Troubleshooting
Power Troubleshooting
Power Troubleshooting in industrial control systems — covering 5 topic areas in the CurryControls.com controls and automation knowledge hub.
Written guides in this section
Full references, procedures, and diagnostic guides published under Power Troubleshooting.
Loss of Control Voltage
Control voltage that drops out for a moment and comes back, resetting controllers and dropping contactors: utility sags when a large load starts, a transfer switch operation, a loose neutral, or an overloaded control transformer. Catching it with a recorder.
8 min readUpdated Sep 5, 2026
Power Supply Failure
A 24 volt DC supply whose output is gone, low, cycling, or noisy: an overload that has put it into current limit, a supply killed by heat and age, input voltage out of range, or surge damage. One test tells an overloaded supply from a dead one.
8 min readUpdated Sep 5, 2026
UPS Not Carrying Load
The power failed and the controls went down anyway: a battery aged out or never connected, a UPS sitting in bypass since a fault, an overload, loads on the wrong receptacles, or a failed self-test nobody read. Finding out which, and testing properly.
8 min readUpdated Sep 5, 2026
Voltage Sag on Motor Start
Lights dim, contactors drop, and controllers reset every time the big pump starts: the starting current of an across-the-line motor pulling down a weak source. Measuring the sag, checking the source, and fixing it with a soft starter or ride-through.
8 min readUpdated Sep 5, 2026
Generator Transfer Problems
The generator started and something still went wrong: no transfer, controls reset during the gap, drives faulted, pumps ran backward, or the retransfer caused a second outage. The sequence and its timers, neutral and rotation, and the monthly test.
9 min readUpdated Sep 5, 2026
Topics in this area
Loss Of Control Voltage
Loss Of Control Voltage — practical reference notes for controls engineers, integrators, and technicians working with power troubleshooting.
Power Supply Failure
Power Supply Failure — practical reference notes for controls engineers, integrators, and technicians working with power troubleshooting.
UPS Not Carrying Load
UPS Not Carrying Load — practical reference notes for controls engineers, integrators, and technicians working with power troubleshooting.
Voltage Sag On Motor Start
Voltage Sag On Motor Start — practical reference notes for controls engineers, integrators, and technicians working with power troubleshooting.
Generator Transfer Problems
Generator Transfer Problems — practical reference notes for controls engineers, integrators, and technicians working with power troubleshooting.
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