Allen-Bradley micrologix 1500, User Manual

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Publication 1764-UM001A-US-P
3-4 Wiring Your Controller
If the outputs are dc, we recommend that you use an 1N4004 diode for surge
suppression, as shown below.
Suitable surge suppression methods for inductive ac load devices include a varistor,
an RC network, or an Allen-Bradley surge suppressor, all shown below. These
components must be appropriately rated to suppress the switching transient
characteristic of the particular inductive device. See the table on page 3-5 for
recommended suppressors.
If you connect an expansion I/O 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 3-5
for recommended suppressors.
VAC/
Out 0
Out 1
Out 2
Out 3
Out 4
Out 5
Out 6
Out 7
COM
+24V dc
IN4004 Diode
Relay or Solid
State dc Outputs
24V dc common
Surge Suppression for Inductive ac Load Devices
Output Device
Output Device
Output Device
Varistor RC Network Surge
Suppressor