Oldham MX15, Installation And Operating Instructions Manual

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9
In the event that the central unit is used with other types of sensors supplying a measuring
current of 4/20 mA, they should comply with paragraph 1.5 of Appendix II of the Atex 94/9/CE
Directive and be compatible with their characteristics (see central unit transfer curve).
Note: the test vibrations in accordance with EN61779-4 paragraph 4.13 have not been performed
because they do not apply due to the operating conditions of the MX15 central unit.
3
3
.
.
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As previously explained, the user who want to connect detectors other than INDUSTRIAL
SCIENTIFIC, should ensure that they are compatible with the central unit so that the unit is
considered a safety device.
3.1. Transfer curves of central unit in configuration 0 at 100% LEL
The following curve provides a response to the central unit regarding the measured value
and fault processing, based on the value of the input current supplied by the detector. In the event
that the user connects a detector of a brand other than INDUSTRIAL SCIENTIFIC to the MX15
central unit, he/she should ensure that the transfer curve is compatible with the input characteristics
of the central unit, so that the information provided by the detector is accurately interpreted. In
addition, the central unit should supply a sufficient supply voltage taking into account the cable
drops.
Caution: When the measurement is >= to 100% LEL, the measuring unit memorizes this scale
overrun, the channel passes to alarm and fault mode. The resetting of this status is manual and is
the responsibility of the user who should comply with the safety instructions of his/her site. The
resetting is either validated through an ON/OFF of the central unit or through a maintenance
operation.
4
mA
20
mA
100 % LEL
Signal supplied by
the detector in mA
Display
in % LEL
Fault
Fault
1.6
mA
0 % LEL
-15 % LEL
SUP