Northern Lights OM844W3 User manual

OM844W3
For Models: M844W3, M844DW3, M844LW3,
and M20CRW3
OPERATOR’S MANUAL
Marine Generators | Marine Diesel Engines | Land-Based Generators

Diesel engine exhaust and some of its constitu-
ents are known to the State of California to cause
cancer, birth defects, and other reproductive harm.
— CALIFORNIA —
Proposition 65 Warning:
Northern Lights
4420 14th Avenue N.W.
Seattle, WA 98107
Tel: [phone]
Fax: [phone]
Copyright ©2013 Northern Lights, Inc.
All rights reserved. Northern Lights™, and
the Northern Lights logo are trademarks of
Northern Lights, Inc.
Printed in U.S.A.
PART NO.: OM844W3 11/13

OM844W3 11/13
1
Read this operator's manual thoroughly before starting to operate your equipment.
This manual contains information you will need to run and service your new unit.
Proprietary Information
This publication is the property of Northern Lights, Inc.
It may not be reproduced in whole or in part without the written permission of Northern Lights, Inc.
© Northern Lights, Inc. All rights reserved. Litho U.S.A. Publication number OM844W3 11/13
OPERATOR'S MANUAL
for Models
M844W3, M844DW3, M844LW3, and M20CRW3
Table of Contents
INTRODUCTION ...................................................... 2
Models Included ................................................... 2
Model Numbers .................................................... 2
Serial Numbers ..................................................... 2
WARRANTY ............................................................ 3
SAFETY RULES ....................................................3-7
LOCK OUT / TAG OUT PROCEDURES ............ 8
COMPONENT LOCATIONS
M844W3 Marine Generator (older baseframe) ..10
M844W3 Marine Generator (new baseframe)........... 11
M20CRW3 Commercial Generator ....................12
CONTROL PANELS .............................................13
OPERATING PROCEDURES
Break-in Period...................................................14
Before Starting....................................................14
Starting................................................................14
Operating ............................................................14
Stopping..............................................................14
Shutdowns and Alarms .......................................15
Spare Parts ..........................................................15
SERVICING SCHEDULE CHART .......................16
SERVICING
Lubrication - General..........................................18
Checking Oil.......................................................18
Oil Changes ........................................................18
SERVICING (continued)
Changing Oil Filter .............................................18
Air Filter .............................................................19
V-Belts ................................................................19
Valve Clearances.................................................19
Fuels - General....................................................20
Fuel Filters ..........................................................20
Bleeding the Fuel System ...................................21
Injector Service............................................ 22- 23
Injection Pump....................................................23
Cooling System - General...................................23
Cooling System Flushing....................................24
Heat Exchanger...................................................24
Raw Water Pump ................................................24
Generator Ends ...................................................24
Electrical System - General ................................24
Glow Plugs..........................................................25
Booster Batteries.................................................25
Battery Care ........................................................25
PTO Care ............................................................25
Winterizing / Out-of-Service ..............................25
TROUBLESHOOTING
Electrical .............................................................26
Engine .........................................................27 - 29
WIRING DIAGRAMS
AC Electrical ..............................................30 - 32
DC Electrical ..............................................33 - 40

OM844W3 11/13
2
Serial Numbers
Introduction
Unit Identication
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.
Failures can begin with minor problems that are
overlooked and become amplied 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.
W, D, L, C, 3
MODELS INCLUDED
This manual covers the operating instructions for:
M844W3 marine generator sets,
M844DW3 marine generator sets,
M844LW3 marine generator sets, and
M20CRW3 commercial generator sets.
NOTE: There are two versions of the 844W3 engine.
The standard engine is designated 844W3. The long-
stroke engine is designated 844LW3. You will need to
know which engine you have to use this manual and to
order parts.
W - New winding
D - Series Designation
L - Long stroke version
C - Commercial version
3 - Tier 3
++
Northern Lights marine diesel generator set with
an 844 engine and a PX-316K2 generator end.
M 844
M844W3
Your set has three serial numbers: 1an engine number stamped
on the block, 2a generator plate, and 3a generator set plate.
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.
Generator set serial number plate.
Northern Lights 16 kW marine diesel generator set
with an 844L engine and a PX-320K2 generator end.
Northern Lights marine diesel generator set with
an 844L engine and a PX-320K2 generator end.
M844DW3
M844LW3
Northern Lights 20 kW (@ 60 Hz) commercial grade
marine generator set with a special generator end.
M20CRW3
Model number of engine block
Bore Cylinders
84 mm 4
M - Northern Lights marine generator set
Model Numbers
Model numbers give the unit's application, block model, aspiration, and RPM:
My Northern Lights generator set MODEL number is:
=
=
=
=
Revised 11/8/13
Fill in the model number of your unit in the blank space provided.
This will give you a reference whenever service or maintenance is required:

OM844W3 11/13
3
Warranty
Revised 3/13/12
A warranty registration certicate is supplied
with your set. The extent of coverage is described
in the Limited Warranty Statement. We
recommend that you study the statement carefully.
NOTE: If the warranty is to apply, the servicing
instructions outlined in this manual must be
followed. If further information is needed, please
contact an authorized dealer or the factory.
Safety Rules
NOTICE: Accident reports show that careless use of engines causes a high percentage of accidents.
You can avoid accidents by observing these safety rules. Study these rules carefully and enforce them on the job.
IMPORTANT SAFETY INSTRUCTIONS.
Electromagnetic equipment, including generator sets
and their accessories, can cause bodily harm and
life threatening injuries when improperly installed,
operated or maintained. To prevent accidents be aware
of potential dangers and act safely.
READ AND FOLLOW ALL SAFETY
INSTRUCTIONS IN THIS MANUAL,
PRIOR TO THE INSTALLATION
OF ANY GENERATOR SET OR
ACCESSORY. KEEP THESE
INSTRUCTIONS FOR FUTURE
REFERENCE.
Recognize Safety Symbols and Instructions
In addition to the information found in this section, this
operator’s manual uses three different signal words to
outline potential dangers of a specic nature.
Follow All Safety Instructions
Carefully read and understand
all safety messages in this
manual and on your machine’s
safety signs. Keep signs in good
and clean condition. Replace
missing or damaged signs. Be
sure new equipment components and repair parts
include the current safety signs. For replacement signs,
proper placement of safety signs or clarication on any
safety issue, consult your Northern Lights dealer or the
factory.
There can be additional safety information contained
on parts and components from outside suppliers
that is not reproduced in this manual. Consult the
suppliers for additional safety information.
Learn how to operate the machine and how to use
the controls properly. Only trained personnel should
operate machines, or work on or around them.
Keep you machine in proper working condition.
UNAUTHORIZED MODIFICATIONS TO THE
MACHINERY MAY IMPAIR ITS FUNCTION
AND SAFETY PARAMETERS.
Prevent Bypass and Accidental Starting
!
WARNING
Do not start engine by shorting
across start terminal. Engine will
start if normal circuitry is bypassed,
creating a hazard by runaway
machinery.
Start engine only from operator’s station.
Handle Fuel Safely - Avoid Flames
!
WARNING
Diesel is highly ammable and should be treated
with care at all times. Do do not refuel while
smoking or when near sparks or open ame.
ALWAYS STOP ENGINE
BEFORE FUELING
MACHINE. Always ll
portable fuel tank outdoors.
Never fuel a hot engine.
!
DANGER
!
WARNING
!
CAUTION
DANGER indicates a hazardous situation which, if
not avoided, will result in death or serious injury.
WARNING indicates a hazardous situation which, if
not avoided, could result in death or serious injury.
CAUTION indicates a hazardous situation which,
if not avoided, could result in minor or moderate
injury.

OM844W3 11/13
4
Safety Rules
Revised 3/13/12
Operating equipment requires the full attention of
the operator. Do not use radio or music headphones
while operating machinery.
Practice Safe Maintenance
!
CAUTION
Understand all service procedures
before starting work. Keep area clean and dry.
Never lubricate, service, or adjust machine while it is
in operation.
Keep hands, feet and clothing away from power-
driven equipment. When shutting down an engine,
disengage all power and operator controls. Allow
the engine to cool completely before beginning any
service work.
Securely support any machinery elements that must
be raised for service work with support or lifting
machinery specically intended for that purpose.
Keep all parts in good conditions and properly
installed. Fix damage immediately. Replace any
worn or broken parts. Remove any build up of
grease, oil or debris.
Disconnect battery ground cable (-) before making
any adjustments or service work.
Stay Clear of Rotating Drivelines
!
DANGER
Entanglement in rotating drivelines can cause serious
injury or death. Keep shields in place at all times.
Make sure that rotating shields turn freely in pace
with the drivelines.
Do not wear loose tting equipment around rotating
drivelines. Stop the engine and make sure that all
moving parts have stopped
before making any adjustments,
connections, or performing
any other type of service to
the engine or other driven
equipment.
Prevent accidental discharge of starting uids by
storing all cans in a cool, safe place, away from sparks
or open ame. Store with cap securely on container.
Never incinerate or puncture a fuel container.
Prevent res by keeping machine clean of accumulated
trash, grease and debris. Always clean any spilled fuel
as swiftly as possible. Do not store oily rags, which
can ignite and burn spontaneously.
Be prepared if a re starts. Keep a rst aid kit and re
extinguisher handy. Keep emergency contact numbers
for re department, doctors, ambulance and hospital
near the telephone.
Service Machines Safely
!
DANGER
Do not wear a necktie, scarf,
necklace, rings or other
jewelry, or any loose clothing
when working near moving
parts. Tie long hair behind your head. If any of these
items get caught in moving machinery, severe injury or
death could result.
Check for any loose electrical connections or faulty
wiring.
Look completely around engine to make sure that
everything is clear before starting.
Wear Protective Clothing
!
WARNING
To prevent catching anything in moving machinery,
always wear close tting clothes and safety equipment
appropriate to the job.
Prolonged exposure to loud noise can cause hearing
loss or impairment.
Wear suitable authorized
hearing protection, such
as earmuffs or plugs to
protect against loud noises.

OM844W3 11/13
5
Safety Rules (Continued)
Revised 3/13/12
Install all Safety Guards
!
WARNING
Direct contact with rotating
fans, belts, pulley and drives
can cause serious injury.
Keep all guards in place at all
times during engine operation.
Wear close-tting clothes. Stop the engine and be
sure all fans, belts, pulleys and drives are stopped
before making adjustments, connections, or cleaning
near fans and their components.
Do not allow anything on your person to dangle into
or come in contact with a moving fan, belt, pulley or
drive. Fans can act as vacuums and pull materials
up from below, so avoid that area as well while in
service.
Safe Battery Handling
!
WARNING
Prevent Battery Explosions
Battery gas is highly
ammable. Battery
explosions can cause severe
injury or death. To help
prevent battery explosions, keep sparks, lighted
matches and open ame away from the top of battery.
When checking battery electrolyte level, use a
ashlight.
Never check battery charge by contacting the posts
with a metal object. Use a volt-meter or hydrometer.
Frozen batteries may explode if charged. Never
charge a battery that has not been allowed to warm to
at least 16oC (60oF).
Always remove grounded (-) battery clamp rst and
replace ground clamp last.
S ulfuric acid in battery electrolyte is poisonous and
strong enough to burn skin, eat holes into clothing and
other materials, and cause blindness if splashed into eyes.
To Avoid Hazards:
• Fill batteries only in well-ventilated areas.
• Wear appropriate eye protection and rubber gloves.
• Never use air pressure to clean batteries.
• Wear appropriate ventilation equipment to avoid
inhaling fumes when adding electrolyte.
• Do not spill or drip electrolyte.
• Use correct jump-start procedure if required.
If acid is spilled on skin or in eyes:
1. Flush skin with water.
2. Apply baking soda or lime to
help neutralize acid.
3. Flush eyes with water for
15-30 minutes.
4. Get medical attention
immediately.
If acid is swallowed:
1. DO NOT induce vomiting.
2. Drink large amounts of
water or milk, without
exceeding 2 liters
(2 quarts)
3. Get medical attention immediately
Battery posts, terminals, and related accessories
can contain lead and lead compounds, chemicals
known to the State of California to cause cancer and
reproductive harm. Wash hands after handling.
Handle Chemical Products Safely
!
WARNING
Direct exposure to hazardous
chemicals can cause serious injury.
Among the potentially hazardous
chemicals that may be used
with Northern Lights
products are lubricants,
coolants, paints and adhesives.
All potentially hazardous chemicals come with a Material
Safety Data Sheet (MSDS). The MSDS provides specic
details on chemical products, including physical hazards,
safety procedures and emergency response techniques
!
WARNING

OM844W3 11/13
6
Safety Rules (Continued)
Revised 3/13/12
Read and understand the MSDS for each chemical before
you start any job that includes it. Follow the procedures
and use appropriate equipment exactly as recommended.
Contact your Northern Lights dealer or Northern Lights
factory for MSDS’s used on Northern Lights products.
Work in Well Ventilated Areas
!
CAUTION
Exhaust fumes from engines contain carbon monoxide
and can cause sickness or death. Work in well ventilated
areas to avoid prolonged exposure to engine fumes. If it
is necessary to run an engine in an enclosed area, route
the exhaust fumes out of the area with an approved, leak
proof exhaust pipe extension.
Remove Paint Before Welding or Heating
!
WARNING
Hazardous fumes can be generated
when paint is heated by welding,
soldering or using a torch. To avoid
potentially toxic fumes and dust,
remove paint before heating.
• Remove paint a minimum of 100
mm (4 in.) from the
area that will be affected by heat.
• If paint cannot be removed, wear an approved respirator.
• If you sand or grind paint, use an approved respirator.
• If you use solvent or paint stripper, remove stripper
with soap and water before welding. Remove
solvent or paint stripper containers from the area.
• Allow at least 15 minutes for fumes to disperse
before welding or heating.
Do not use a chlorinated solvent in an area where welding
will occur. Work only in areas that are well ventilated.
Dispose of paint and solvent properly.
Service Cooling System Safely
!
WARNING
Opening a pressurized cooling
system can release explosive
uids and causing serious burns.
Before opening any pressurized
cooling system, make sure the
engine has been shut off. Do not remove a ller cap
unless it is cool enough to comfortably grip with bare
hands. Slowly loosen cap to relieve pressure before
opening fully.
Avoid High Pressure Fluids
!
WARNING
Relieve pressure prior to
disconnecting pressurized lines.
Escaping uid under pressure
can penetrate the skin causing
serious injury. Always relieve pressure before
disconnecting hydraulic or other pressurized lines.
Tighten all connections rmly before re-applying
pressure.
If searching for leaks, use a piece of cardboard.
Always protect your hands and other body parts from
high-pressure uids.
If an accident occurs, see a doctor immediately. Any
high pressure spray injected into the skin must be
removed within a few hours to prevent the risk of
gangrene or other infection.
Avoid Heating Near Pressurized Fluid Lines
!
WARNING
Flammable spray can be generated
by heating near pressurized uid
lines, resulting in severe burns and
bodily injury. Pressurized lines
can rupture when heat goes beyond the immediate
ame area. Do not weld, solder or use a torch or
open ame near pressurized lines or other ammable
uids.
Do Not Open High-Pressure Fuel System
!
DANGER
Many Northern Lights engines use high-pressure
fuel injection. High-pressure uid remaining in fuel
lines can cause serious injury. Do not disconnect or
attempt any repair of fuel lines, sensors, or other

OM844W3 11/13
7
Safety Rules (Continued)
Revised 3/13/12
material containing asbestos. Keep all bystanders
away from any area where asbestos dust may be
generated.
Use Proper Lifting Equipment and Techniques
!
WARNING
Lifting heavy components incorrectly
can cause severe injury or damage
to machinery. Avoid unbalanced
loads. Do not use lifting eyes. Lift the
generator set using lifting bars inserted
through the lifting holes on the skid.
Follow all recommended removal and installation
procedures in this and associated Northern Lights
manuals.
Use Proper Tools
!
CAUTION
Makeshift tools and procedures
can create safety hazards.
Always use appropriate tools for
the job.
Use power tools only to loosen threaded parts and
fasteners. For loosening and tightening hardware,
always use the correct sized tools.
Do not use US measurement tools on metric
fasteners, or vice versa. Use only service parts that
meet Northern Lights specications.
Dispose of Waste Properly
!
CAUTION
Disposing of waste improperly can threaten the
environment and lead to unsafe working conditions.
Potentially harmful waste used in Northern Lights
equipment can include oil, fuel, coolant, lters and
batteries.
Use leakproof containers to drain uid. Do not
use food or beverage containers that may mislead
someone into drinking from them.
Do not pour waste onto the ground, down a drain or
into any water source.
components between the high-pressure fuel pump
and nozzles on engines with high pressure fuel
systems.
ONLY AUTHORIZED TECHNICIANS
CAN PERFORM REPAIRS ON AN HIGH
PRESSURE FUEL INJECTION SYSTEMS.
Avoid Hot Exhaust
!
WARNING
Avoid exposure to and physical
contact with hot exhaust
gases. Exhaust parts and streams can reach high
temperatures during operation, leading to burns or
other serious injury.
Cleaning exhaust lters can also lead to exposure to
hot exhaust gas and the injury risk associated with
it. Avoid exposure to and physical contact with hot
exhaust gases when cleaning exhaust lters.
During auto or manual/stationary exhaust lter
cleaning operations, the engine will run at
elevated temperatures for an extended period of
time. Exhaust parts and streams can reach high
temperatures during operation, leading to burns or
other serious injury.
Avoid Harmful Asbestos Dust
!
WARNING
Inhaling asbestos bers may cause
lung cancer. Avoid breathing any
dust that may be generated when
handling components containing
asbestos bers, including some
gaskets.
The asbestos used in these components is usually
found in a resin or otherwise sealed. Normal
handling of these components is not dangerous,
as long as airborne dust containing asbestos is not
generated.
Avoid creating dust. Never use compressed air for
cleaning. Avoid brushing or grinding materials
containing asbestos. When servicing, wear an
approved respirator. A special vacuum cleaner is
recommended to clean asbestos. If this vacuum is
not available, apply a mist of oil or water on the

OM844W3 11/13
8
General Policy
To avoid dangerous or hazardous situations, refrain from
any of the following:
• Removing or bypassing a guard or other safety device
• Placing any part of your body in a position where you
could be caught by moving machinery.
• Cleaning or oiling machinery when in operation.
• Adjusting circuits, chillers, pumps, air handlers, valves,
circuit breakers or fans while in operation.
• Working on piping or high pressure systems.
Lock Out/Tag Out Instructions -
Electrical Equipment
Be sure the equipment’s ON/OFF switch is in the OFF
position and is unplugged from any electrical source before
attempting to perform any type of work on the equipment.
Obtain an electrical plug cap cover with a lockset. Secure
the plug terminal end using the electrical plug lockout cap.
Lock the cap and retain the key.
If the equipment is directly wired into an electrical box with
a shut off switch, obtain a lock pad and/or the appropriate
colored tags and place the lock and tag through the shut
off lever. Retain the key until the repair is completed and
the machine is safe to start. Be certain the shut off lever
is in the OFF position before restarting. NEVER give a
lock out key to unauthorized personnel.
If the equipment is directly wired into an electrical box
without a shut off switch and lock out capability, then a
circuit breaker lock out will be required. Obtain a circuit
lock and tag set. Install the lock onto the circuit breaker
box. Ensure the unit ON/OFF switch is in the OFF position
before restarting.
Lock Out/Tag Out Instructions -
Pneumatic and Hydraulic Equipment
For servicing pneumatic and hydraulic equipment, the
following additional procedures must be implemented,
following completion of lock out/tag out procedures for
the unit to be serviced:
Shut off air, water or supply valves at the equipment to
be serviced.
Check the local bleed-off point for completed release of
pressurized air, water or oil.
If shutting off of air, water or other material cannot be
achieved at the local supply valve, shut off valves further
back in the system and re-check the bleed-off point until
complete shut-off is achieved.
Afx a DO NOT OPERATE tag to each valve handle that
requires shut off. Each DO NOT OPERATE tag must be
signed and dated by the authorized technician servicing
the equipment.
Lock Out/Tag Out Instructions -
Air Hose Connected Pneumatic Equipment
Equipment connected to the compressed air system
through an air hose with a detachable tting must be
shutdown and unplugged. Excess air must be bled prior
to removing the air hose, prior to any maintenance or
repair activities.
Afx a DO NOT OPERATE tag to the air hose near the
detachable tting. Each DO NOT OPERATE tag must be
signed and dated by the authorized technician servicing
the equipment. Check that the equipment cannot be
operated by activating the ON switch.
Stored Energy
Immediately after applying Lock Out or Tag Out devices,
ensure that all potentially hazardous stored or residual
energy is relieved, disconnected, restrained and otherwise
rendered safe.
Verication of Isolation
Verify the machinery or equipment is actually isolated and
de-energized prior to beginning work on a machine or on
equipment that has been locked out.
Restarting Procedures
Follow the procedures below prior to restoring energy:
• Ensure that all machinery or equipment is properly
reassembled. Inspect the machinery or equipment to
verify non-essential items have been removed.
• Ensure that all personnel are safely outside danger
zones. Notify personnel that lock out/tag out devices have
been removed and energy will be reapplied.
• Only authorized personnel may remove lock out/tag out
devices or notices.
Scope
During maintenance, repairs or retooling of a Northern Lights generator set, simply turning the machine off or unplugging
it while it is being worked on does not give enough protection to others who are not performing the maintenance or
repair. Many serious accidents happen when someone thought the machine was turned off, or all of its energy was
safely blocked or released.
!
CAUTION
!
WARNING
!
WARNING
!
WARNING
!
WARNING
!
CAUTION
!
CAUTION
Lock Out / Tag Out Procedures
Added 3-13-12

OM844W3 11/13
9
Notes

OM844W3 11/13
10
1. DC Circuit Breaker
2. Coolant Recovery Tank
3. Secondary Fuel Filter
4. Fuel Return Line
5. Fuel Injector
6. Oil Fill (Top)
7. Coolant Fill
8. Fresh Water Pump
9. Injection Pump
Marine Generator Component Locations
19. Oil Filter
20. Lube Oil Drain
21. Fuel Lift Pump
22. Control Panel Plug-in
23. AC Circuit Breaker for
Automatic Voltage Regulator
24. Expansion Tank/Exhaust
Manifold/Heat Exch.Tank
Service Side
5
Non-Service
Side
5
Figure 1A and 1B: M844W3
25. Coolant Drain
26. Wet Exhaust Elbow
27. Junction Box
28. Starter
29. Alternator
30. Belt Guard
31. Coolant Thermostat (behind)
32. Water Temperature Sender
10. Oil Fill (Side)
11. Raw Water Pump
12. Raw Water Inlet
13. Vibration Mount
14. Oil Pressure Sender
15. Freshwater Block Drain
16. Fuel Inlet Line
17. Fuel Return Line
18. Oil Dipstick

OM844W3 11/13
11
1. DC Circuit Breaker
(not visible. Callout for
approximate location)
2. Coolant Recovery Tank
3. Secondary Fuel Filter
4. Fuel Return Line
5. Fuel Injector
6. Oil Fill (Top)
7. Coolant Fill
8. Fresh Water Pump
Marine Generator Component Locations
19. Oil Filter
20. Lube Oil Drain
21. Fuel Lift Pump
22. Control Panel Plug-in
(not visible. Callout for
approximate location)
23. AC Circuit Breaker for
Automatic Voltage Regulator
24. Expansion Tank/Exhaust
Manifold/Heat Exch.Tank
Service Side
5
Non-Service
Side
5
Figure 1A and 1B: M844W3
2
122
45
8
9
7
6
3
11
12
13
14
10
15
18
16
17
19
20
21
22
25. Coolant Drain
26. Wet Exhaust Elbow
27. Junction Box
28. Starter
29. Alternator
30. Belt Guard
31. Coolant Thermostat (behind)
32. Water Temperature Sender
7
11
31
32
24 27
28
13
29
30
26
25
9. Injection Pump
10. Oil Fill (Side)
11. Raw Water Pump
12. Raw Water Inlet
13. Vibration Mount
14. Oil Pressure Sender
15. Freshwater Block Drain
16. Fuel Inlet Line
17. Fuel Return Line
18. Oil Dipstick
added 3-28-11

OM844W3 11/13
12
Commercial Generator Component Locations
1. DC Circuit Breaker
2. Secondary Fuel Filter
3. Fuel Return Line
4. Fuel Injector
5. Oil Fill (Top)
6. Coolant Fill
7. Fresh Water Pump
8. Injection Pump
9. Oil Fill (Side)
19. Control Panel Plug-in
20. AC Circuit Breaker for
Automatic Voltage Regulator
21. Expansion Tank/Exhaust
Manifold/Heat Exch.Tank
22. Coolant Drain
23. Wet Exhaust Elbow
Figure 2A and 2B: M20CRW3
24. Junction Box
25. Starter
26. Alternator
27. Belt Guard
28. Coolant Thermostat (behind)
29. Water Temperature Sender
10. Raw Water Pump
11. Raw Water Inlet
12. Vibration Mount
13. Oil Pressure Sender
14. Freshwater Block Drain
15. Oil Dipstick
16. Oil Filter
17. Oil Drain
18. Fuel Lift Pump

OM844W3 11/13
13
Control Panels
Figure 3-B: Series 3 Generator Control Panel
Figure 3-A: Series 1-B Generator Control Panel
Figure 3-C: Series 4 Generator Control Panel
1. SHUTDOWN BYPASS-PREHEAT SWITCH
Two functions are built into this switch: the preheat-
ing of the engine, and bypassing of the engine safety
shutdown circuit. Hold switch in the ON position
10 - 20 seconds before starting the engine, and
continue holding on during engine cranking. Release
the switch as soon as the engine is running. Holding
the switch on too long can burn out the heater element.
2. ENGINE CONTROL SWITCH
To start the engine, hold this switch in the START
position until the engine is running.
NOTE: Excessive cranking of marine sets equipped
with water lift mufer systems can cause engine
damage. See page 7.
After the engine starts, release the switch and it will
return to RUN position. To stop the engine, hold the
switch in the STOP position until the engine has
completely stopped.
NOTE: The rocker switch is used on Series 1 panels
only, and has a light that glows when the set is running.
3. HOUR METER
Keeps track of engine running time.
4. OIL PRESSURE GAUGE
Shows the oil pressure in the engine lubricating system.
5. ENGINE TEMPERATURE GAUGE
Registers the temperature of the engine coolant.
6. D.C. VOLTMETER OR AMMETER
When the engine is stopped, the voltmeter indicates the
condition of the battery. When the engine is running, the
voltmeter indicates the voltage output of the alternator.
For Series 4 Control Panels Only:
7. A.C. VOLTMETER
Shows the generator output voltage.
8. FREQUENCY METER (Hertz)
The frequency meter indicates alternating current
frequency: 60 Hz (1800 RPM), or 50 Hz (1500 RPM).
9. AMMETER/VOLTMETER SELECTOR
SWITCH
Used to check voltage and current of each phase.
10. A.C. AMMETER
Shows the generator load on each phase. The phase is
selected with the Ammeter Selector switch (Item 9).

OM844W3 11/13
14
BREAK-IN PERIOD
1. The rst 100 hours on a new or reconditioned
engine are critical to its life and performance.
2. Operate the engine under various conditions,
particularly heavy loades with minimal idling, to
help seat engine components properly.
3. Frequently check the engine temperature and oil
pressure gauges (sets with Series 3 or 4 panels).
4. Oil consumption is greater during break-in as
piston rings take time to seat.
5. Break-In Oil Changes: Change engine oil and
lter at 50 hours. Change oil and lter again at
100 hours (consult Lubricants section for oil
recommendation), then at every 250 hours.
BEFORE STARTING
1. Check the water level by removing the pressure
cap from the expansion tank or radiator. In order to
give the cooling water an opportunity to expand, the
level should be about 1 in. (2.5 cm) below the ller
cap sealing surface when the engine is cold.
CAUTION: Use protective clothing and open the ller
cap carefully when the engine is warm to prevent
burns.
2. Check the oil level in the crankcase with the
dipstick. The oil level must be in the wafed area on
the stick. Never allow the level to go below this area.
Always add the same viscosity of oil as is already in
the crankcase.
3. Check the fuel tank level and open any fuel valves.
4. Close the sea-cock; check, clean, and reassemble the
sea strainer and re-open the sea-cock.
5. Place the battery switch in the ON position.
6. NOTE: The battery switch must always be kept
ON while the engine is running. If the switch is
turned OFF while the engine is running, the
battery charging regulator could be ruined.
STARTING
1. Hold the Shutdown Bypass-Preheat switch in the ON
position for 10 to 20 seconds before starting a cold
engine. Holding the switch too long can burn out the
glow plugs. This step is not necessary if the engine is
already warm.
2. While holding the Shutdown Bypass-Preheat switch
in the ON position, push the Engine Control switch
to the START position.
3. As soon as the engine starts, release both switches. Do
not crank the starter for more than 10 seconds
consecutively. If the engine fails to start with the rst
attempt, be sure that it has stopped completely (wait at
least 30 seconds) before re-engaging.
NOTE: Excessive cranking of the starter on Marine
sets equipped with a water lift mufer can cause engine
damage. If the engine does not start after three 20-
second cranks, remove the impeller from the raw water
pump. This will prevent the mufer from lling with
water and backlling the exhaust line and engine. Once
the engine starts, shut it off immediately and
re-install the impeller. Re-start the engine and check
the exhaust overboard outlet for gushes of water.
OPERATING
1. Units with Series 3 and Series 4 Control Panels:
check gauges often. Oil pressure must be above 15
PSI. The D.C. voltmeter should read between 11 and
15 volts at 80°F (25°C) ambient temperature. The
water temperature gauge on Marine sets must be
below 200°F (94°C). Normal coolant temperature
is 167° to 194°F (75°C to 90°C). Check the A.C.
voltage and frequency meters (Series 4 panel). If the
gauges deviate from normal levels, shut down the
generator set and investigate.
2. Let the unit run unloaded for a three to ve minute
warm-up period.
3. Apply electrical load.
STOPPING
1. Remove electrical load from the generator set.
2. Run the engine for a 3 to 5 minute cool down period.
3. Hold the Engine Control switch to the STOP position
until the engine comes to a complete stop.
4. Shut off the seacock, fuel valve, and battery switch.
Operating Procedures
updated page 1-9-13

OM844W3 11/13
15
SHUTDOWNS AND ALARMS
1. Your unit is tted with a system to protect it from
high water temperature or low oil pressure.
a. Generator sets have shutdown systems to stop the
engine. They have no warning horns.
b. Other alarms and shutdowns are available as
optional equipment.
NOTE: Do not rely on your warning to the
exclusion of careful gauge monitoring. Watching
your gauges can prevent damage to the unit and
dangerous power losses.
2. Do the following when your warning or shutdown
system is activated:
a. Engage the preheat switch to check the
temperature gauge.
b. If above 205°F (96°C), use the Trouble Shooting
Guide on page 20 to isolate the cause of the
overheat.
CAUTION: Do not remove the water ll
cap of an overheated engine. Escaping high
temperature steam can cause severe burns.
Allow the engine to cool and then remove the cap
slowly using protective clothing.
c. Make repairs. Restart your Marine set after the
temperature gauge registers below 200°F (94°C).
d. Watch the temperature gauge regularly and
turn off the unit if the temperature rises above
205°F (96°C) on units. Repeat troubleshooting.
3. If shutdown is activated and the temperature gauge
shows temperature within normal temperature range:
a. This shutdown could have happened because of a
too high exhaust temperature. This could have
been caused by a damaged impeller or a
partially blocked sea water strainer. Check the
sea water strainer rst. If it is clear, then check
the condition of the sea water pump impeller.
b. Check the engine crankcase oil level.
c. If the oil level is low, ll with recommended
lubricating oil and restart. Watch the oil pressure
gauge carefully and shut off the engine if it does
not show a normal reading (20-60 PSI) after a
few seconds of operation.
d. If the oil level is normal, DO NOT restart the
engine. Call your dealer for assistance.
SPARE PARTS
1. Northern Lights recommends that you keep the
following spare parts on hand for eld service. The
parts are available from your local Northern Lights
dealer.
Some marine models already have “On-Board-Kits,”
a handy box that contains the most common parts
you will need.
2. All owners should have the following spares:
a. Primary and secondary fuel lter elements
b. Oil lters
c. Air lter
d. Alternator belt
e. Thermostat and gaskets
f. Seawater pump impeller & gaskets
g. Glow plug
h. Injector and washer
3. If your set is operating a long distance from a
servicing dealer, add the following:
a. Complete set of injectors
b. Copper washers for injector change
c. Complete set of glow plugs
d. Fuel lift pump
Operating Procedures

OM844W3 11/13
16
The Servicing Schedule Chart below shows the service schedule required for proper maintenance of your generator
set. More detailed coverage of each Service Point (SP) is listed on the page noted in the ‘page’ column.
DAILY:
SP1 Check oil level in engine
SP5 Check V-belt tension
SP7 Check primary fuel lter
SP13 Check coolant level
Check sea strainer
Check raw water pump for leaks
SP18 Check electrolyte in batteries
AFTER FIRST 50 HOURS:
SP2/3 Change engine oil and lter
SP6 Adjust valves
AFTER FIRST 100 HOURS:
SP2/3 Change engine oil and lter
EVERY 250 HOURS:
SP2/3 Change engine oil and lter
SP4 Check air cleaner
SP19 Check state of charge of batteries
EVERY 500 HOURS:
SP8 Change primary fuel lter element
SP9 Change secondary fuel lter
SP22 Inspect condition of exhaust elbow
EVERY 1000 HOURS:
SP4 Change air cleaner element
SP6 Check valve clearances
SP11 Check injectors
SP17 Change impeller
EVERY 2500 HOURS:
SP12 Check fuel injection pump
SP14 Check and ush cooling system
SP15 Check and clean heat exchanger
1) Perform all maintenance once a year even if hour level has not been reached.
2) Consult manufacturer's maintenance schedule, note on chart.
3) Whenever necessary.
4) More often if necessary.
5) After rst 50 hours, then at 100 hours, then at every 200 hours.
Servicing Schedule Chart
SERVICE 50 250 500 1000 2500
POINT PAGE OPERATION DAILY Hours Hours Hours Hours Hours
ENGINE:
SP1 12 Check oil level •
SP2 12Change engine oil 1) 5) ••
SP3 12 Change lube oil lters 1) 5) • •
SP4 13Check air cleaner 1) 4) •
SP5 13Check V-belt tension •
SP6 13Check valve clearances 1) 2) •
FUEL SYSTEM:
SP7 14 Check primary lter (Racor) 2) 3) •
SP8 14 Change primary lter element (Racor) 2) 3) •
SP9 14 Change secondary fuel lter 1) 3) •
SP10 15Bleed the fuel system 3)
SP11 16 - 17 Check injectors 1) 3) 6) 7) •
SP12 17 Check fuel injection pump 7) •
COOLING SYSTEM:
SP13 17 Check coolant level •
SP14 18 Check and ush cooling system •
SP15 18 Check and clean heat exchanger •
SP17 18 Change impeller in raw water pump 1) 3) •
SP22 Inspect condition of exhaust elbow 4) •
ELECTRICAL SYSTEM:
SP18 19 Check electrolyte level in batteries •
SP19 19 Check condition of batteries with hydrometer 1) 4) •
DRIVEN EQUIPMENT:
SP20 19 Clutch and PTO service 2)
OUT OF SERVICE:
SP21 19 Winterizing or out-of-service 3)
6) Clean injection nozzles every 1500 hours.
7) For EPA emission standards fuel nozzle needs to be cleaned every
1500 hours, the fuel nozzle and fuel pump need to be cleaned,
adjusted, or repaired every 3000 hours, and the quality guarantee for
these parts is 1500 hours or 2 years.

OM844W3 11/13
17
Service Record Notes

OM844W3 11/13
18
Servicing
LUBRICATION - GENERAL
1. Use only clean, high quality lubricants stored in
clean containers in a protected area.
2. These lubricants are acceptable:
a. API Service CC/CD/CE single viscosity oils.
b. API Service CC/CD/SF multi-viscosity oils.
3. Use the proper weight oil for your average
operation temperature.
Figure 4: Lube Oils
4. Some increase in oil consumption may be
expected when SAE 5W and SAE 5-20W oils are
used. Check oil level frequently.
5. Never put additives or ushing oil in crankcase.
SP1. CHECKING OIL LEVEL
1. Check the oil level in the crankcase with the dipstick
(Fig. 5). The oil level must be in the wafed area
on the stick. Never allow the level to go below this
area. Follow the lubrication recommendations above.
SP2. OIL CHANGES
1. The set is delivered with special break-in oil.
Change the engine oil and oil lter after 50 hours
of operation. Use Service CC 30 weight oil during
the rst 100 hours.
2. Change the oil and lter again at 100 hours using the
oil recommended in the above diagram. After this,
change oil and lter every 250 hours.
3. During intermittent cold weather operation, change
oil every 100 hours or six weeks, whichever comes
rst.
4. Change oil at the end of each season and the
beginning of each season.
5. Change oil when engine is warm.
6. Dispose of waste oil in an approved manner.
7. Never use a ushing oil.
8. Loosen the clamp on the oil change tube. Remove
cap. Drain oil. Replace the cap and tube.
9. Rell engine with recommended oil for the season.
10. Engine capacity with new oil lter is:
844W3 and 844LW3 – 2.1 gallons
(8.2 liters)
SP3. CHANGING LUBE OIL FILTER
1. Change the lube oil lter every 250 hours.
2. Use a lter wrench to remove old lter. Dispose of
lter in approved manner.
3. Make sure the gasket from the old lter is removed
and discarded. Clean mount face.
4. Spread a thin lm of engine oil on the rubber gasket
on the new lter and screw it on nipple until gasket
meets the sealing surface.
5. Using hands only – no wrench – tighten lter
one-half turn farther. Overtightening can do
damage to lter housing.
6. Fill engine with recommended oil. Start engine and
check for leakage. Stop engine, wait 3 minutes, and
check oil level. Add additional oil if necessary.
7. Oil lter part number is:
844W3 and 844LW3 – #24-03100
Air Single Multi-
Temperature Viscosity Viscosity
Above 32°F SAE 30W SAE 15-40W
(0°C)
-10 to 32°F SAE 10W SAE 10-30W
(-23 to 0°C)
Below -10°F SAE 5W SAE 5-20W
(-23°C)
Figure 5
Figure 6