Xylem DIQ/S 281, Operating Manual

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Installation DIQ/S 281
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(according to the technical data of the instrument input or output)
– Overvoltage limitations of overvoltage category II
 Suitable external separator (e.g. switch or circuit-breaker) for the power sup-
ply of permanently installed instruments with separate power connection
– compliant with the following regulations
- IEC 60947-1
- IEC 60947-3
– in the vicinity of the instruments (recommendation)
 Flame resistant (cable and lines),
compliant with the following regulations
– UL 2556 VW-1 (for USA, Canada)
– IEC 60332-1-2 (outside the USA, Canada)
3.4 Installation guidelines for lightning protection
During the use of the DIQ/S 281 universal transmitter, particularly in outdoor
areas, adequate protection against (electrical) surges must be provided. A surge
is a summation phenomenon of surge voltage and surge current. It is generated
through the indirect effect of a lightning event or switching operation in the
mains, in the grounding system and in information technology lines.
To be adequately protected against the damaging effects of surges, an inte-
grated concept of the following protective measures is required:
 internal device-related protective measures and
 external protective measures of the installation environment.
The internal device-related protective measures are already integrated in the
YSI online instrumentation as so-called 'lightning protection' (see
chapter 9 T
ECHNICAL DATA
).
The external protective measures of the installation environment can be carried
out with respect to the following guidelines:
1 All lines of systems must be
a) installed inside (or else close to) the grounded metallic mounting construc-
tions, e.g. handrails, pipes and posts if possible
b) or, particularly in the case of longer lines, laid in the ground.
Background: The formation of highly lightning hazardous inductive loops be-
tween the cables and ground is avoided through the low clearance of the
grounded metal construction or by installation in the ground.
2 Only IQ cable material may be used. This cable material is an important pre-
requisite for the hazard-free discharging of the surge without inadmissibly
high overvoltages developing along the line at the same time that could have
a damaging effect on the individual components.
3 All metallic mounting constructions (handrails, pipes, posts etc.) on which