Getinge Arjohuntleigh NIMBUS II User manual

Service Manual
NIMBUS II, NIMBUS 3, NIMBUS 3
PROFESSIONAL, DFS2 & DFS3

Nimbus/DFS Service Manual
Issue 2
April 2010 SER0001 Page i
Service Bulletins Incorporated
Bulletin Content Date
incorporated
SERB006 New Tubeset 151200 April 2010
SERB013 New Main PCB and modified wiring for USA Compressors April 2010
SERB024 Nimbus 3 Professional April 2010

Nimbus/DFS Service Manual
Issue 2
Page ii SER0001 April 2010

Nimbus/DFS Service Manual
Issue 2
April 2010 SER0001 Page iii
CHAPTER 1
Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1
About This Manual . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1
Warnings, Cautions and Notes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1
Technical Description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1
Operating Principle . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1
Dynamic Mode. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2
Static Mode . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3
Auto-Matt . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3
System Start Up Sequence . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4
Alternating Head Cells Modification . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4
CHAPTER 2
Maintenance. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1
Pump Maintenance Checks . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1
Pump Soak Times . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1
Pump Service . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2
Mattress Maintenance Checks . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2
Mattress Service . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3
CHAPTER 3
Pump Repair. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1
General. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1
Removing the Hanging Bracket . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3
Installing the Hanging Bracket . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3
Disassembling the Rear Case . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5
Assembling the Rear Case. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5
Disassembling the Pump Filter. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7
Assembling the Pump Filter . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7
Removing the Double Compressor Assembly . . . . . . . . . . . . . . . . . . . . . . . . . . 9
Installing the Double Compressor Assembly. . . . . . . . . . . . . . . . . . . . . . . . . . . 9
Removing the AV Mounts . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10
Installing the AV Mounts . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10
Replacing the Compressor Filters . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13
Removing the Compressor Bump Stops . . . . . . . . . . . . . . . . . . . . . . . . . . . . .13
Installing the Compressor Bump Stops . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13
Replacing the Shuttle Assemblies . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .15
Replacing the Coil Assemblies. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .15
Replacing the Manifold Gasket. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .17

Nimbus/DFS Service Manual
Issue 2
Page iv SER0001 April 2010
Removing the Rotary Valve Assembly . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19
Installing the Rotary Valve Assembly . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20
PCB Repairs . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 21
Interchangeability of Old and New Pumps and PCB Assemblies. . . . . . . . . . . . . . . . 21
Main PCB Assembly . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 22
General Repair Information. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 22
Specific PCB Configurations . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 22
Removing the Old Style Display PCB, PCB Transformer and Daughter Board (if fitted).. . . . 27
Removing the New Style Display PCB . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 29
Installing the New Style Display PCB Assembly . . . . . . . . . . . . . . . . . . . . . . . . 29
Removing the Front Panel . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 33
Installing the New Style Front Panel (if required) . . . . . . . . . . . . . . . . . . . . . . . . 33
Replacing the Mains/Power Inlet Socket and Cordset (Moulded Cordset Versions Only) . . . 35
Removing the Mains/Power Cable (Hard wired versions only) . . . . . . . . . . . . . . . . . 37
Installing the Mains/Power Cable (Hard wired versions only). . . . . . . . . . . . . . . . . . 37
Replacing the Mains/Power Fuses (All Versions). . . . . . . . . . . . . . . . . . . . . . . . 39
Replacing the Mains/Power Inlet Fuse Holders (Moulded Cordset Versions Only). . . . . . . 39
Removing the Mains/Power Fuseholders (Hard wired versions only) . . . . . . . . . . . . . 42
Installing the Mains/Power Fuseholders (Hard wired versons only) . . . . . . . . . . . . . . 43
Removing the Mains/Power Filter (Hard wired versons only). . . . . . . . . . . . . . . . . . 44
Installing the Mains/Power Filter (Hard wired versions only) . . . . . . . . . . . . . . . . . . 45
Removing the Mains/Power Fuseholders (Hard-wired pump with on-board mains/power filter) 47
Installing the Mains/Power Fuseholder (Hard-wired pump with on-board mains/power filter) . 47
Removing the Pressure Control Assembly . . . . . . . . . . . . . . . . . . . . . . . . . . . 49
Installing the Pressure Control Assembly. . . . . . . . . . . . . . . . . . . . . . . . . . . . 49
Removing the High Pressure Switch . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 51
Installing the High Pressure Switch . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 51
Replacing the Mains/Power Switch . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 53
Removing the 5-Way Connector and Support (Hard wired versions only) . . . . . . . . . . . 55
Installing the 5-Way Connector and Support (Hard wired versions only) . . . . . . . . . . . . 55
Replacing the Silencer Bag . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 57
Removing the Bio Filter (Nimbus 3 and DFS 3 Pumps Only). . . . . . . . . . . . . . . . . . 59
Installing the Bio Filter (Nimbus 3 and DFS 3 Pumps Only) . . . . . . . . . . . . . . . . . . 59
Changing the Battery . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 61
Replacing the Sounder . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 61
Replacing the Pump Case . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 62
Pump Label Sets . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 63
CHAPTER 4

Nimbus/DFS Service Manual
Issue 2
April 2010 SER0001 Page v
Mattress Repair . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1
General. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1
Removing the Top Cover. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3
Installing the Top Cover . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3
Removing the Base Cover . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3
Installing the Base Cover. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7
Replacing the Soft Foam Sheet . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9
Cell Replacement . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11
Removing a Cell . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11
Installing a Cell . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11
Removing the Manifold Assembly . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12
Installing the Manifold Assembly . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .12
Removing the Partial Non-Return Valve Assemblies . . . . . . . . . . . . . . . . . . . . . . 14
Installing the Partial Non-Return Valve Assemblies . . . . . . . . . . . . . . . . . . . . . . .14
Removing the Loop Sheet Assembly. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .15
Installing the Loop Sheet Assembly . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .15
Replacing the Elastic Loops (Nimbus 3/DFS 3 Only) . . . . . . . . . . . . . . . . . . . . . . 16
Removing the Sensor Pad Assembly . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17
Installing the Sensor Pad. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17
Removing the CPR Unit . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18
Installing the CPR Unit . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18
Replacing the Release Button - Old Connector version . . . . . . . . . . . . . . . . . . . . . 19
New Tubeset Assembly Components . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20
Repairing the Tubeset Connector Assembly. . . . . . . . . . . . . . . . . . . . . . . . . . . 21
Service Engineers Tubeset Assembly . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 25
Replacing the Tubeset . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 26
Replacing the CPR O-Rings . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .29
Replacing the Transport Assembly. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 29
Repairing the CPR Handle Sub-Assembly. . . . . . . . . . . . . . . . . . . . . . . . . . . . 29
Replacing the CPR Manifold Gasket. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 31
Alternating Head Cells . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 33
Installing the Alternating Head Cell Modification - Configuration 1. . . . . . . . . . . . . . . .33
Installing the Alternating Head Cell Modification - Configuration 2. . . . . . . . . . . . . . . .36
Nimbus 3 Professional Mattress . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .39
Removing the Profile Control Valve . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 43
Installing the Profile Control Valve . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 46
Removing the Knob and Rotor on a Vent Valve . . . . . . . . . . . . . . . . . . . . . . . . . 48
Installing the Knob and Rotor on a Vent Valve. . . . . . . . . . . . . . . . . . . . . . . . . . 51

Nimbus/DFS Service Manual
Issue 2
Page vi SER0001 April 2010
CHAPTER 5
Troubleshooting . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1
Troubleshooting Table . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1
CHAPTER 6
Testing. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1
Pump Flow, Pressure and Function Test . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1
Test Setup . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1
Power Fail Alarm Check . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2
Alarm Functions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2
High/Low Pressure Setpoint and Mute Mode Checks . . . . . . . . . . . . . . . . . . . . 2
Static and Dynamic Mode Pressure Tests . . . . . . . . . . . . . . . . . . . . . . . . . . 2
High/Low Pressure Setpoint Checks and Mute Mode Check using the Psion Organiser. . . . . 3
Psion Organiser Setup . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3
High Pressure Switch Setpoint Check . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3
Low Pressure Switch Setpoint Check . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3
Mute Mode Check . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4
High/Low Pressure Setpoint Checks and Mute Mode Check using the IR Interface Module. . . 4
IR Interface Setup . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4
High Pressure Switch Setpoint Check . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5
Low Pressure Switch Setpoint Check . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5
Mute Mode Check . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5
Static and Dynamic Mode Pressure Tests using the Psion Organiser . . . . . . . . . . . . . . 5
Static and Dynamic Mode Calibration Readings . . . . . . . . . . . . . . . . . . . . . . . 5
Adjusting the Pressure . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5
Psion Organiser Setup . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5
Static Mode Pressure Tests . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6
Dynamic Mode Pressure Tests. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7
Check Pump Serial Number . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8
Static and Dynamic Mode Pressure Tests using the IR Interface. . . . . . . . . . . . . . . . . 8
Static and Dynamic Mode Calibration Readings . . . . . . . . . . . . . . . . . . . . . . . 8
Adjusting the Pressure . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8
IR Interface Setup . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8
Static Mode Pressure Tests . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9
Dynamic Mode Pressure Tests. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9
Check Pump Serial Number . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10
Psion Organiser Setup . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11
IR Interface Setup and Passwords for ProNimbus . . . . . . . . . . . . . . . . . . . . . . . 11
Electrical Testing . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13

Nimbus/DFS Service Manual
Issue 2
April 2010 SER0001 Page vii
Electrical Safety Checks - Class I . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .13
Earth Continuity Tests . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .13
Mattress Pressure and Function Test . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14
Test Procedure . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14
CHAPTER 7
Technical Specification. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1
Pump . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1
Test standards . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1
Accessories . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2
Mattress . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3
Cover Specification. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4
Cleaning Symbols . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5
CHAPTER 8
Parts List. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1
Pump Assembly Parts List . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1
Mattress Assembly Parts List . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8
CHAPTER 9
Service Contact Details. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1

Nimbus/DFS Service Manual
Issue 2
Page viii SER0001 April 2010

Nimbus/DFS Service Manual Introduction
Issue 2 Chap 1
April 2010 SER0001 Page 1
CHAPTER 1
INTRODUCTION
1 About This Manual
ArjoHuntleigh strongly recommend that their equipment is only serviced by trained personnel
andprovidecoursesfor customers who wishto become licensed to servicetheir own equipment.
In no event will ArjoHuntleigh be responsible for any service performed by customers or third
parties.
This manual contains information on maintenance, servicing, repair, troubleshooting and testing for the
Nimbus®2, Nimbus 3, DFS 2, DFS 3 and Nimbus 3 Professional systems which comprise a pump
and a mattress. Read and understand this manual before attempting to service or repair the equipment.
Warnings, Cautions and Notes
WARNINGS given in this manual identify possible hazards in procedures or conditions which, if not
correctly followed, could result in death, injury or other serious adverse reactions.
Cautions given in this manual identify possible hazards in procedures or conditions which, if not
correctly followed, could result in equipment failure or damage.
Notes given in this manual are used to explain or amplify a procedure or condition.
WARNING: BEFORE PERFORMING ANY SERVICE OR MAINTENANCE PROCEDURES,
ENSURE THAT THE EQUIPMENT HAS BEEN ADEQUATELY
DECONTAMINATED.
VOLTAGES IN EXCESS OF 30 VOLTS RMS OR 50 VOLTS DC CAN, IN
CERTAIN CIRCUMSTANCES, BE LETHAL. WHEN WORKING ON
EQUIPMENT REQUIRING EXPOSURE TO LIVE, UNPROTECTED
CONDUCTORS WHERE SUCH VOLTAGES ARE PRESENT, EXTREME CARE
MUST BE EXERCISED.
2 Technical Description
The Nimbus 2, Nimbus 3, DFS 2, DFS 3 and Nimbus 3 Professional are Dynamic Flotation Systems
for use in aiding the prevention, treatment and management of pressure sores.
It is a powered, air-filled mattress replacement system with microprocessor-aided control and alarm
functions which have LED indication on the front panel of the pump.
Operating Principle
The patient is supported by twenty cells which are enclosed by a polyurethane coated fabric cover. This
cover has waterproof, vapour permeable, and two-way stretch properties.
The system incorporates a sensor that automatically adjusts the support pressure within the system to
accommodate different weight patients and their weight density or distribution. This sensor pad, known
as the Auto-Matt®sensor, optimises the pressure to which the cells are inflated to be the minimum to
support that patient in a given position.
Small adjustments can be made to the mattress pressure, using the comfort control knob on the pump.
This is a patient comfort feature to make small adjustments to the softness or firmness of the mattress.
The Nimbus 3 and DFS 3 mattress also includes the HeelGuard®special powered-down feature which
is designed to maximise pressure relief under the heels.

Introduction Nimbus/DFS Service Manual
Chap 1 Issue 2
Page 2 SER0001 April 2010
Dynamic Mode
In dynamic mode the support surface beneath the patient is cycled every 10 minutes providing periods
of pressure relief for the whole body.
Figure 1 and Figure 2 show how the system operates in dynamic and static modes. Figure 2 shows the
pneumatic circuit in principle. A dual compressor system is used to provide a source of air supply. This
is fed to a high pressure switch, the Auto-Matt sensor and a rotary valve. The high pressure switch is
used to detect system over-pressures through blockages. The low pressure switch, which is located in
the pressure control assembly, is used to detect if the air pressure in the system falls below minimum.
The rotary valve channels the air supply as shown below:
C to outlet A with B at atmosphere (D) - A & C Cells Inflated
C to outlet A and B - All Cells Inflated (A, B & C)
C to outlet B with A at atmosphere (D) - B & C Cells Inflated
C to outlet A and B - All Cells Inflated (A, B & C)
This then allows cells A and B in the mattress to be inflated and deflated in a cycle period of ten minutes.
Figure 1 - Mattress Cell Inflation Cycle
In the mattress there is a third section of cells labelled as C. These are fed through partial non-return
valves from cells A and B and are therefore never at zero pressure. These are positioned as shown in
Figure 1 to prevent the torso sectionfrom ‘bottoming’ during dynamic mode and when a patient is sitting
upright. Semi-dynamic pressure is also applied to the head cells (C) and the heel protector (above CPR
unit) for added patient comfort.
On Nimbus 3 and DFS 3, loop sheets, the heel cells have a special powered-down feature to facilitate
fast deflation and thereby improve pressure relief under the heels.

Nimbus/DFS Service Manual Introduction
Issue 2 Chap 1
April 2010 SER0001 Page 3
Static Mode
In static mode the support surface is kept constant and provides pressure reduction without cycling. The
rotary valve is held in a constant position so that cells A, B, C and the heel protector are equally inflated.
Figure 2 - Pneumatic System Diagram
Auto-Matt
TheAuto-Mattsensorconsistsofaflexibleairsensorpadwhichislocatedunderneaththemattresscells.
This acts as a pressure regulator and accommodates changes in patient weight and position in the
following manner:

Introduction Nimbus/DFS Service Manual
Chap 1 Issue 2
Page 4 SER0001 April 2010
It is pneumatically connected in parallel to the mattress cells and when it is not occluded it channels the
air supply away from the cells. Occlusion of the Auto-Matt sensor is by patient weight and position. In
this manner it allows internal mattress air pressures to be compensated to that required to support the
patient.
With no patient on the mattress the Auto-Matt sensor is not occluded and pressure in the mattress is
governed by the pressure control shown in Figure 2 . This is in turn set to a pressure range which can
be slightly adjusted to change mattress pressures for patient comfort.
With a patient on the mattress, pressure is exerted onto the cells and this can partially or totally occlude
the Auto-Matt sensor. This results in more air being supplied to the cells increasing their internal
pressure until full patient support is achieved. Should the patient change to a position which necessitates
a lower pressure, air is released via the Auto-Matt sensor through the pressure control valve until the
correct lower pressure is achieved in the cells.
System Start Up Sequence
After the pump is switched on the start up sequence is as follows:
• All display indicators illuminate for a few seconds.
• Low Pressure and Wait indicators remain illuminated while the mattress inflates (approx 20 Min). All
the other indicators go out.
• The pump runs one compressor until the rotor turns to the cross over position (within 5 Min).
• The rotor then depresses the microswitch which stops the rotor and activates the second
compressor.
• Both compressors run for 20 minutes or when the mattress reaches the minimum pressure setting.
• When the minimum pressure setting is reached the Low Pressure and Wait indicators go out.
• The pump cuts down to one compressor and the rotor starts to rotate.
• In Dynamic Mode the compressors will alternate every 4 hours.
• In Static Mode the Coils (4 off) will alternate every 4 hours (one at a time). The compressors
alternate depending on which coil is working (there are two coils in each compressor).
Alternating Head Cells Modification
The Nimbus and DFS beds arenormally supplied with the top three (head) cells configured so thatthey
are inflated to a specific pressure. Although the pressure in the head cells normally remains constant,
the pressure in the rest of the cells slowly alternates.
The Alternating Head Cells Modification converts the static head cells into alternating cells. The
modification can be applied in two configurations that follow:
Configuration 1 converts all three head cells from static pressure to alternating pressure.
Configuration 2 converts the second and third cells from static pressure to alternating pressure. The
top head cell remains as a static pressure cell.

Nimbus/DFS Service Manual Maintenance
Issue 2 Chap 2
April 2010 SER0001 Page 1
CHAPTER 2
MAINTENANCE
1 Pump Maintenance Checks
If any parts are found to be damaged they must be replaced in accordance with Chapter 3 “Pump
Repair”.
1.1 Visually inspect the following for damage, wear and potential faults:
1.1.1 Outer Casing Check for damage and security.
1.1.2 Switches, Control Knobs Check function.
1.1.3 Hanging Bracket Check for damage and security.
1.1.4 Outlet ports Check for damage and free from obstructions.
1.1.5 Rubber feet (8 Off) Check for security.
1.1.6 Fuses Check condition.
1.1.7 Front panel Check for damage to LED’s and buttons.
1.1.8 Mains/Power lead Check for damage and security of plug.
1.1.9 Labels Check all labels are present and legible.
1.2 Disassemble the Rear Case (Chapter 3, Page 5, Section 4) and visually inspect the following for
damage, wear, security and potential faults:
1.2.1 Compressor
1.2.2 Rotary Valve Assembly
1.2.3 Printed Circuit Boards (PCB’s)
1.2.4 Pressure Control Assembly
1.2.5 High Pressure Switch
1.2.6 Silencer Bag
1.2.7 Bio Filter (Nimbus 3 and DFS 3 Only)
1.2.8 Tubing and Wiring
1.2.9 Screws, Nuts and bolts
1.3 Remove the compressor lids and visually inspect the following for damage, wear and potential
faults:
1.3.1 Coils
1.3.2 Elbows and connectors
1.3.3 Filters and gaskets
1.3.4 Shuttle Valve Assemblies
2 Pump Soak Times
2.1 A pump must be soaked with its ports occluded for the following reasons:
• To ensure that the pump is at normal running temperature prior to pneumatic performance tests
being carried out.
• To stress test major/critical parts which have been replaced or repaired.

Maintenance Nimbus/DFS Service Manual
Chap 2 Issue 2
Page 2 SER0001 April 2010
2.2 All pumps should be soaked for a period of 30 to 60 minutes prior to any pneumatic performance
test being carried out.
2.3 If any of the following major/critical components have been replaced or repaired, then it is
recommended that the pump be soaked for 12 hours prior to being tested:
• Valve Shuttle Assemblies
• Silencer Bags
• Printed Circuit Boards (PCB’s)
• Compressor
• Rotary Valve Assembly
3 Pump Service
A pump should be serviced every 12 months or when the symbol is illuminated. To carry out a
service on the pump, do the following:
3.1 Carry out the Pump Maintenance Checks (Chapter 2, Page 1, Section 1).
3.2 Replace the following components:
3.2.1 Case Seal (Chapter 3, Page 5, Section 4 and Section 5 ).
3.2.2 Valve Shuttle Assemblies (Chapter 3, Page 15, Section 15).
3.2.3 Compressor AV Mounts (Chapter 3, Page 10, Section 10 and Section 11).
3.2.4 Compressor Filters (Chapter 3, Page 13, Section 12).
3.2.5 Case Filter (Chapter 3, Page 7, Section 6).
3.2.6 Pump Manifold Gasket (Chapter 3, Page 17, Section 17).
3.3 Reassemble the pump and soak for the recommended time (Refer to Page 1, Section 2).
3.4 Carry out a flow, pressure and function test on the pump in accordance with
Chapter 6, Page 1, Section 1 .
3.5 Carry out electrical tests on the pump in accordance with Chapter 6, Page 13, Section 8.
4 Mattress Maintenance Checks
If any parts are found to be damaged they must be replaced in accordance with Chapter 4 “Mattress
Repair”.
4.1 Visually inspect the following for damage, wear and potential faults:
4.1.1 Base and Top Cover Check for tears, staining, clarity of printed labels.
4.1.2 Base/Top Cover Zip Check the zip runs freely and condition of zip teeth.
4.1.3 Anti-slip pads Check for damage.
4.1.4 Fixing straps Check condition and security.
4.1.5 Loop sheet Check for broken/torn loops.
4.1.6 Sensor Pad Check condition and security of tubes.
4.1.7 Soft/Hard Foam Check condition.
4.1.8 Connectors Check for damage and security.
4.1.9 Tubing Check for security and ensure no kinks or twists.
4.1.10 Cells Check for damage and security.

Nimbus/DFS Service Manual Maintenance
Issue 2 Chap 2
April 2010 SER0001 Page 3
4.1.11 Manifold Check for damage and security.
4.1.12 Partial Non-Return Valves Check for condition.
4.1.13 Heel Protector Check for damage and security.
4.1.14 Pop Studs Check condition.
4.1.15 CPR Unit Check operation of Fast Deflate mechanism.
4.1.16 CPR Transport Knob Check operation.
4.1.17 CPR Inlet Manifold Check for damage and free from obstructions.
4.1.18 Tubeset assembly Check for damage and security of connection.
4.1.19 Alternating Head Cells If fitted, Check the security of all the connectors.
5 Mattress Service
To carry out a service on the mattress, do the following:
5.1 Carry out the Mattress Maintenance Checks (Refer to Page 2, Section 4).
5.2 Check the following components and replace if necessary:
5.2.1 CPR ‘O’ rings (Chapter 4, Page 29, Section 26 ).
5.2.2 CPR Manifold Gasket (Chapter 4, Page 31, Section 29).
5.3 Carry out an inflation test on the mattress in accordance with Chapter 6, Page 14, Section 9.

Maintenance Nimbus/DFS Service Manual
Chap 2 Issue 2
Page 4 SER0001 April 2010

Nimbus/DFS Service Manual Pump Repair
Issue 2 Chap 3
April 2010 SER0001 Page 1
CHAPTER 3
PUMP REPAIR
WARNING: BEFORE DISMANTLING THE PUMP, ENSURE UNIT HAS BEEN ISOLATED
FROM THE POWER SUPPLY BY REMOVING THE CORD PLUG FROM THE
WALL OUTLET.
1 General
This chapter details repair procedures for the Nimbus 2, Nimbus 3, DFS 2, DFS 3 and Nimbus 3
Professional pumps. All repairs should be carried out by ArjoHuntleigh approved service personnel.
After carrying out a service or any repairs, the pump must be soaked for the recommended time (Refer
to Chapter 2, Page 1, Section 2) and tested for serviceability. The table below defines the test
requirements which must be carried out following certain repairs:
To carry out a flow, pressure and function test on the pump, refer to Chapter 6, Page 1, Section 1.
To carry out the electrical tests on the pump, refer to Chapter 6, Page 13, Section 8.
Table 1 - Repair to Testing Requirments
Components / Assemblies Flow/Pressure & Function Test Electrical Safety
Compressor Yes Yes
Pressure Control Yes Yes
Gearbox Assembly Yes Yes
Silencer Bag Yes No
High / Low Pressure Switches Yes Yes
Shuttle Assembly Yes Yes
Coils Yes Yes
Elbows & Connectors Yes No
AV Mounts Yes Yes
PCB Yes Yes
Front Casing Yes Yes
Rear Casing No No
Battery No Yes
Switches No Yes
Fuses No Yes
Electrical Connectors No Yes
Mains/Power Lead No Yes

Pump Repair Nimbus/DFS Service Manual
Chap 3 Issue 2
Page 2 SER0001 April 2010
Figure 3 - Removing and installing the Hanging Bracket
Table 2 - Hanging Bracket Part List
Item Part Number Description Qty
10 151123 Hanging Bracket Assembly 1
20 151427 Bracket 1
30 151428 Wire 1
40 FAS046 Screw M3 x 10 CSK 2
50 FAS216 Nut M3 x 0.5 Euro Series 2