Introduction; Unit Identification; Model Numbers; Serial Numbers - Northern Lights M844W3 Operator's Manual

Servicing of marine engines and generator sets presents
unique problems. In many cases boats cannot be moved
to a repair facility. Marine engines cannot be compared
to the servicing of automobiles, trucks or even farm
equipment. Failures often occur in remote areas far
from competent assistance. Marine engines are taxed
far more severely than auto or truck engines; therefore,
maintenance schedules must be adhered to more
strictly.
MODELS INCLUDED
This manual covers the operating instructions for:
M844W3 marine generator sets,
M844DW3 marine generator sets,
Model numbers give the unit's application, block model, aspiration, and RPM:
M
M - Northern Lights marine
generator set
=
M844W3 Northern Lights marine diesel generator set with
an 844 engine and a PX-316K2 generator end.
US EPA TIer III.
M844DW3
= Northern Lights marine diesel generator set with an
844L engine and a PX-320K2 generator end. US EPA
TIer III.
M844LW3 = Northern Lights marine diesel generator set with
an 844L engine and a PX-320K2 generator end.
US EPA TIer III.
Generator set serial number plate.
Updated 10-13-20

Introduction

Unit Identification

Model Numbers

844
Model number of engine block
+
Bore Cylinders
84 mm 4

Serial Numbers

Your set has three serial numbers:
on the block,
Use the serial number on the generator set plate when ordering parts
or in correspondence. The generator set plate is found on the service
side of the generator and resembles the drawing at left.
OM844W3 5/21
2
Failures can begin with minor problems that are
overlooked and become amplified when not corrected
during routine maintenance.
As operator, it is your obligation to learn about your
equipment and its proper maintenance. This is not a
comprehensive technical service manual. Nor will it
make the reader into an expert mechanic. Its aim is to
aid you in maintaining your unit properly.
M844LW3 marine generator sets,
M844LW3G marine generator sets, and
M20CRW3 commercial generator sets.
D, L, W, G, C, 3
D - Series designation
+
L - Long stroke engine
W - Auxiliary Winding in Generator
End
G - GEM series base frame
3 - US EPA Tier III compliant
M844LW3G = Northern Lights marine diesel generator set with
an 844L engine and a PX-320K2 generator end on a
Gem series base frame. US EPA TIer III.
M20CRW3
=
Northern Lights 20 kW (@ 60 Hz) commercial grade
marine generator set with a special generator end.
US EPA TIer III.
an engine number stamped
1
a generator plate, and a generator set plate.
2 3