Page 6 - August 2022 Track N Times

TECHNICAL TRAINING

What Is Reverse Power?

By: Brian Giop, Manager International Services

Reverse power is the phenome-
non of the Generator becoming a
motor. This can be explained as
the voltage of the generator drops
below the buss voltage and takes
power from the buss to maintain
its synchronization. To put this in
a simple analogy imagine contain-
ers of water, one being your buss
power and the others (2 or more)
being your generators output,
connected by a tube. If the water
(your voltage) remains equal to
the buss there is an equilibrium. If
one of the generator containers
drops its level the flow can come
into the generator container to
raise it to be equal of the other
containers. In essence this turns
your Generator into a motor
which then drives your engine
instead of the engine driving your
generator.

Common causes of reverse power on our equipment:
1. Prime Mover (engine) Fault

Almost always a fuel issue. The engine can no longer provide the power needed to keep the generator
output at the level of the buss power. This can be due to fuel filters/ bad fuel, ECM/ Governor issues, or
air filters. If the engine is unable to keep the approximate 1800 RPM the output from the generator will
not match the buss voltage and frequency.

2. Generator Excitation Loss
Excitation check advice provided by Specialist Technician
Ryan Steffan: When a generator goes into reverse power or
trips offline when loaded one of the most likely causes is
the generator excitation. Inspect the regulator for burning/
damage as shown in the image (right). If the rectifier diodes
fail it takes more field excitation to build voltage. Once the

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VOLUME 3 : ISSUE 7