:
It is recommended to supply power to the pressurisation unit via a lockable isolator.
This should be installed within 2m of the equipment.
This equipment can be damaged by the high voltages produced by electrical
installation testing equipment. When performing electrical installation tests, the
equipment must be isolated from the supply.

12
Fault Contacts
There are 6 volt free fault contacts which can be used for connection to a BMS system, or as a boiler
interlock. These are terminals 1-12, located on the digital controller:
With the exception of the Common Alarm, it is possible to convert all other fault
contacts to normally closed. For further information please refer to the commissioning
section of this manual.

13
Power Filter
The digital controller can be adversely affected by EMI and power spikes. A power
filter may be required if the supply to the equipment is unstable (e.g. frequent power
cuts), shared by equipment which generates high levels of EMI (e.g. inverters, IT
equipment etc.) or is fitted with a backup generator.
If required, a power filter can be purchased separately using product code FC100.
The power filter must be connected between the transformer and the digital controller, on the
12VAC line, as shown in the diagram below:
Because the filter is installed on the secondary side of the transformer, the polarity of the
connections does not matter.
For the filter to function correctly, the “PE LINE” terminal must be connected to the
chassis common earth point

14
Commissioning
It is highly recommended to have this equipment commissioned by an AMS (BSS
Service Team on 0870 850 3886) approved engineer. Any damage or loss incurred
through incorrect commissioning by an unapproved engineer will not be covered by
the warranty.
Pre-Commissioning Checklist
The following conditions must be met before starting the commissioning process.
Failure to meet these conditions may result in injury or damage to the equipment,
system and property.
Equipment is sited in a frost free area, away from precipitation and water sprays/jets
All necessary pipe/electrical connections have been made to a satisfactory standard
The temperature and pressure at the point of connection are within the operating limits of
the pressurisation unit.
The heating/cooling system is fitted with a safety valve and expansion vessel
The following conditions must be met for the pressurisation unit and heating/cooling
system to function correctly. If these conditions have not been met, it is not advisable
to proceed with the commissioning process.
The system connection has been made into the system return header/pump suction
There are no non-return valves, pressure reducing valves or RPZ valves installed between the
pressurisation unit and the heating/cooling system
The expansion vessel is pre-charged to the correct pressure (equal to fill pressure)
It is advisable to fill the heating/cooling system prior to commissioning. If this is not
possible, the pressurisation unit can be used to fill the system after commissioning.
Depending on the size of the system, this may take a considerable amount of time.
The heating/cooling system is filled and pressurised to the required cold fill pressure, with
the water at ambient temperature (approximately).

15
Controller Overview
The following image shows the front of the pressurisation unit digital controller. 4 buttons are
provided for programming, and an LED display which shows scrolling messages.
When the controller is first powered up, it will display the controller version number.
This manual relates to controller version 6.3. If the controller is of a different version,
there may be differences in the menu items available.
Old Controller Design
On older models, the design of the digital controller is visualy different. The internal
components are identical and the button functions remain the same.
The old controller design is shown below:
When in normal operation, the controller will display the current system pressure. If a fault occurs,
the controller will display a fault code and produce an audible alarm.
In normal operation, the functions of the buttons are as follows:
Button
Function
Press
Hold
SET
-
Show Current System Pressure
MUTE
Mute Audible Alarm
Reset Unit
+
-
Enter Programming Menu
-
-
-

16
Controller Programming
Do not alter any settings without first understanding the implications of doing so.
Incorrect settings may cause damage to the equipment, system or property.
To enter the programming menu, hold the (+) button until “enter code” appears on the screen,
followed by “0000” with a flashing cursor after the first digit.
To gain access to the programming menu, one of the following codes must be entered:
Customer Code
Standard set of options
0823
Engineer Code (≥V6.3)
Extended set of options
4706
Engineer Code (<V6.3)
Extended set of options
0426
To enter the code, change the first digit with the (+) and (-) buttons, then press (SET) to move onto
the next digit. Repeat for all digits, then once the correct code is shown on the display, press (SET) to
enter the programming menu.
Once a correct code has been entered, the first option [COLD FILL] will appear on the screen.
Once in the menu, the value of the current menu item can be changed using the (+) and (-) buttons.
Once the current value has been set, pressing the (SET) button will move on to the next option.
It is not possible to navigate backwards through the menu. To return to a previous
setting in the menu, press the (SET) button repeatedly to scroll through to the end of
the menu, and then re-enter the appropriate code.
If the controller looses power while in the programming menu, all changes made will
be erased. To confirm all changes, the end of the menu must be reached, and the
“SAVING...” message must be displayed.

17
The table below gives details of all menu items, in the order that they will appear:
#
Menu Item
Function
Default
Value
1
COLD FILL
The required fill pressure, i.e. pump ‘cut-out’ pressure.
The recommended setting is 0.3 BAR above the static pressure
of the system (0.1 Bar per meter of static height).
For example, a 14m high installation will have a static pressure
of 1.4 Bar, making the recommended cold fill pressure 1.7 Bar.
It is not possible to enter a value higher than the current [HIGH
SET] or lower than the current [LOW SET] values.
1.0 Bar
2
HIGH SET
The high pressure alarm setting.
If the pressure in the system reaches this value, the <HIGH
PRESSURE> alarm and common alarm will be activated.
The recommended setting is 10% below the safety valve rating.
For example, if the safety valve rating is 3 Bar, the
recommended setting is 2.7 Bar.
It is not possible to enter a value lower than the current [COLD
FILL] value.
2.7 Bar
3
LOW SET
The low pressure alarm setting.
If the pressure in the system falls below this value, the <LOW
PRESSURE> alarm and common alarm will be activated, and the
pressurisation pumps will not run.
The recommended setting is 0.5 Bar below the [COLD FILL]
pressure.
It is not possible to enter a value higher than the current [COLD
FILL] value.
0.5 Bar
4
DIFFERENTIAL
The differential between the ‘cut-in’ and ‘cut-out’ pressures of
the pressurisation pumps.
The cut-in pressure will be equal to the [COLD FILL] pressure,
minus the differential pressure.
For example, if the [COLD FILL] pressure is set to 1.5 bar, and
the differential set to 0.2 Bar, the pump ‘cut-in’ pressure will be
1.3 Bar (1.5 –0.2 = 1.3)
0.2 Bar
5
FLOOD LIMIT
The maximum continuous run time for each of the
pressurisation pumps.
If a pump runs continuously for longer than this period, the
pump will stop and a <FLOOD LIMIT> alarm will be activated.
This is to prevent the unit from pumping large amounts of
water in the event of a large leak/burst pipe.
For very large systems, this may need to be increased.
The value can be changed in increments of 10 minutes, to a
maximum of 990.
10 MINS
6
PUMP 1 COUNT
The cumulative number of pump starts for pump 1.
This is a cumulative counter, the value of which cannot be
modified. If using the engineer’s code, the counter can be reset
to zero by holding the (MUTE) button.
-
7
PUMP 1 HOURS
The cumulative run time in hours for pump 1.
This is a cumulative timer, the value of which cannot be
modified. If using the engineer’s code, the counter can be reset
to zero by holding the (MUTE) button.
-

18
#
Menu Item
Function
Default
Value
8
PUMP 2 COUNT
The cumulative number of pump starts for pump 2.
This is a cumulative counter, the value of which cannot be
modified. If using the engineer’s code, the counter can be reset
to zero by holding the (MUTE) button.
-
9
PUMP 2 HOURS
The cumulative run time in hours for pump 2.
This is a cumulative timer, the value of which cannot be
modified. If using the engineer’s code, the counter can be reset
to zero by holding the (MUTE) button.
-
10
ALARM COUNT
The cumulative number of all alarm incidents.
This is a cumulative counter, the value of which cannot be
modified. If using the engineer’s code, the counter can be reset
to zero by holding the (MUTE) button.
-
11
POWER
INTERRUPTED
The cumulative number of power interruptions (i.e. controller
turned off/ power cut).
This is a cumulative counter, the value of which cannot be
modified. If using the engineer’s code, the counter can be reset
to zero by holding the (MUTE) button.
-
12
PULSE
When enabled, if a pump has been inactive for 60 days, it will
start and run for 2 seconds.
This is to prevent the pumps from seizing.
NO
13
EXCESSIVE
START
When enabled, if there are more than 3 individual pump runs
within an 8 hour period, the unit will register an <EXCESSIVE
DEMAND> alarm.
Enabling this option may cause false alarms on some systems.
NO
14
SERVICE
When enabled, a service reminder will be displayed after 12
months from when the option was enabled.
To reset the service reminder, set the value to ‘NO’ and exit the
menu. Then, re-enter the menu and set the value to ‘YES’ again.
NO
15
FILL SYSTEM
When enabled, the <LOW PRESSURE> and <FLOOD LIMIT>
alarms will be disabled, and pump 1 will run continuously for up
to 24 hours until the cold fill pressure has been reached.
Once the cold fill pressure has been reached, this option will
automatically be deactivated, and the low pressure alarm and
flood limit will be reactivated.
This function is used to fill a system that is empty or at low
pressure.
Care must be taken using this option as the flood limit alarm is
disabled, increasing the risk of flooding.
This option cannot be enabled on Mini pressurisation units.
NO
If using the customer code, the menu will end at this point. After pressing (SET) once
more, the controller will display “SAVING...” and return to normal operating mode. If
using the engineer’s code, additional menu items will be displayed.
The following settings are all pre-programmed in the factory and should not need to
be modified on site. If these settings appear to have been reset, the most likely cause
is a power spike. If this problem persists, a power filter may be required.

19
The following settings are for experienced engineers only. Incorrect configuration of
these settings can cause the equipment not to function correctly, and may cause
damage to the equipment, system or property.
#
Menu Item
Function
Default
Value
16
PUMPS NUMBER
The number of pumps installed in the pressurisation unit.
This can be set to either 1 or 2.
2
17
PUMP TYPE
The type of pump installed in the pressurisation unit.
There are two options, which are as follows:
0 –Centrifugal Pump
1 –Piston Pump (MX units only)
1
18
PUMP SENSE
Disabling this option will stop the controller from monitoring
the pumps and generating <PUMP FAIL> faults.
It is not recommended to disable this option. Please consult
Technical before doing so.
YES
19
SENSOR TYPE
The type of pressure sensor installed in the unit.
There are four options which are as follows:
0 –0-5V Output, 0-10 Bar Range
1 –1-6V Output, 0-10 Bar Range
2 –1-6V Output, 0-16 Bar Range
3 -
1
20
SPC
CONTROLLER
Enables the link to an SPC controller.
This option should only be enabled on pressurisation units
which are linked to an SPC controller, which are found on
automat equipment.
NO
21
GLYCOL UNIT
Enables the low glycol level switch.
This option should only be enabled on glycol pressurisation
units.
NO
22
ID NUMBER
A user configurable identification number.
This option does not serve any functional purpose.
12
23
RELAY
INVERSION
When enabled, all normally open fault contacts (i.e. all except
the common alarm) are converted to normally closed.
NO
24
OVERRUN
Allows the pump to continue running for a set period of time
after the required pressure has been reached.
This will prevent the pumps from ‘hunting’.
The value can be set from 0 –10 seconds.
5
25
PRESSURE
ALARM AUTO
RESET
When enabled, the <HIGH PRESSURE> and <LOW PRESSURE>
alarms will be cleared automatically if and when the pressure
returns to normal.
If disabled, the alarms must be manually reset.
YES
26
CASCADE
Allows the pumps to operate in duty/assist mode.
After either pump starts, the other pump will start after a set
period of time.
This option can be set to OFF, or 5 –30 seconds.
OFF
27
BOOST
When enabled, the controller will allowing the pumps to run
even if the system pressure is zero.
YES
28
FLOMAT
When enabled, the “high water” input is used to trigger a top
up solenoid valve connected to the “sensor healthy” volt free
contact.
This option should only be enabled on units which utilize a
solenoid valve as the means of top-up.
NO

20
Hydraulic Commissioning
1 –Float Valve Setting
Ensure that the break tank float valve is set to its lowest position:
AX & PF Units Min,i Midi & Digifiller Units
If a drain valve is fitted to the break tank, ensure that it is closed. Then, turn on the mains water
supply and allow the break tank to fill.
When the float valve operates for the first time, it may not close immediately, causing
the break tank to overfill. Once the internals of the valve have been fully wetted this
should not occur again.
2 –Bleeding Pumps
This step is only necessary for AX, PF, Digifiller and Midi units. For Mini units, move on to the next
step.
Make sure that the internal isolation valve within the pressurisation unit is closed by
following the steps below. Failure to do this may cause injury or damage to the
equipment, system or property.