ircon Modline 4 Installation And Operation Manual Download

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Appendix

A–5

4.3

SPECIAL HANDLING OF ELECTROSTATIC

SENSITIVE DEVICES

Some devices may be damaged by electrostatic
charges. These devices are identified and should
be handled in the special manner specified by the
manufacturer.

NOTE: Plastic wrapping materials used to ship
these devices may be conductive and should not
be used as insulating material.

4.4

COMPATIBILITY OF DEVICES WITH

APPLIED VOLTAGES AND FREQUENCIES

Prior to energization, users and installers should
verify that the applied voltage and frequency agree
with the rated voltage and frequency specified by
the manufacturer.

NOTE: Incorrect voltage or frequency may cause a
malfunction of, or damage to, the control.

4.5

TESTING PRECAUTIONS

When testing solid state control, the procedures
and recommendations set forth by the manufactur-
er should be followed.

When applicable, instrumentation and test equip-
ment should be electrically equivalent to that rec-
ommended by the manufacturer for the test proce-
dure. A low impedance voltage tester should not
be used.

High voltage insulation tests and dielectric tests
should never be used to test solid state devices. If
high voltage insulation of field wiring is required,
solid state devices should be disconnected.
Ohmmeters should only be used when and as rec-
ommended by the equipment manufacturer.

Testing equipment should be grounded; if it is not,
special precautions should be taken.

4.6

STARTUP PROCEDURES

Checks and tests prior to startup and startup pro-
cedures recommended by the manufacturer
should be followed.

4.1.2

Electrical noise is a very important considera-

tion in any installation of solid state control. While
wiring practices may vary from situation to situa-
tion, the following are basic to minimizing electrical
noise:

Sufficient physical separation should be main-
tained between electrical noise sources and
sensitive equipment to assure that the noise
will not cause malfunctioning or unintended
actuation of the control.

Physical separation should be maintained
between sensitive signal wires and electrical
power and control conductors. This separation
can be accomplished by conduits, wiring trays,
or as otherwise recommended by the manu-
facturer.

Twisted-pair wiring should be used in critical
signal circuits and noise producing circuits to
minimize magnetic interference.

Shielded wire should be used to reduce the
magnitude of the noise coupled into the low
level signal circuit by electrostatic or magnetic
coupling.

Provisions of the 1984 National Electrical Code
with respect to grounding should be followed.
Additional grounding precautions may be
required to minimize electrical noise. These
precautions generally deal with ground loop
currents arising from multiple ground paths.
The manufacturer’s recommendations should
be followed.

4.2

ENCLOSURES (COOLING AND

VENTILATING)

Suitable enclosures and control of the maximum
operating temperature, both of which are environ-
mental variables, may be needed to prevent mal-
function of solid state control.

The manufacturer’s recommendations should be
followed for the selection of enclosures, ventilation,
air filtering (if required), and ambient temperature.
These recommendations may vary from installation
to installation, even within the same facility.