Domnick Hunter Maxigas Series User manual

104 - 120
SERVICE GUIDE

EN
CONTENTS
1 Safety Information................................................................................................................................................................................................ 5
1.1 Markings and Symbols ........................................................................................................................................................................... 6
2 TECHNICAL SPECIFICATION.............................................................................................................................................................................. 7
3 Menu Interface ...................................................................................................................................................................................................... 9
ppm......................................................................................................................................................................................................................... 12
3 Servicing ............................................................................................................................................................................................................. 15
3.1 Cleaning....................................................................................................................................................................................................... 15
3.2 Service Intervals ......................................................................................................................................................................................... 15
3.3 Service Kits ................................................................................................................................................................................................. 16
3.4 Service Procedures .................................................................................................................................................................................... 17
3.4.1 Exhaust Silencer Replacement ............................................................................................................................................................. 18
3.4.2 Oxygen Sensor Replacement ............................................................................................................................................................... 18
3.4.3 Dust Filter Element Change .................................................................................................................................................................. 18
3.4.4 Outlet Flow valve replacement.............................................................................................................................................................. 19
3.4.5 Control Valve replacement.................................................................................................................................................................... 19
3.4.6 Inlet Valve Replacement ....................................................................................................................................................................... 20
3.4.7 Outlet Valve Replacement .................................................................................................................................................................... 21
3.4.8 Equalisation Valve Replacement .......................................................................................................................................................... 22
3.4.9 Exhaust Valve Replacement ................................................................................................................................................................. 23
3.5 Oxygen Analyser Calibration..................................................................................................................................................................... 24
4 Oxygen Analyser ................................................................................................................................................................................................ 25
E1 – Calibrate sensor..................................................................................................................................................................................... 26
E2 – Analogue output FSD ............................................................................................................................................................................ 26
E3 – Set 4 mA output ..................................................................................................................................................................................... 26
E4 – Set 20 mA output ................................................................................................................................................................................... 26
E5 – Sensor simulation .................................................................................................................................................................................. 27
E6 – Sensor selection .................................................................................................................................................................................... 27
E8 - Diagnostics ............................................................................................................................................................................................. 28
E9 - Restore ................................................................................................................................................................................................... 28
5 Troubleshooting ................................................................................................................................................................................................. 29
6 Service Record ................................................................................................................................................................................................... 31
APPENDIX A .......................................................................................................................................................................................................... 33

EN
5
1 Safety Information
Important: Do not operate this equipment until the safety information and instructions in this manual have been read and understood by all
personnel concerned.
Only competent personnel trained, qualified, and approved by domnick hunter should perform service and repair procedures.
Failure to observe this criteria nay invalidate the warranty.
Use of the equipment in a manner not specified within this manual may result in an unplanned release of pressure, which may cause serious
personal injury or damage.
When servicing, repairing and operating this equipment, personnel must employ safe engineering practices and observe all related
regulations, health & safety procedures, and legal requirements for safety.
Ensure that the equipment is depressurised and electrically isolated, prior to carrying out any of the procedures specified within this manual.
Most accidents that occur during the operation and maintenance of machinery are the result of failure to observe basic safety rules and
procedures. Accidents can be avoided by recognising that any machinery is potentially hazardous.
domnick hunter can not anticipate every possible circumstance which may represent a potential hazard. The warnings in this manual cover
the most known potential hazards, but by definition can not be all-inclusive. If the operator employs a procedure, item of equipment or a
method of working which is not specifically recommended by domnick hunter, ensure that the equipment will not be damaged or become
hazardous to persons or property.
Details of your nearest domnick hunter sales office can be found at www.domnickhunter.com
Retain this manual for future reference.

6
1.1 Markings and Symbols
The following markings and international symbols are used on the equipment:
Caution, Read the User Guide. Pressurised components on the system
Risk of electric shock.
Remote control. Generator may start
automatically without warning.
Wear ear protection Read the User Guide
Use a forklift truck
Conformité Européenne
NITROGEN (N2)
NITROX
DO NOT BREATHE
Asphyxiant in high concentrations. No odour. Slightly lighter
than air. Ensure adequate ventilation. Breathing 100%
nitrogen will produce immediate unconsciousness and death
due to lack of oxygen.
NON-FLAMMABLE COMPRESSED GAS
The following symbols are used within this user guide:
Highlights actions or procedures which, if
not performed correctly, may lead to
personal injury or death.
Highlights actions or procedures which, if
not performed correctly, could lead to
electric shock.
Highlights actions or procedures which, if
not performed correctly, may lead to
damage to this product.
When disposing of old parts always follow
local waste disposal regulations.

EN
7
2 TECHNICAL SPECIFICATION
MAXIGAS
Parameter Units 104 106 108 110 112 116 120
Inlet Air Quality ISO 8573.1: 2001 Class 2.2.1
Inlet Pressure barg
(psig)
6 – 10 and 10 - 18
(88 – 145) and (145 - 261)
Inlet Temperature
oC
(oF)
5 – 50
(41 – 122)
Port Connections
Air Inlet G1”
N2 Outlet to Buffer G1”
N2 Inlet from Buffer G1/2”
N2 Outlet G1/2”
Supply Voltage V ac
(50/60Hz) 100 – 240 ± 10%
Power W 38
Ambient Temperature
oC
(oF)
5 – 50
41 - 122
Humidity 50% @ 40oC (80% MAX ≤31oC)
IP Rating IP20 / NEMA 1
Pollution Degree 2
Installation Category II
Altitude m
(ft)
< 2000
(6562)
Noise dB(A) <75 <80

EN
9
3 Menu Interface
All of the operational parameters and data are accessed through the menu driven interface (refer to the menu map over the page). A breakdown
of the menus are as follows:
Menu 1 - Hours Meters
There are three hour meters available for viewing:
The time in hours that the generator has been producing gas.
The time in operating hours that the generator can produce gas before a service is required.
The time in hours that the generator has been operating in Economy mode.
Menu 2 – Fault Log
The fault log menu allows the user to access the 10 most recent fault messages.
Each fault is represented by a fault code and is displayed along with the run hours at which the fault
occurred. If a fault is active the fault code displayed will flash.
Any faults that are active when the power is switched off and are still active when the power is re-
applied will cause a new entry to be added into the fault log.
Fault Codes
C1 Pressure Start Inhibit
P1 Inlet Pressure Fault
P2 Pressure Sensor Fault
E1 Power Failure
Y1 O2 Alarm
Y2 O2 Communication failure
Y3 Incorrect cell selected
Y4 O2 high out of range
Y5 O2 zero drift error
S1 Service due
Menus 3 to 7 are all password protected. This is designed to prevent unauthorised access to all configurable parameters. The following access
levels have been assigned:
Access Level Password Pages Accessible:
User 1 1 2 3 _ _ 3
User 2 1 5 5 7 _ Enables MODBUS
Service 1 2 5 2 5 _ 1,2,3,4,5,6
Service 2 _ 1 4 0 9 1,2,3,4,5,6,7
To enter a password:
From the main operating menu press and hold both the and keys until the menu changes to
the password prompt as shown
The flashing cursor will be positioned over the first digit.
Using the key change the first digit of the code and press . The cursor will move to the next
digit.
Repeat the process and enter the following password 1 2 1 _ _ .
When the password has been entered correctly the Hour Meters menu will be displayed.
Use the key to navigate to the desired menu.

10
Menu Map

11

12
Menu 3 – Customer Settings :
Item Description Units Step Min Max Default
1 Oxygen alarm -- 1 0 1 0
2 Calibration Calibration software sub section
3 Oxygen alarm level See oxygen display settings
4 Oxygen alarm delay S 1 0 600 60
5 Start option enable -- 1 0 1 1
6 Economy enable -- 1 0 1 1
7 Fault relay on stop -- 1 0 1 0 = No
1 = Yes
8 Set Oxygen Analogue FSD See oxygen display settings
9 PPM Offset 0.1
10 Modbus Address -- 1 1 32 1
11 Remote control -- 1 1 3 1 = local
2 = digital IP
3 = remote com
Menu 4 – Service 1 : Setup
Item Description Units Step Min Max Default
1 Oxygen sensor type Ppm/% -- ppm % %
2 Production purity See oxygen display settings
3 Equalising/non equalising1-- 1 0 1 0 = Non Eq.
1 = Eq.
4 Oxygen sensor -- 1 0 1 0 = Digital
1 = RS232
5 Service enable -- 1 0 1 0 = off
1 = on
6 Service due at -- 100 0 999900 0
7 Clear fault log -- 1 0 1 0
8 Pressure sensor fitted -- 1 0 1 0 = Not fitted
1 = Fitted
9 Pressure sensor units Bar/PSI/MPa -- -- -- Bar
10 Eco Pressure Hi Bar/PSI/MPa 0.1 4.1 20 10.0 Bar
11 Eco Pressure Lo Bar/PSI/MPa 0.1 4 19.9 9.5 Bar
12 Economy period M 1 1 120 5
13 Economy over-ride -- 1 0 1 0 = disabled
1 = enabled
14 Economy over-ride period m 1 1 600 20
15 MODBUS status -- 1 0 1 0 = disabled
1 = enabled
Menu 5 – Service 2 : Timers
Menu Description Units Step Min Max Default
1 Hours run H 100* 0 999900 0
2 Hours economy H 100* 0 999900 0
3 Hours O2 vent H 100* 0 999900 0
*1 Hour increments for normal operation, 100 hour increments for adjustment

13
Menu 6 – Service 3 : I / O Menu
Item Description Units Step Min Max Default
1 Digital input summary -- -- 0000 1111 --
2 Digital output summary -- -- 000000000000 111111111111 --
3 Pressure sensor input Bar/PSI/MPa -- -- -- --
4 Pressure sensor 4mA offset MA 0.01 -0.10 +0.10 4.00mA
5 Pressure sensor mA gain mA 0.01 -0.10 +0.10 20.00mA
6 Pressure Sensor Span Bar/PSI/Mpa 0.1 4.0 25.0 20.0
7 Test buttons -- 1 0 1 0
Menu 7 - Service 4 : Customisation
Item Description Units Step Min Max Default
1 Inlet period S 1 10 600 See table
2 Exhaust period S 1 9 599 See table
3 Equilisation period S 0.5 0.5 5 See table
4 Inlet pressure delay S 1 0 600 60
5 Rapid start period S 1 10 600 40
6 Start clean up cycles (%) -- 1 1 10 2
7 Pure start A cycles (ppm) -- 1 1 10 2
8 Pure start B cycles (ppm) -- 1 0 10 1
9 Start delay S 1 0 60 0
10 Service period h 100 100 50000 8000
11 Factory reset -- 1 0 1 0
12 Total reset -- 1 0 1 0

EN
15
3 Servicing
The recommended Service procedures identified in table 3.2 and all other repair and calibration work should be undertaken by a domnick
hunter trained, qualified and approved engineer.
3.1 Cleaning
Clean the equipment with a damp cloth only and avoid excessive moisture around any electrical sockets. If required you may use a
mild detergent, however do not use abrasives or solvents as they may damage the warning labels on the equipment.
3.2 Service Intervals
Description Of Maintenance Required Typical Recommended Maintenance
Interval
Component Operation
Daily
2000 Hours
(3-month)
4000 Hours
(6-month)
80000 Hours
(12-month)
16000 Hours
(24-month)
Generator Check status indicators located on the control panel.
System Check inlet air quality
Generator Check for air leaks
Generator Check pressure gauges during purging for excessive
back pressure
Generator Check condition of electrical supply cables and conduits
Generator Check cyclic operation
Generator Replace active exhaust silencers
Recommended Service A
Filtration Replace dust and control air filters.
Recommended Service B
Generator Replace/Calibrate oxygen sensor
Recommended Service C
Generator Replace/Service valves
Recommended Service D
- Check – Replace
Typical Recommended Maintenance Intervals
Service 8 000 Hours
(12 Months)
16 000 Hours
(24 Months)
24 000 Hours
(36 Months)
32 000 Hours
(48 Months)
40 000 Hours
(60 Months)
A
B
C
D
domnick hunter ltd and its distributors offer a comprehensive range of preventative maintenance programmes, for further details
contact your local domnick hunter distributor or domnick hunter ltd direct (tel. [phone]) for further details.

16
3.3 Service Kits
Service Kit Description Kit No.
A – Silencer Service Exhaust Silencer Kit 608620090
B – Filter Service Filter Element Kit 020AR
PPM O2Cell Kit 606500002
C – O2Cell Service
% O2Cell Kit 606500003
PPM Valve Overhaul Kit (without equalisation valve) 606500004
D – Valve Service
% Valve Overhaul (with equalisation valve) 606500005
A
E
C
D
D
D

17
3.4 Service Procedures
It is essential that the generator is isolated from the mains power supply and fully
depressurised before carrying out any servicing procedures.
Stopping the equipment
Close the ball valve on the N2 Outlet port.
Press [ ] to initiate the shutting down sequence.
The generator will complete the current cycle and then exhaust both beds.
Observe the column pressure gauges on the side on the generator to ensure that they read 0bar.
When the generator is completely depressurised it will revert to standby mode.
Disconnect the generator from the electrical supply at the supply disconnection switch. Ensure that this switch is locked off to prevent
accidental operation.
Disconnect the compressed air supply from the generator.

18
Ensure that the generator is isolated from the mains power supply and fully depressurised before carrying out
any of the following service procedures.
3.4.1 Exhaust Silencer Replacement
The exhaust silencer is located under the inlet manifold assembly. Unscrew the silencer assembly from the exhaust flange plate and
remove.
Slide the silencer element off the baffle (A) and replace. Ensure that the replacement element is inserted into the groove of the baffle
end cap.
Screw the exhaust silencer assembly back into the exhaust flange plate.
3.4.2 Oxygen Sensor Replacement
Disconnect the O2cell lead from the O2 analyser. Terminals 1 & 2 (% vol O2cells) or 4 & 5 (ppm vol O2cells) (B)
Unscrew the tube nut holding the O2cell in place and remove the cell (C).
Fit the replacement sensor onto the t-piece and perform a leak test.
Refit the electrical connections to the O2analyser:
Terminal Function
1 -ve % vol sensor
2 +ve % vol sensor
3 Ground
4 -ve ppm vol sensor
5 +ve ppm vol sensor
Calibrate the sensor as detailed in section 4.7 (Note: PPM cells require the offset value to entered prior to calibrating)
3.4.3 Dust Filter Element Change
Close the buffer vessel outlet valve to isolate the housing and close the “Nitrogen outlet” valve.
De-pressurise the buffer vessel filter by opening the drain valve on the base of the filter. Observe the Nitrogen Outlet Pressure
Gauge, and wait for it to read zero.
If the filter is still pressurised, a high-pitched sound will be heard. If this occurs, stop this procedure
immediately and wait until the filter is completely de-pressurised.
Unscrew the filter bowl from the head (D) and remove the old filter element.
Holding the replacement element by the end caps, fit it into the bowl ensuring that the element is correctly seated (E).
Assemble the filter bowl onto the filter and tighten. The markers on the filter head and filter bowl must line up with each other when
fully assembled (F)
Close the drain valve on the filter and slowly open the outlet valve of the buffer vessel and the nitrogen outlet valve.
A B C
D E F

19
3.4.4 Outlet Flow valve replacement
The outlet flow valves are mounted on the outlet flow assembly.
Disconnect the solenoid plugs on both valves making a note of which plug
belongs to which valve.
Unscrew the 8 off M5 socket head cap screws that hold the valves in place and
remove.
Replace the valves taking care to ensure that the diaphragms and springs are
correctly orientated.
Secure the valves onto the manifold using the M5 screws.
Leak test the assembly and re-connect the solenoid plugs, remembering to
check for the correct orientation.
3.4.5 Control Valve replacement
The control valves are mounted on the back plate of the shroud as shown.
Make a note of the tubing and solenoid plug connections and remove them all.
Unscrew the four M5 screws holding the manifold onto the back plate and
remove.
If only one valve from the block is to be replaced, identify the valve and remove
the two screws on the rear of the manifold.
Replace the valve ensuring that the o-ring is in place.
Fit the manifold onto the back plate and re-fit the tubing and solenoid plugs.
Leak test the manifold block.

20
3.4.6 Inlet Valve Replacement
The inlet plate assembly is located above the lower manifold as shown.
Disconnect the inlet pipe-work, including the ball valve, from the port marked
“Compressed Air Inlet”.
Ensure that the pipe-work remains adequately supported whilst disconnected
from the generator.
Remove the tubing from the cylinders.
Whilst supporting the assembly, remove the 8 off M10 Hex HD bolts that hold
the inlet / outlet plate onto the strike plate.
Carefully withdraw the plate from the shroud and place it onto a clean surface.
Remove the remaining 1” BSP VSR plug from the plate.
Note: The plug may be located on either side of the plate depending upon which
side of the generator the outlet pipe-work is connected.
To remove the valve disc assemblies from the cylinders, insert a 10mm spanner
through the VSR plug hole onto the machined flat on the cylinder shaft.
With the cylinder shaft held securely, loosen the M6 Hex head stem bolt that
holds the discs onto the shafts.
Remove the cylinders from the inlet / outlet plate by unscrewing the M6 socket
head screws.
Replace the nose seal and fit the replacement cylinders to the plate
Torque the bolts down to 20Nm (15ft lb)
Assemble the valve discs onto the M6 x 25L stem bolts in the following order:
M6 anti vibration washer.
20mm ALU disc
31mm Poly disc
35mm ALU disc
Apply thread lock adhesive onto the stem bolts and then attach the valve disc
assemblies onto the cylinders.
Replace the 2 o-rings located in the machined grooves of the inlet / outlet plate
and re-attach the plate assembly to the strike plate using the 8 off M10 bolts.
Torque the bolts down to 34Nm (25ft lb)
Refit the 1” BSP VSR plug into the inlet / outlet plate assembly.
Reconnect the tubing to the cylinders.