Honeywell HC900, Руководство пользователя и инструкция по установке

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Revision 6 HC900 Process & Safety Controller User and Installation Manual 59
21 April 2017
CE Conformity
Electrical noise produces undesirable effects in measurements and control circuits.
Digital equipment is especially sensitive to the effects of electrical noise. You should use the following
methods to reduce these effects:

Supplementary bonding of the controller enclosure to a local ground, using a No. 12 (4 mm 2 ) copper
conductor, is recommended. This may help minimize electrical noise and transients that may adversely
affect the system.

Separate external wiring – group connecting wires into bundles (see Table 5) and route the individual
bundles through separate conduits or metal trays.

Use shielded twisted pair cables for all Analog I/O, Process Variable, RTD, Thermocouple, dc millivolt,
low level signal, 4-20 mA, Digital I/O, and computer interface circuits. Ground shields as described in
the section I/O Module Installation and Wiring page 77.

Use suppression devices for additional noise protection. You may want to add suppression devices at the
external source. Appropriate suppression devices are commercially available.

Refer to document 51-52-05-01 How to Apply Digital Instrumentation in Severe Electrical Noise
Environments for additional installation guidance .
Grouping Wires for Routing
Wires that carry relatively high electrical energy can produce unwanted noise in wires that transmit signals
of relatively low energy, particularly when they are placed parallel in long wiring runs. Collect and bundle
wires of similar type, and route the bundle separate from bundles of other types. Table 6 provides
suggested guidelines for grouping wires.
Table 5
– Guidelines for Grouping Wires
Wire Group Wire Functions
High voltage
(>50 Vdc/Vac)

AC Line power wiring

Earth ground wiring

Control relay output wiring

Line voltage alarm wiring
Signal
(<15 Vdc)
Analog signal wire, such as:

Input signal wire (thermocouple, 4 mA to 20 mA, etc.)

4-20 mA output signal wiring

Slidewire feedback circuit wiring
Communications
Low voltage
(<50 Vdc/Vac)

Low voltage alarm relay output wiring

Low voltage wiring to solid state type control circuits