Allen-Bradley 20Y, Руководство по обслуживанию оборудования

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Rockwell Automation Publication 20Y-TG001C-EN-P - April 2017 29
Component Test Procedures Chapter 3
Inspect the Power Structure
To inspect the power structure, follow these steps.
1. Remove the protective barriers.
See Remove AFE Protective Barriers on page 44 .
2. Remove the protective front cover and terminal cover from the power
structure.
See
Remove Protective Covers from the Power Structure on page 46 .
3. Check components for burn marks, breakage, or foil delamination on
circuit boards.
Check all boards on the power structure.
4. Replace any of these components if they show evidence of burn marks,
breakage, or foil delamination.
Perform Forward and
Reverse Biased Diode Tests
for Power Structure
A forward biased diode test checks the semiconductor junctions between the
terminals and measures the voltage drop across those junctions. To pass each
test, the meter must display a voltage near 0.5V. If the test finds a short, the
meter displays ‘.000’. If the test finds an open circuit or reversed polarity, the
meter displays ‘.0L’ (zero load).
A reverse biased diode test finds an open circuit, and the meter displays ‘.0L’
(zero load)
.
To perform forward and reverse biased diode tests for the power structure,
follow these steps.
1. Remove power from the AFE.
See Remove Power from the AFE on page 37 .
IMPORTANT
The actual voltage readings can vary depending upon your equipment. If
your readings are not near the indicated values in the following tables,
verify that the actual voltage that is measured is consistent for the power
module.
~.0L
+
-
~0.5V
+
-
Forward biased test on
PN-junction
Reverse biased test on
PN-junction