Engine - Hobart 6921 Series Operation And Maintenance Manual

OM-2040 / Operation and Maintenance Manual
90D20 / Generator Sets
e. Engine
The engine and its accessories require a major portion of the generator set lubrication and
maintenance. The following recommendations are taken from the engine manufacturer's operation
manual.
(1) Lubrication schedule
Time schedules indicated on the Lubrication Chart, Fig. 1, are approximate. They are based on
average operating conditions. It may be necessary to lubricate more frequently under severe
operating conditions such as: low engine temperatures, excessively heavy loads, and high oil
temperatures, or intermittent operation. However, time intervals should not exceed those
indicated in the chart without careful evaluation.
(2) Oil specification
Oil recommended by the engine manufacturer is identified by a military specification number,
MIL-L-2104B. Because of the substantial increase in additive concentration in some
MIL-L-2104B oils to meet service "MS" requirements, recommended oil is qualified still further by
the following limitations.
a. Zinc: between a minimum of 0.07 and a maximum of 0.10 percent by weight.
b. Sulfated ash: (ASTM D-874) of 1.00 percent maximum by weight, (except lubricants that
contain only barium detergent-dispersants where 1.50 percent by weight is allowed).
NOTE: Diesel lubricating oil specifications are discussed further in the Deutz Diesel, "Operator's Manual".
(3) Oil viscosity
The viscosity of the oil being greatly influenced by the ambient temperature, the choice of the
SAE grade should be governed by the ambient temperature at engine site. (See page 86 of
Deutz Operation Manual) . If temperatures temporarily fall below the limit of the SAE-grade
selected, this will merely affect the starting performance but cause no engine damage. Since too
viscous an oil causes starting difficulties, the choice of the viscosity grade during winter operation
should be governed by the ambient temperature prevailing at the time of starting the engine. Oil
changes as a function of ambient temperatures can be avoided by using multigrade oils.
(4) Change engine oil
The following oil change recommendations are taken from Duetz Diesel Operator's Manual.
Important: Should the engine run less than the hours stated in the following table, the oil must
be changed in any case once a year.
Engine Application
Tractors, lift trucks, cranes, construction
machinery, rail traction units, ships,
base-load generator sets, pumps, farm
equipment (seasonal) underground
mining, road sweepers, winter service,
emergency generator sets, emergency
pumps
February 28/94 Revised
Oil Change
Category of Intervals: Oil
oil stressing
Grade
API:CC/SE
250 Hours
A
125 Hours
B
Oil Change
Intervals: Oil
Grade
API:CD/SE
500 Hours
250 Hours
Chapter 2-1
Page 5