Allen-Bradley Rockwell MicroLogix 1000 Instrucciones Para La Instalación página 13

Suitable surge suppression methods for inductive load devices include a varistor,
an RC network, or, for dc loads, a diode. These components must be appropriately
rated to suppress the switching transient characteristic of the particular inductive
device. See the table on page 12 for recommended suppressors.
As the following diagram illustrates, these surge suppression circuits connect
directly across the load device. This reduces arcing and damage of the output
contacts. (High transients can cause arcing that occurs when switching off an
inductive device.)
Surge Suppression for Inductive ac and dc Load Devices
Output Device
Output Device Output Device
Varistor
RC Network
If you connect a micro controller triac output to control an inductive load, we
recommend that you use varistors to suppress noise. Choose a varistor that is
appropriate for the application. The suppressors we recommend for triac outputs
when switching 120V ac inductive loads are a Harris MOV, part number V175
LA10A, or an Allen-Bradley MOV, catalog number 599-K04 or 599-KA04.
Consult the varistor manufacturer's data sheet when selecting a varistor for your
application.
For inductive dc load devices, a diode is suitable. A 1N4004 diode is acceptable
for most applications. A surge suppressor can also be used. See the table on
page 12 for recommended suppressors.
Installation Instructions
MicroLogix 1000 Programmable
Controllers
+
—
Output Device Output Device
Diode
(A surge suppressor can also be used.)
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