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

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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.

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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. . 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. . 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