Oldham MX 52 User manual

COMMISSIONING, OPERATING
AND MAINTENANCE MANUAL
MX 52
MEASURING UNIT
Part Number: NP52UGB
Revision: B.0
The Fixed Gas Detection Experts

2
Copyright April 2016 by Oldham S.A.S.
All rights reserved. The reproduction of all or any section of this document in any form whatsoever
without the written permission of Oldham S.A.S. is forbidden.
The information contained in this manual is accurate to our knowledge.
As a result of continuous research and development, the specifications of this product may be modified at
any time without prior notice.

3
GAS DETECTION
We are delighted that you have chosen an OLDHAM instrument and would like to thank you for your
choice.
We have taken all the necessary measures to ensure that your instrument provides total satisfaction.
Now it is important to read this document carefully.
E
EX XT TE EN NT T O OF F R RE ES SP PO ON NS SI IB BI IL LI IT TY Y
* OLDHAM declines its responsibility towards any person for material damage, physical injury or death resulting
wholly or partly from inappropriate use, installation or storage of its equipment resulting from failure to observe
instructions and warnings and/or standards and regulations in force.
* OLDHAM neither supports nor authorises any company, physical or moral person to assume responsibility on
behalf of OLDHAM , even if it is involved in the sale of OLDHAM products.
* OLDHAM cannot be held responsible for direct or indirect damage or be required to pay direct or indirect
compensation resulting from the sale or use of any of its products IF THESE PRODUCTS HAVE NOT BEEN
DEFINED AND CHOSEN BY OLDHAM FOR THEIR SPECIFIC USE.
C
CL LA AU US SE ES S C CO ON NC CE ER RN NI IN NG G P PR RO OP PE ER RT TY Y
* Drawings, plans, specifications and information included in this document contain confidential information that is
the property of OLDHAM
* None of this information may be reproduced, copied, divulged or translated, by physical, electronic or any other
means, nor used as the basis for the manufacture or sale of OLDHAM equipment or for any other reasons without
prior consent from OLDHAM
W
WA AR RN NI IN NG GS S
* This document is not contractually binding. In the interests of its customers, OLDHAM reserves to modify the
technical specifications of its equipment without notice, in order to improve its performance.
* READ THIS MANUAL CAREFULLY BEFORE FIRST USE OF THE EQUIPMENT: this manual must be
read by any person who is or will be responsible for using, maintaining or repairing this equipment.
* This equipment will only provide the announced performance levels if it is used, maintained and repaired
according to OLDHAM directives, by OLDHAM personnel or by personnel approved by OLDHAM
G
GU UA AR RA AN NT TE EE E
2 years guarantee in normal conditions of use on parts and technical labour, return in our workshops, excluding
consumables (sensors, filters, etc.)

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CONTENTS
1. DESCRIPTION..............................................................................................7
1.1. General.............................................................................................................................7
1.2. Rack..................................................................................................................................8
1.3. The various printed circuit boards...................................................................................8
2. INSTALLATION AND CONNECTIONS..................................................9
.1. Installation: recommendations ............................................................................................9
.2. Electrical connections of the MX52 Unit (Fig. 8)................................................................9
2.2.1. Alternative power supply.........................................................................................9
2.2.2. DC power supply ...................................................................................................10
.3. Detectors (Figures 9 and 12).............................................................................................10
2.3.1. Explosimetric detectors of PONT type..................................................................10
2.3.2. 3-wire detectors 4-20 mA: 3 connecting wires for shielded cable.........................11
2.3.3. 2-wire detectors 4-20 mA: 2 connecting wires for shielded cable.........................11
2.3.4. FIRE detectors: 2 connecting wires for shielded cable..........................................11
2.3.5. FLAME detectors: 2, 3 or 4 connecting wires for shielded cable depending on
utilization ...............................................................................................................................11
2.3.6. CO2 detector of type “Ventostat VT”....................................................................13
2.3.7. Specific case of intrinsic safety detectors..............................................................13
2.3.8. Other detectors with standardized current output..................................................14
2.3.9. Parking application ................................................................................................14
.4. Connecting the unit to external devices.............................................................................15
2.4.1. Slaving controls......................................................................................................15
2.4.2. 4-20 mA current outputs (Fig. 12).........................................................................16
2.4.3. RS 232 and RS 485 outputs ...................................................................................16
2.4.4. Remote acknowledgement.....................................................................................18
3. STARTING UP............................................................................................19
3.1. Checking the installation ...............................................................................................19
3.2. Switching on the unit......................................................................................................19
3.3. Operating modes............................................................................................................20
3.3.1. Audio warning device (buzzer)..............................................................................20
3.3.2. Light-emitting diodes (LED) (Fig. 26) ..................................................................20
3.3.3. Alarm thresholds....................................................................................................20
3.3.4. Fault thresholds......................................................................................................25
3.3.5. Measuring unit .......................................................................................................26

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4. UTILIZATION............................................................................................27
4.1. List and functions of the various items of “USER” equipment for programming and
calibration of the unit.................................................................................................................27
4.1.1. Keypad (see Figures 26 and 4)...............................................................................27
4.1.2. Maintenance keys...................................................................................................28
4.1.3. Potentiometers........................................................................................................28
4.2. Menus.............................................................................................................................29
4.2.1. The various menus and their functions..................................................................29
4.2.2. Block diagram of the scrolling of the various menus ............................................29
4.2.3. Detailed flow diagrams of each menu....................................................................31
5. SETTING THE MX52 UNIT INTO SERVICE.......................................45
5.1. Programming the unit....................................................................................................45
5.2. Programming the measuring channels..........................................................................45
5.2.1. Programming..........................................................................................................45
5.2.2. Copy.......................................................................................................................46
5.3. Calibrations ...................................................................................................................46
5.4. 4-20 mA output adjustment for a measurement channel................................................50
6. MAINTENANCE.........................................................................................51
6.1. Periodic / preventive maintenance.................................................................................51
6.1.1. On the MX52 unit..................................................................................................51
6.1.2. On the detectors .....................................................................................................51
6.2. Failures: causes and remedies.......................................................................................52
6.3. Scrapping of MX52 ........................................................................................................55
6.4. List of spare and replacement parts...............................................................................55
7. VIEWS SPECIFIED IN THE MANUAL .................................................57
8. DETAILED TECHNICAL CHARACTERISTICS.................................87
9. Special Specifications for use in Potentially Explosive Atmospheres in
accordance with European Directive ATEX 94/9/EC........................................89

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1
1. . D DE ES SC CR RI IP PT TI IO ON N
1.1. General
The MX52 measuring and alarm unit can be fitted with between one and 16 independent channels.
Each channel is connected to one or more detectors installed in the locations to be monitored.
The measurement that is output from the detector is displayed on the MX52 unit and compared with
alarm thresholds. If thresholds are exceeded, the unit actuates relays which can be used to control
external devices.
REMARK
The equipment of the MX52 unit comprises line PCBs, each equipped with two channels. However,
each channel is independent and can be connected to any type of OLDHAM detector provided that
the PCB is suitably programmed. The number of line PCBs is always equal to the mixed even
number greater than the number of channels used divided by two.
M
MA AI IN N C CH HA AR RA AC CT TE ER RI IS ST TI IC CS S
Rack 3U 19”
AC or DC power supply
16 measuring inputs for detectors
Display of measurement on a plasma display panel (2 lines - 16 characters)
One keypad with four keys for the user
One “CALIBRATION” key and one “PROGRAMMING” key for maintenance
(accessible only by opening the front panel)
3gas alarms per channel
-Two instantaneous rising or falling thresholds, manual or automatic clearing, with
“extractor control logic (tunnel parking application)”
-One rising or falling threshold, automatic clearing, triggering by time delay or
average
Relaying
Total of 34 relays distributed as follows:
-Two relays per channel, with positive or negative safety, contacts open or closed
at rest for the first two thresholds

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-One relay common to channels for third thresholds or for all alarms (buzzer
transmission), with positive or negative safety, contacts opened or closed at rest
-One relay common to channels for faults and failures, constant positive safety
mode, contacts open or closed at rest.
Current output (4-20 mA) per measuring channel.
Common audio alarm that can be acknowledged in the case of occurrence of gas alarms.
1.2. Rack
The MX52 rack is of the 3U 19” type.
Overall dimensions: Fig. 1
Overall view, front profile: Fig. 2
Overall view, back profile: Fig. 3
1.3. The various printed circuit boards
Overall view: Fig. 4
Power board and module: Fig. 5
MICRO board: Fig. 6
Measuring channel board: Fig. 7
Front connection board: Fig. 4

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2
2. . I IN NS ST TA AL LL LA AT TI IO ON N A AN ND D C CO ON NN NE EC CT TI IO ON NS S
Please ensure you read the paragraph: Special Specifications for use in Potentially Explosive
Atmospheres in Accordance with European Directive ATEX 94/9/EC
.1. Installation: recommendations
The MX52 unit can be installed in any premises without an explosive atmosphere. They should
preferably be placed in a ventilated and monitored location (guardhouse, control room,
instrumentation room, etc.).
Attachment is to be ensured in accordance with the dimensions in Figure 1 (four attachment points).
REMARK
In order to permit the swivelling front panel of the unit to be opened completely, allowance must be
made for opening by rotation through 180° downwards.
Before making any connections, the unit should be switched off using the main On/Off switch
below and to the left of the FRONT circuit (see Figures 4 and 26).
.2. Electrical connections of the MX52 Unit (Fig. 8)
The MX52 unit is equipped with a pulse automatic device which enables to connect 24 V DC
voltage in a lack of 220 V AC voltage so we can use no expansive save power supply.
2.2.1. Alternative power supply
-Voltage: 230 V AC (207 to 244 V) 50/60 Hz
-Maximum power: 300 VA
-Maximum current in cable: 1.5 A
-Cable: 3 x 1.5 mm² (including earth)
-Location of connection terminal blocks: Fig. 8, item A
-Protection: the phase and neutral wires are protected by time-delayed 2 A
fuses located at the rear of the power module.
-Voltage: 103 to 122 V AC - 50/60 Hz on option
CAUTION
It is mandatory that the appliance must be earthed. A terminal is reserved for this purpose at the
back of the power module: see Fig. 5. This connection is required in order to ensure correct
operation of the following:
-mains power interference filter,
-protective devices against electromagnetic interference.

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2.2.2. DC power supply
-Voltage: 21 to 30 V continue. The "-" from continue power supply is linked to
earth (and earth being linked to frame).
-Maximum power: 240 W
-Maximum current in cable: 12.5 A
-Cable: 2 x 2.5 mm² or 2 x 4 mm² depending on length
-Location of terminal block: see Fig. 8, item D
-Protection: by two fuses located at the back of the power module (Fig. 8, item E)
.3. Detectors (Figures 9 and 12)
REMARK
-The detectors are linked by SHIELDED cables.
-The utilization of shielded cables is MANDATORY
-The earth braid of shielded cables must be connected to the earth at one end
only.
CAUTION
Each channel is configured in the factory for a given type of detector (explosive gas, toxic
gas, fire or flame). If two different types of detector are interchanged, this may result in
the destruction of the central unit or of the detector.
2.3.1. Explosimetric detectors of PONT type
Three connecting wires for a shielded cable.
Resistance of detector / unit cable: 16 ohms maximum per wire, i.e. 32 ohms in loop (1 km for cable
3 x 1.5 mm²).
Connection on MX52 unit: see Fig. 10

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2.3.2. 3-wire detectors 4-20 mA: 3 connecting wires for shielded cable
-Resistance of detector / unit cable: 16 ohms maximum per wire, i.e. 32 ohms in loop
(1 km for cable 3 x 1.5 mm²).
-Connection on MX52 unit: see Fig. 10.
2.3.3. 2-wire detectors 4-20 mA: 2 connecting wires for shielded cable
-Resistance of detector / unit cable: 32 ohms maximum per wire, i.e. 64 ohms in loop
(2 km for cable 2 x 1.5 mm²).
-Connection on MX52 unit: see Fig. 11.
2.3.4. FIRE detectors: 2 connecting wires for shielded cable
The current commercial designations are as follows:
-“Thermovelo” detectors of type EC 11 (sensitive to temperature variations)
-Ionic detectors of type EI 1 100 (sensitive to smoke)
-Optical detectors of type EO 1 100 (sensitive to smoke)
-Resistance of detector / unit cable: 28 ohms maximum per wire, i.e. 56 ohms in loop (2 km for
cable 2 x 1.5 mm²)
-Fire detectors can be detected in parallel to a maximum of five. The end-of-loop resistor
(2.7 K) is to be placed at the end of the line on the last detector.
-Connection on MX52 unit: see Fig. 11.
2.3.5. FLAME detectors: 2, 3 or 4 connecting wires for shielded cable
depending on utilization
REMARK
The detectors can be supplied with power either via the MX52 unit or by an auxiliary 24 V DC
source.

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These detectors can operate in standalone mode:
24 V DC power supply and direct utilization of relay contacts in accordance with the technical
specification corresponding to the detector used.
The current commercial designations are as follows:
-model 20/20 U - analog - type UV - 752002 (sensitive to UV radiation)
-model 20/20 UC - analog - type UV (sensitive to UV radiation)
-model 20/20 UB - µP technology - type UV - 772002 (sensitive to UV radiation)
-model 20/20 UBC - µP technology - type UV (sensitive to UV radiation)
-model 20/20 LC - analog - type UV/IR (pyroelectric, combination of UV and IR
detectors)
-model 20/20 LBC - µP technology - type UV/IR (pyroelectric, combination of UV and
IR detectors)
-model 20/20 I - µP technology - triple IR detector - 780002 (pyroelectric, sensitive to IR
radiation)
These detectors are equipped with various types of terminal block (see table below).
Model
20/20 U
20/20 UC
20/20 UB
20/20 LC
20/20 UNC
20/20 LBC
20/20 I
Type
of terminal
block
B
C
A
C
C
C
A
-Resistance of cable / unit
-In the case of local 24 V DC power supply:
8.5 ohms maximum per wire, i.e. 17 ohms in loop
-In the case of power supply via the MX52 unit:
3 ohms maximum per wire, i.e. 6 ohms * in loop
4 ohms for detector 20/20 I (IR3)
-Connection on MX52 unit (ONE detector per measuring channel ONLY):
-detector equipped with a terminal block of type A: see Fig. 13
-detector equipped with a terminal block of type B: see Fig. 14
-detector equipped with a terminal block of type C: see Fig. 15
Example of the utilization of the 4-20 mA signal from flame detectors equipped with connectors of
type A or C: see Fig. 16.
Example of the utilization of detectors equipped with connectors of either type A or type B and with
auxiliary power supply. The auxiliary power supply must be able to supply power to the number of
detectors planned in the measuring loop (see Fig. 17).

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REMARK
In the case of this application, the maximum of five flame detectors can be connected in the
measuring loop.
Example of the utilization of IR3 or UV/IR detectors equipped with connectors of type A with a
local junction box and galvanic insulation (see Fig. 18).
2.3.6. CO2 detector of type “Ventostat VT”
-Connection on MX52 unit: see Fig. 20.
-Resistance of detector/unit power cable: 12 ohms maximum per wire, i.e. 24 ohms in
loop.
-4-20 mA output: maximum load = 280 ohms (whole loop)
2.3.7. Specific case of intrinsic safety detectors
Two types of intrinsic safety barrier can be used: Z787 / EX and MTL787S+.
PRECAUTIONS
Before connecting the barrier to the unit, check that the voltage is < 25 V DC.
-A short circuit in the electrical connections will result in destruction of the barrier.
-Perform wiring in the DE-ENERGIZED state.
-The electrical link between the MX52 unit and the clipper is made using a screened
cable with two active conductors with a maximum resistance of 12 ohms each.
REMARK
In classified areas, the installation must comply with the standards in force.
-Connections on MX52 unit: see Fig. 21.
IMPORTANT
All intrinsic safety installations must be APPROVED as a whole assembly by an approved
organization (DRIRE, etc.).

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OLDHAM “INTRINSIC SAFETY” BARRIERS
Type of IS
barrier
Reference
Specific features
OLDHAM box
reference
Z787 / EX
6184703
To be fitted on DIN
RAIL
MTL787S+
6797100
To be fitted in an
approved box:
MANDATORY
For 2 clippers
6797192
For 5 clippers
6797547
For 12 clippers
6797101
2.3.8. Other detectors with standardized current output
Any detector (with 2 wires or 3 wires) that can be supplied with power between 19 V DC and 32 V
DC and that supplies a standardized current (signal) of between 4 and 20 mA can be connected to
the MX52 unit.
The connection requirements are identical to those for the corresponding OLDHAM detectors (see
Fig. 22).
2.3.9. Parking application
CTX300 "Co parking" toxic gas detectors can be fitted in parallel when a mean gas concentration is
to be obtained. The detectors must, imperatively, be located in the same area. In this case, a
maximum of five detectors can be connected (see Fig. 23).

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.4. Connecting the unit to external devices
2.4.1. Slaving controls
The 16 measuring channels of the MX52 unit are each equipped with two relays which can be used
to control external devices: sirens, solenoid valves, extractors, telephone calls, etc..
For each measuring channel, the relays are distributed in the following manner (see Fig. 7):
-a relay associated with the triggering of alarm 1,
-a relay associated with the triggering of alarm 2,
-use of open or closed contacts selected with a jumper (see Fig. 7),
-use of positive or negative safety selected by programming (see the CHANNEL
programming menu),
-contact outputs on the back of the measuring board (see Fig. 12).
-An example of connection is given in Fig. 24:
-a siren connected to relay AL1 will be actuated as soon as alarm 1 is triggered,
-a solenoid valve connected to relay AL2 will be actuated as soon as alarm 2 is
triggered.
For all channels:
-A common relay associated with the triggering of alarm 3 for the 16 channels.
By programming, this common relay can also be used for the remote transmission of the
audio warning signal. (This relay will then be associated with all the unit’s alarms). The
3 contacts are available back to power supply module (fig 8).
-A fault relay associated with the triggering of channel faults (detector failures, electrical
connections, excessively negative zero, etc.). This relay will always be in positive safety
mode (see Fig. 5). The use of open or closed contacts is selected by programming on
common board.
-Common relay contact outputs on the back of the power module: Fig. 8.
REMARK
Owing to the breaking capacity of the MX52 unit’s relays which is limited to 2 A / 250 V AC or 30
V DC, external intermediate relays must be used if the devices to be controlled require high power
levels.

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2.4.2. 4-20 mA current outputs (Fig. 12)
For each measuring channel, the MX52 unit is equipped with a 4-20 mA output that can be used to
retransmit measurements to a recorder or an external PLC. The maximum resistance in loop mode is
600 ohms. The earth connections for the 4-20 mA outputs are common and the unit. The 4-20 mA
lines are not galvanically insulated one from the other. The current output varies according to the
measurement and has several states, as follows:
-On starting up the unit: I < 1 mA
-With FAULT: I < 1 mA
-In MAINTENANCE mode: I = 2 mA
-ZERO MEASUREMENT: I = 4 mA
-Full scale: I = 20 mA
-Out of range or “in doubt”: I > 23.2 mA
An example of the connection of a multi-channel recorder is given in Fig. 25.
2.4.3. RS 232 and RS 485 outputs
RS232 OUTPUT
A computer can be connected on a female sub.D/DB9 type connector located on the back of the
micro board (fig6 repA). The MX52 programming, from outside, will be possible thanks to this
connection.
RS 232 OUTPUT USING
-Remove the DB9 connector (pmug with an internal strap)
-Connect a link cable ref.6315831 which will link the monitor to the computer on the
MX52 available female connector DB9 (repA Fig6)
MX52
ORDINATEUR PC
Cordon liaison PC/MX52
(1)
(2)
-when the using is stopped : no connect the cable and put the male DB9 "plug" again.
Female DB9
Male DB9
MX52
PC COMPUTER

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RS 485 OUTPUT (PINABLE ON FIG 29)
Several MX52 units can be linked to a single computer, which is the "master" of the network. In
this case, a "SLAVE NUMBER" (by programming/unit) is asigned to each MX52 unit.
This RS 485 output can be galvanically insulated as an option.
1st case : no galvanic insulation
-no mounted insulation component
-2 polarization electrical resistances are programmed and welded
2nd case : with galvanic insulation
-mounted and welded insulation component
-no programmed polarization electrical resistance for "plu" (+ 5V)
a) with RS 485 shielded
-no programmed polarization resistor for "moins" (GND)
b) without RS485 shielded
-programmed polarization resistor for "moins" (GND)
End loop resistor
It is located on the MX52 micro board and must be programmed with the last MX52 unit of the
loop (by pins) with a 120 Ohms value.
The MX stored data are some instantaneous values
The RS485 output is a half duplex type.
RS 485 OUTPUT USING
-No change the sub D/DB9 "plug" connector
-Connect the screwed connector terminals 3,4 and 5, located on the back of the MX52
unit (repB Fig6). See connection details fig 29.
-Owing to mounted wires or not (following the mounting and the equipment linked or not
on the earth…).

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IMPORTANT
All details regarding the RS 485 complete description (Modbus / Jbus format, structures,
adresses aso…) are developped in a leaflet ref. D 813 577.
CAUTION
A computer must be used in order to printout the data stored by the MX52 unit.
Several MX52 units can be connected to a single computer which is the "MASTER". In this
case, a SLAVE number is assigned to each MX52 unit.
2.4.4. Remote acknowledgement
It is possible to allow remote acknowledgement by connecting on connector 5 plugs, on the back or
the micro board : see fig 6 item B.

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3
3. . S ST TA AR RT TI IN NG G U UP P
3.1. Checking the installation
It is checked that, at least, all connections have been made and that the complete installation
complies with current standards in force.
CAUTION
OLDHAM is not responsible for the compliance of the complete electrical safety system.
The MX52 unit is switched on by means of circuit breakers * provided for that purpose and which
ensure protection of the mains power unit.
* The circuit breakers are to be selected according to the power consumption levels specified by the
manufacturer and the length of the electric cables.
3.2. Switching on the unit
CAUTION
The handling operations and adjustments described in these paragraphs are strictly
reserved for authorized personnel as they are liable to affect detection safety.
To start up the MX52 unit, you must:
-swivel the front panel,
-press the ON/OFF button located to the bottom left-hand side of the FRONT
circuit: see Figures 4 and 26 (item A).
-The display panel then shows, for example:
MX 52 V2.0
The unit then goes into INITIALIZATION mode for one minute. Consequently, all the alarms are
inhibited and the current outputs are 1 mA for the channels in service. The unit then performs a self-
test * on its buzzer and all its night-emitting diodes. At the end of this one-minute period, the
channels in service return to normal operation and the corresponding alarms and relays are enabled.
* The user can carry out a “manual-self test” by pressing the test key at any time (see Fig. 26).
This self-test lasts 20 seconds and the display panel may show the following displays one after the
other, for example:

20
then
The user can interrupt the self-test cycle before it is completed by pressing the
ACKNOWLEDGEMENT key.
3.3. Operating modes
3.3.1. Audio warning device (buzzer)
In normal operation, the audio warning device is triggered whenever a fault or an alarm appears.
The audio warning device can be stopped by pressing the ACKNOWLEDGEMENT key or by
remote acknowledgement. The buzzer makes a continuous or discontinuous sound (according to the
programming of the unit) if an alarm threshold is exceeded.
3.3.2. Light-emitting diodes (LED) (Fig. 26)
Each channel is equipped with five LEDs (visible and identified on the FRONT panel).
LED
Extinguished
Illuminated
in steady mode
Flashing
GREEN
Channel not in
service
Channel in service
Threshold AL1 exceeded
(manual clearing) and not
acknowledged
1st red
AL1 not triggered
Threshold AL1 exceeded
(automatic clearing)
Threshold AL2 exceeded
(manual clearing) and not
acknowledged
2nd red
AL2 not triggered
Threshold AL2 exceeded
(automatic clearing)
3rd red
AL3 not triggered
Threshold AL3 exceeded by mean
or time (automatic clearing)
Yellow
No fault
Fault on channel
-Channel being calibrated or
programmed
- Detector being calibrated
3.3.3. Alarm thresholds
Each of the three alarm thresholds can be programmed independently for each channel. (See the
“Channel programming” menu).
MX 52 v2.
xx LEL CH4
*** SELF-TEST ***
xx LEL CH4
Line corresponding to
the channel displayed
when the ENTER key
was pressed