AUTOFLAME MM80006 User manual

04.08.2020
Combustion Management Systems
AUTOFLAME
SENSORS GUIDE

Autoflame Engineering Ltd.
Unit 1-2 Concorde Business Centre
Airport Industrial Estate
Wireless Road, Biggin Hill
Kent TN16 3YN
United Kingdom
Combustion Management Systems
[phone]
Tel:
[e-mail]
Email:
www.autoflame.com
Web:
AUTOFLAME
SENSORS GUIDE
04.08.2020
This manual and all the information contained herein is copyright of Autoflame Engineering Ltd. It may not be
copied in the whole or part without the consent of the Managing Director.
Autoflame Engineering Ltd’s policy is one of continuous improvement in both design and manufacture. We
therefore reserve the right to amend specifications and/or data without prior notice. All details contained in this
manual are correct at the time of going to print.

Important Notes
A knowledge of combustion related procedures and commissioning is essential before embarking work on any
of the MM/EGA systems. This is for safety reasons and effective use of the MM/EGA system. Hands on training
is required. For details on schedules and fees relating to group training courses and individual instruction,
please contact the Autoflame Engineering Ltd. offices at the address listed on the front.
Short Form - General Terms and Conditions
A full statement of our business terms and conditions are printed on the reverse of all invoices. A copy of these
can be issued upon application, if requested in writing.
The System equipment and control concepts referred to in this Manual MUST be installed, commissioned and
applied by personnel skilled in the various technical disciplines that are inherent to the Autoflame product
range, i.e. combustion, electrical and control.
The sale of Autoflame’s systems and equipment referred to in this Manual assume that the dealer, purchaser
and installer have the necessary skills at their disposal. i.e. A high degree of combustion engineering
experience, and a thorough understanding of the local electrical codes of practice concerning boilers, burners
and their ancillary systems and equipment.
Autoflame’s warranty from point of sale
•Two years on all electronic and electro-mechanical equipment, assemblies and components.
•One year on all EGA systems and UV & IR scanners, including parts, components, cells and sensors.
The warranty assumes that all equipment supplied will be used for the purpose that it was intended and in
strict compliance with our technical recommendations.
Autoflame’s warranty and guarantee is limited strictly to product build quality, and design. Excluded absolutely
are any claims arising from misapplication, incorrect installation and/or incorrect commissioning.

IMPORTANT SAFETY NOTES
Autoflame sensors must only be installed, wired, commissioned or
adjusted by an Autoflame trained and certified technician.
Any person installing, wiring, commissioning or adjusting the sensors
without undergoing proper Autoflame training and without full understanding of the Micro
Modulation (MM) system may put themselves and others in a seriously dangerous
situation that can result in serious injury or even death, and may cause permanent
equipment failure and substantial property damage.
Some of the wiring connections are live, make sure to totally and safely isolate the mains
power before undergoing any work related to the sensors. Failure to do so can result in
fatal injury.
It is the responsibility of the commissioning technician to ensure that all relevant Valve
Proving System (VPS) and air pressure proving standards are adhered to.
This guide must be read in conjunction with the relevant MM system manual.
!

Contents
1. AUTOFLAME SENSORS............................................................................................................... 6
2. GAS & AIR PRESSURE SENSORS (MK8 SERIES) .................................................................... 7
2.1. Installation........................................................................................................................................ 10
2.2. Mk8 MM Gas Pressure Sensor Applications................................................................................... 13
2.2.1. VPS / Pressure Limits with Vent Valve............................................................................. 13
2.2.2. VPS / Pressure Limits, No Vent Valve.............................................................................. 14
2.2.3. VPS / Pressure Limits with Vent Valve, Single Valve Pilot............................................... 14
2.2.4. VPS / Pressure Limits, No Vent Valve, Single Valve Pilot ............................................... 15
2.2.5. External VPS .................................................................................................................... 15
2.3. Mini Mk8 MM Gas Pressure Sensor Applications ........................................................................... 16
2.3.1. VPS / Pressure Limits with Vent Valve............................................................................. 16
2.3.2. VPS/ Pressure Limits, No Vent Valve............................................................................... 17
2.3.3. VPS / Pressure Limits with Vent Valve, Single Valve Pilot............................................... 17
2.3.4. VPS / Pressure Limits, No Vent Valve, Single Valve Pilot ............................................... 18
2.3.5. VPS Using Low Pressure Switch...................................................................................... 18
2.3.6. External VPS .................................................................................................................... 19
2.4. Valve Proving Time and Pressure Change ..................................................................................... 20
2.5. Combustion Air Pressure Proving ................................................................................................... 22
2.6. Draft Pressure Control – Mk8 MM ................................................................................................... 23
2.7. Gas / Air Pressure Monitoring with Mk8 DTI ................................................................................... 24
3. OIL PRESSURE SENSOR........................................................................................................... 25
3.1. Dimensions ...................................................................................................................................... 26
5.2. Installation........................................................................................................................................ 26
4. STEAM PRESSURE SENSOR .................................................................................................... 27
4.1. Dimensions ...................................................................................................................................... 28
4.2. Installation........................................................................................................................................ 29
5. TEMPERATURE SENSOR .......................................................................................................... 30
5.1. Dimensions ...................................................................................................................................... 32
5.2. Temperature Sensor’s Applications................................................................................................. 33
6. OUTSIDE TEMERATE COMPENSATION .................................................................................. 35
6.1. Outside Temperature Sensor .......................................................................................................... 37
6.2. Outside Temperature Compensation Module.................................................................................. 38
Annex: IP Ratings ............................................................................................................................... 40

1 Autoflame Sensors
Autoflame Sensors Guide Page | 6
1. AUTOFLAME SENSORS
Autoflame offers the following range of sensors for use with the Mk8 and Mini Mk8 MM systems:
•Air pressure sensors.
•Gas pressure sensors.
•Oil pressure sensors.
•Temperature sensors.
•Steam pressure (load) sensors.
•Outside temperature sensors.
The picture below illustrates some of the applications of these sensors on a steam boiler.
Steam Pressure
(Load) Sensor
Air Pressure Sensor
for Draft Control
Gas Pressure Sensor
(VPS / Gas Pressure Limits)
Combustion Air
Pressure Sensor

2 Gas & Air Pressure Sensors (Mk8 Series)
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2. GAS & AIR PRESSURE SENSORS (MK8 SERIES)
Gas pressure sensors can be used for the following purposes:
•Gas Valves Proving System (VPS) and/or gas pressure limits when used with an MM system.
•Gas pressure limits only when used with an MM system.
Air pressure sensors can be used for the following purposes:
•Combustion air pressure proving when used with an MM system.
•Draft pressure control when used with the Mk8 MM.
The gas and air pressure sensors can also be used for gas / air pressure monitoring application when used
with the Mk8 DTI.
Specifications
IP Rating
65
NEMA Rating
4
Check type
Self-check
Channels
Dual channel
Communication
Digital (RS485) and analogue
Max. Operating Temperature
85°C (185°F)
Min. Operating Temperature
-25°C (-13°F)
Housing
Aluminium
Wiring connection
2m (6.5ft) flying lead, pre-wired, screened
Installation
90° vertical (+/-10°)
Pressure measuring port
¼” parallel NPT / BSP female
Differential pressure port
1/8” parallel NPT / BSP female
Supplied with
¼” tapered NPT / BSP male nipple
Flying lead connector torque
1 to 3Nm max. tighten by hand only, do not over-tighten
Warranty
2 years limited warranty

2 Gas & Air Pressure Sensors (Mk8 Series)
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Gas and Air Pressure Sensors Range
Gas Pressure Sensors Range
Part #
Pressure Range
Zero Range
mbar
“wg
PSI
mbar
“wg
PSI
MM80006
±68
±27
±1
±1.36
±0.54
±0.02
MM80008
±344
±138
±5
±6.88
±2.76
±0.1
MM80011
±1034
±415
±15
±20.68
±8.3
±0.3
MM80012
±2068
±831
±30
±41.36
±16.62
±0.6
MM80014
±6894
±2770
±100
±137.88
±55.4
±2
Air Pressure Sensors Range
Part #
Pressure Range
Zero Range
mbar
“wg
PSI
mbar
“wg
PSI
MM80005
±68
±27
±1
±1.36
±0.54
±0.02
MM80013
±137
±55
±2
±2.74
±1.1
±0.04
ATEX Certified Gas and Air Pressure Sensors
An ATEX approved range of the gas and air pressure sensors is also available for use in
Hazardous Environments application where Explosion Proof equipment is required.
Classification: Ex Na IIC Gc
ATEX Certified Gas Pressure Sensors Range
Part #
Pressure Range
Zero Range
mbar
“wg
PSI
mbar
“wg
PSI
MM80006/EXP
±68
±27
±1
±1.36
±0.54
±0.02
MM80008/EXP
±344
±138
±5
±6.88
±2.76
±0.1
MM80011/EXP
±1034
±415
±15
±20.68
±8.3
±0.3
MM80012/EXP
±2068
±831
±30
±41.36
±16.62
±0.6
MM80014/EXP
±6894
±2770
±100
±137.88
±55.4
±2
ATEX Certified Air Pressure Sensors Range
Part #
Pressure Range
Zero Range
mbar
“wg
PSI
mbar
“wg
PSI
MM80005/EXP
±68
±27
±1
±1.36
±0.54
±0.02
MM80013/EXP
±137
±55
±2
±2.74
±1.1
±0.04

2 Gas & Air Pressure Sensors (Mk8 Series)
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Gas / Air Pressure Sensor’s Ports
The sensor has 2 pressure ports:
•Gas/ air pressure measuring port: used to measure the gas / air pressure.
•Differential pressure port: used as a reference to measure the atmospheric pressure, therefore it
should always be exposed to atmospheric pressure.
Gas / Air Pressure Sensor’s Selection
When selecting a gas pressure sensor for a specific application, it is necessary that the sensor’s measuring
range should be the closest to the gas pressure range of the application.
For example; a gas pressure sensor is required for the purpose of valve proving and gas pressure limits for a
boiler with maximum gas pressure supply of 170mbar, therefore MM80008 should be selected. MM80011,
MM80012, MM80014 or MM80006 should not be used.
Wiring Gas / Air Pressure Sensor to an MM
For the purpose of VPS, gas pressure limits and air pressure proving, the sensors can be wired as follows:
The screen wire on the flying lead is only used when connecting the sensor’s lead to the MM / DTI through a
terminal block, it must not be connected on the MM / DTI side.
Drawing and Dimensions
All dimensions in mm, 1 inch = 25.4mm.
Wire Colour
Mk8 MM Terminal
Mini Mk8 MM Terminal
Brown
RS485 -
31
29
Purple
RS485 +
32
30
Blue
0V DC
33
48
Red
15V DC
34
49
Screen
Do not connect at MM side

2 Gas & Air Pressure Sensors (Mk8 Series)
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2.1. Installation
The pressure sensor must be installed at a vertical angle, perpendicular to the gas/air flow direction.
When the gas pressure sensor is used for gas pressure limits or valve proving, the sensor should measure
regulated gas pressure, therefore it should be installed after the gas pressure regulator (governor).
It is recommended to connect the differential pressure port to atmospheric pressure outside the boiler house,
as the pressure inside the boiler house could differ from atmospheric pressure. this can be done by piping the
port to a vent inside the boiler house that is exposed to atmospheric pressure or using a pipe to connect the
port to the atmosphere outside the boiler house.
It is recommended to connect the gas sensor using a pigtail pipe to prevent moisture traveling to the sensor.
IP Rating of the Gas & Air Pressure Sensors
The gas / air pressure sensor is rated IP65 / NEMA 4, and can be safe for external use providing that the
following conditions are met;
•The flying lead is tightened according to specifications, over tightening the flying lead connector can
cause damage to the seal and therefore the IP65 rating will not apply.
•The sensor’s pressure measuring port should be connected to the gas pipe/air duct using tapered
thread NPT connector, PTFE tape should be used to seal the thread connection and the connection
must be tightened according to the specifications.
•The sensor’s differential pressure port should be piped using tapered thread NPT connector, PTFE
tape should be used to seal the thread and the connection must be tightened according to the
specifications, make sure this pipe is always dry / free from water, moisture and dust.
The gas pressure sensor is rated IP52 / NEMA 3 if the atmospheric pressure port is not piped, the supplied
plastic plug must be secured in place. Please check the Annex at the end of this manual for the explanation of
different IP ratings.
Figure 1.1. Correct Installation of the Gas Sensor

2 Gas & Air Pressure Sensors (Mk8 Series)
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Figure 1.2. Correct Installation of the Gas Pressure Sensor for IP65 / NEMA4 rating
IP52 installation – Differential Pressure port is not
piped (plastic cap must be placed)
IP65 installation – Differential pressure port is piped

2 Gas & Air Pressure Sensors (Mk8 Series)
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Air Pressure Sensor Differential Pressure
The Autoflame Air Pressure Sensor has a differential pressure port, this can be installed as shown below to
measure a differential pressure. This is necessary where the air pressure at low fire is below 1 mbar (0.4 "wg)
or when it is a local code requirement. It is also necessary if IP65 protection rating for the sensor is required
when using the sensor for outdoor applications for example.

2 Gas & Air Pressure Sensors (Mk8 Series)
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2.2. Mk8 MM Gas Pressure Sensor Applications
Autoflame Gas Pressure Senor can be used with the Mk8 MM for the purpose of Valve Proving System (VPS)
or Gas Pressure Limits or both at the same time.
The following options/parameters are related to the operation of the gas pressure sensor:
Option / Parameter
Mk8 MM
125
Fuel pressure sensor mode – fuel 1
126
Fuel pressure sensor mode – fuel 2
127
Fuel pressure sensor mode – fuel 3
128
Fuel pressure sensor mode – fuel 4
129
VPS operation
130
Gas valve configuration
132
Gas valve proving time
133
Maximum pressure change allowed during VPS
134
VPS valve opening time
136
Gas pressure switch – offset lower limit
137
Gas pressure switch – offset upper limit
Parameter 41
Gas pressure units
2.2.1. VPS / Pressure Limits with Vent Valve
Option /Parameter Option #
Setting for
VPS / Pressure Limits
Gas Pressure Limits
Fuel Pressure Sensor Mode
125 (Fuel 1)
1 - pressure Limits, Valve
Proving 2 - Pressure Limits
126 (Fuel 2)
127 (Fuel 3)
128 (Fuel 4)
Gas Valve Configuration 130
1 - Vent Normally Closed
2 - Vent Normally Open

2 Gas & Air Pressure Sensors (Mk8 Series)
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2.2.2. VPS / Pressure Limits, No Vent Valve
Option /Parameter Option #
Setting for
VPS / Gas Pressure Limits
Gas Pressure Limits
Fuel Pressure Sensor Mode
125 (Fuel 1)
1 - pressure Limits, Valve
Proving 2 - Pressure Limits
126 (Fuel 2)
127 (Fuel 3)
128 (Fuel 4)
Gas Valve Configuration
130
0 – No vent valve
2.2.3. VPS / Pressure Limits with Vent Valve, Single Valve Pilot
Option / Parameter Option #
Setting for
VPS / Gas Pressure Limits
Gas Pressure Limits
Fuel Pressure Sensor Mode
125 (Fuel 1)
1. pressure Limits, Valve
Proving 2. Pressure Limits
126 (Fuel 2)
127 (Fuel 3)
128 (Fuel 4)
Gas Valve Configuration 130
4. Vent Normally Closed, Single Valve Pilot.
5. Vent Normally Open, Single Valve Pilot .

2 Gas & Air Pressure Sensors (Mk8 Series)
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2.2.4. VPS / Pressure Limits, No Vent Valve, Single Valve Pilot
Option / Parameter Option #
Setting for
VPS / Gas Pressure Limits
Gas Pressure Limits
Fuel Pressure Sensor Mode
125 (Fuel 1)
1. pressure Limits, Valve
Proving 2. Pressure Limits
126 (Fuel 2)
127 (Fuel 3)
128 (Fuel 4)
Gas Valve Configuration
130
3. No Vent Valve, Single Valve Pilot.
2.2.5. External VPS
Autoflame gas pressure sensor is not used.
Option / Parameter Option # Setting for VPS
Fuel Pressure Sensor Mode
125 (Fuel 1)
3. External VPS
126 (Fuel 2)
127 (Fuel 3)
128 (Fuel 4)

2 Gas & Air Pressure Sensors (Mk8 Series)
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2.3. Mini Mk8 MM Gas Pressure Sensor Applications
If the Valve Proving System (VPS) facility is to be used then specific options/parameters must be set.
Option / Parameter
Mini Mk8 MM
125
Fuel pressure sensor mode – fuel 1
126
Fuel pressure sensor mode – fuel 2
128
VPS sensor type
129
VPS operation
130
Gas valve configuration
131
Gas pressure units
132
Gas valve proving time
133
Maximum change allowed during proving time
134
VPS valve opening time
136
Gas pressure switch – offset lower limit
137
Gas pressure switch – offset upper limit
138
Gas static line pressure lower limit offset
156
Terminal T82 function
2.3.1. VPS / Pressure Limits with Vent Valve
Option /Parameter Option #
Setting for
VPS / Pressure Limits
Gas Pressure Limits
Fuel Pressure Sensor Mode
125 (Fuel 1)
1. pressure Limits, Valve
Proving
2. Pressure Limits
126 (Fuel 2)
VPS Sensor Type
128
1. Pressure Sensor
Gas Valve Configuration 130
1. Vent Normally Closed
2. Vent Normally Open

2 Gas & Air Pressure Sensors (Mk8 Series)
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2.3.2. VPS/ Pressure Limits, No Vent Valve
Option /Parameter Option #
Setting for
VPS / Gas Pressure Limits
Gas Pressure Limits
Fuel Pressure Sensor Mode
125 (Fuel 1)
1 - pressure Limits, Valve
Proving
2 - Pressure Limits
126 (Fuel 2)
VPS Sensor Type
128
1. Pressure Sensor
Gas Valve Configuration
130
0. No vent valve
2.3.3. VPS / Pressure Limits with Vent Valve, Single Valve Pilot
Option / Parameter Option #
Setting for
VPS / Gas Pressure Limits
Gas Pressure Limits
Fuel Pressure Sensor Mode
125 (Fuel 1)
1. pressure Limits, Valve
Proving
2. Pressure Limits
126 (Fuel 2)
VPS Sensor Type
128
1. Pressure Sensor
Gas Valve Configuration 130
4. Vent Normally Closed, Single Valve Pilot.
5. Vent Normally Open, Single Valve Pilot .

2 Gas & Air Pressure Sensors (Mk8 Series)
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2.3.4. VPS / Pressure Limits, No Vent Valve, Single Valve Pilot
Option / Parameter Option #
Setting for
VPS / Gas Pressure Limits
Gas Pressure Limits
Fuel Pressure Sensor Mode
125 (Fuel 1)
1. pressure Limits, Valve
Proving
2. Pressure Limits
126 (Fuel 2)
VPS Sensor Type
128
1. Pressure Sensor
Gas Valve Configuration
130
3. No Vent Valve, Single Valve Pilot.
2.3.5. VPS Using Low Pressure Switch
Option / Parameter Option # Setting for VPS
Fuel Pressure Sensor Mode
125 (Fuel 1)
1. Valve Proving, Pressure Limits
126 (Fuel 2)
VPS Sensor Type
128
0. Mains Input
Terminal 82 Function
156
1. Valve Proving Mains Input
Note: During VPS, the input on terminal 82
should be on during the VPS air proving and
gas proving phases, and at all other VPS
phases, the input to terminal 82 should be
off. The pressure detected is the static line
pressure, so the pressure switch should be
set at a value just below this line pressure.
When the burner is firing, terminal 82 is not
checked.
Note: Void to boiler phase is done via
the pilot valve.

2 Gas & Air Pressure Sensors (Mk8 Series)
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2.3.6. External VPS
Option / Parameter Option # Setting for VPS
Fuel Pressure Sensor Mode
125 (Fuel 1)
1. Valve Proving, Pressure Limits
126 (Fuel 2)
VPS Sensor Type
128
0. Mains Input

2 Gas & Air Pressure Sensors (Mk8 Series)
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2.4. Valve Proving Time and Pressure Change
The following formulae may be used for calculating the proving time and pressure change allowed.
They are based on DVGW requirements of a leakage rate of 0.1% of the maximum volume flow.
Valve Proving Time:
= 4 ×  ×
÷1000+ 1
Vpt
Valve proving time in seconds.
Ip
Inlet pressure in millibars.
Pv
Pipe volume in litres (volume = πr2x length, total volume of any interconnecting pipe
between valve seals)
Mtp
Maximum gas throughput in litres per hour.
Pressure change:
= 0.25 ×()
Example
Valve proving time:
Inlet pressure
=
50 mbar
Pipe volume
=
5 litres
Max gas flow
=
100,000 litres per hour
= 4 ×  50 × 5
100,000 ÷1000+ 1
=14
Set option and parameter 132
=
15 seconds
Note: option 132 is set in increments of 5 seconds, values must be rounded up.
Pressure change:
Inlet pressure = 50 mbar
= 0.25 ×50 
Set option and parameter 133 = 12.5 mbar
Note: This is a metric formula, therefore imperial units must be converted before applying this calculation.
Conversion
PSI to mbar
Ft3to Litres
Ft3/hr to Litres
Multiplier
68.94.
28.31
28.31