Light Load Operation And Standby Generating Sets - Perkins 4006 User Handbook Manual

LIGHT LOAD OPERATION & STANDBY GENERATING SETS
If an engine is operated on a load less than
25-30% of its rated outout, certain symptoms
will be observed which may give cause for
concern.
The usual results of this operation are
heavier than normal
consumption, and oil leaks from the air and
exhaust manifolds.
particularly evident on standby generator set
applications, where a weekly exercise on no
load is common practice.
These phenomena are due to the fact that:
1. Turbocharger oil seals are not fully
effective on light load, which results in oil
being delivered together with the air into
the engine air manifolds.
2. The cylinder temperatures are too low to
ensure complete burning of all the fuel
delivered.
This results in an unsightly drip from the
exhaust manifold junction glands.
A further result is that of abnormal carbon
build-up on the valves, piston crowns and
exhaust ports. Thus the normal service
interval of see Maintenance Schedules
between top overhauls may be reduced.
Fuel dilution of the lubricating oil will also
occur.
It is therefore recommended that the
following precaution are observed:
1) Running on light load should be avoided
or reduced to the minimum period. If
weekly exercising on no load is carried
out, the running period should be kept
down to say, 10 minutes, or until the
battery charging rate returns to normal
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lubricating oil
This condition is
2) Every year the engine or generator set
should be run on full load for four hours,
to burn off accumulations of carbon in the
engine and exhaust system. This may
require the use of a 'dummy load'. The
load should be built up gradually from
zero over the four hour run.
On standby sets, air cleaner elements
should be changed annually. Oil and fuel
filter elements should be changed every
six months. The fuel injectors should be
checked every 2 years.
There is absolutely no danger of failure or
breakdown resulting from light load operation,
providing the above recommendations are
followed, in addition to the normal procedures
laid down in this manual.
4006/8 Diesel, May 1998