MSA Senscient ELDS 1000 series, Operating Manual

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Problem Solving
118
Senscient ELDS™
Rev 15
GB
7. Problem Solving
The majority of problems or faults can be diagnosed and corrected using the installation and
alignment kit available for Senscient ELDS™ systems. The installation and alignment kit includes:

Industrial computer running SITE

Alignment Telescope
An electrical multimeter is also useful when diagnosing electrical/wiring problems.
CAUTION
Senscient ELDS™ units do not contain any user replaceable parts. Do not open the main
enclosure of a Transmitter or Receiver unit. The warranty of units which have been opened may
be invalidated.
7.1. The Commonest Problems, Issues or Misconceptions Affecting Successful Use of ELDS
OPGDs
Extensive in-service operational experience with ELDS OPGDs has enabled Senscient to identify
the commonest problems, issues or misconceptions that affect the success with which users
employ these gas detectors. This short section explains these problems, issues or
misconceptions; and is intended to help users to avoid experiencing them. These problems, issues
and misconceptions are presented in order of descending probability / frequency of occurrence:

Insufficient Voltage Reaching the ELDS Units When Powered Up
In common with other infrared open path gas detectors, ELDS 1000 & 2000 Series OPGDs
require a stable, sufficient and reliable supply of +24V power in order to operate reliably.
Correctly engineered PSU and cabling arrangements will contribute greatly to the reliability and
availability of an ELDS OPGD based gas detection system. Carefully review the power supply
and cabling arrangements to be used to power ELDS units before the cables or power supplies
are specified, purchased and installed. (See section 3.3.5 for detailed information upon ELDS
power requirements and cabling.)

The ELDS OPGD is Generating False Gas Alarms
The combination of an open path gas detection configuration and the capability to detect target
gas(es) at low ppm.m levels enables ELDS OPGDs to detect leaks of toxic or flammable
gas(es) that are undetected by point gas detectors. This can give rise to the misconception that
the gas readings being signalled by an ELDS OPGD are false; when in fact they are genuine
but only being detected by the ELDS OPGD. To date there has only been a single proven
instance of a false gas alarm being raised by an ELDS OPGD, the cause of which was
identified and eliminated in 2010. In every other instance where false gas alarms were
suspected and a proper investigation was conducted, genuine sources or causes for the gas
readings that were signalled were eventually identified. In this way, many potentially dangerous
gas leak sources and mechanisms were eliminated, making plants and facilities safer than they
were previously.