Precision Power DG4LN User manual

OWNER’S MANUAL
Air-cooled diesel engine generator set
PREFACE
The following manual is only a guide to assist you and is not a complete or
comprehensive manual of all aspects of maintaining and repairing your generator．The
equipment you have purchased is a complex piece of machinery．We recommend that
you consult with a dealer if you have doubts or concerns as to your experience or
ability to properly maintain or repair your equipment．You will save time and the
inconvenience of having to go back to the store if you choose to write or call us
concerning missing parts，service questions，operating advice，and/or assembly
questions．

1
Our air-cooled diesel generators have some of the following features：
●Lightweight construction
●Air cooled
●Four-stroke diesel internal combustion engine
●Direct fuel injection system
●Recoil starter or an optional electric starter
●Large fuel tank
●Automatic voltage stabilizer
●NFB circuit protector
●AC and DC outputs
●Low oil pressure sensor
The air-cooled diesel generators are widely used when electrical power is
scarce．Our welders provide a portable mobile solution in supplying power for field
operations during project construction．Some other known applications include pipeline
construction and metal welding when electrical power is not available．
This manual will explain how to operate and service your generator set．
If you have any questions or suggestions about this manual．please contact your
local dealer or us directly． Consumers should notice that this manual，might differ
slightly from the actual product as more improvements are made to our
products．Some of the pictures in this manual may differ slightly from the actual
product as well．We reserves the right to make changes at any time without notice
and without incurring any obligation．
TABLE OF CONTENTS
CHAPTER 1 TECHNICALSPECIFICATIONSANDDATA·······················2
CHAPTER20PERATINGTHEDIESELGENERATOR··························4
2-l General main points of safety during operation of the generator set·· 4
2-2 Preparation before operation········································6
2-3 Checking the operation of the diesel engine·························9
2-4 Starting the generator set··········································· 9
2-5Proper operation of the generator set································ 12
2-6 Loading···························································12

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2-7 Stopping the generator············································ 14
CHAPTER 3 MAINTENANCE·············································15
3-1 Maintenance schedules··········································15
3-2 Storing along periods of time······································17
C H A PT E R 4 O V E RH A U L I NG A N D T R O U B L E S HOOTING···················18
4-l Overhauling and troubleshooting procedures························ 18
4-2 Questions and answers············································18
CHAPTER 5 PART LISTINGS·············································19
REMOTE CONTROL INSTRUCTIONS····································· 24
LIMITED WARRANTY····················································25
APPENDIX······························································32
Figure 1．Overall of the DG4LN

3
Figure 2．Overall view of the DG6LN
CHAPTER 1 TECHNICAL SPECIFICATIONS AND DATA
Technical specifications and data(in English units)
Model
Item
DG4LN
DG6LN
DG6LN-3P
Generator
Generator type
Single phase
Three phase
Excitation
Self-excitation voltage
Voltage system
Condenser compensation system
Frequency(Hz)
50
60
50
60
50
60
Rated power(HP）
3.75
4.69
6.17
7.37
6.17
7.37
AC Rated Voltage(V1)
110,220, 230，240，110/220，120/240
220/380
DC Rated output(V-A)
12-8.3
Speed(rpm)
3000
3600
3000
3600
3000
3600
Power factor(cosΦ)
1.0
0.8
Di es el en gi ne
Engine model
178F
186F
186F

4
Type
Single-cylinder,vertical，4-stroke，air-cooled，direct-injection
Output
Continuous(HP)
4.6
5.9
7.7
8.85
7.7
8.85
Maximum(HP)
5.4
6.6
8.5
9.85
8.5
9.85
Bore X Stroke(in．)
3.07×2.44
3.39×2.76
3-39×2.76
Displacement(cu.in.)
18.1
24.8
24.8
Lube-Oi capacity(oz.)
37.17
55．75
55.75
Fuel tank capacity(USgal)
3.96
3.96
3.96
Dry weight(lbs)
304
352
352
Dimensions(L×W×H)
(in.)
33.3×20．9×27．8
36.2×20.9×27.8
36.2×20.9×27.8
Model
Item
DG4LN
DG6LN
DG6LN-3P
Generator
Generator type
Single phase
Three phase
Excitation
Self-excitation voltage
Voltage system
Condenser compensation system
Frequency(Hz)
50
60
50
60
50
60
Rated power(kW）
2.8
3.5
4.6
5.5
4.6
5.5
AC Rated Voltage(V)
110,220, 230，240，110/220，120/240
220/380
DC Rated output(V-A)
12-8.3
Speed(rpm)
3000
3600
3000
3600
3000
3600
Power factor(cosΦ)
1.0
0.8
Diesel engine
Engine model
178F
186F
186F
Type
Single-cylinder,vertical，4-stroke，air-cooled，direct-injection
Output
Continuous(kW)
3.4
4.4
5.7
6.6
5.7
6.6
Maximum(kW)
4.0
4.9
6.3
7.34
6.3
7.34

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Bore X Stroke(mm)
78×62
86×70
86×70
Displacement(cc)
296
406
406
Lube-Oi capacity(L)
1.1
1.65
1.65
Fuel tank capacity(L)
15
15
15
Dry weight(kg)
138
15
160
Dimensions(L×W×H)
(mm)
845×530×705
920×530×705
920×530×705
CHAPTER 2 OPERATING THE DIESEL GENERATOR
2-1 General main points of safety during operation of the generator set．
In order to operate the generator set safely．please follow all the instructions provided
in this manual carefully．Doing so otherwise may lead to accidents and or equipment damage．
2-1.1 Fire prevention
The proper fuel for the diesel generator set is light diesel fuel．Do not use gasoline，
kero- sene and or other fuels other than light diesel fuel．Keep all flammable fuels away
from the generator as the generator may spark and ignite these gases．In order to prevent
fires from occurring and to provide enough ventilation for people and the machine，keep the
diesel generator at least 1 ．5meters or 5 feet away from buildings and or other
equipment．Always operate your diesel generator on a level site．If the generator is operated
on an incline，the lubricating system within the engine will not perform well and may lead
to failure of the engine．
2-1.2 Prevention from inhaling exhaust gases
Never inhale exhaust gases emitted by the engine．The exhaust gases contain toxic carbon
monoxide．Never operate your generator in places with poor ventilation．In order to operate
this machinery indoors，a suitable ventilation system for the building is required to draw
the poisonous exhaust gases out．

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2-1.3 Prevention from accidental burns
Never touch the muffler and its cover when the diesel engine is running．Never touch the
muffler and cover after the diesel engine has been used，as the muffler remains hot for a
good period of time．
2-1.4 Electrics shock and short circuits
Never touch the generator if the generator is wet．Also never touch the generator if your
Hand is wet．Never operate your generator if the weather conditions call for any type of
precipitation such as rain，snow or fog．To prevent electrical shocks，the generator should
be grounded．Use a lead to connect the grounding end of the generator to the grounding surface
of choice．
2-1.5 Other safety points
Before operating this generator, all operators should have a good knowledge of how to break
the circuit if any accidents．occur．Also，all operators should be familiar with all the
switches and functions of the generator before using this machine．While operating the
generator，wear safe shoes and suitable clothes during operation．Always keep children and
animals away from the generator．
2-1.6 Battery
The electrolytic liquid of the battery contains sulfuric acid．In order to protect your eyes，
Skin and clothing，wear protective gear when working with the battery．If you come in contact
with the electrolytic liquid，wash it immediately with clean water．Also．if the electrolytic
liquid comes in contact with your eyes，see a doctor immediately.
Note：When connection devices to the generator,make sure all other devices are
rated lower than the generators output．Any generator socket should not be
overloaded over its regulated limit

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2-2 Preparation before operation
2-2.1 Fuel choices and fuel treatment
a．After purchasing fuel，put it into a drum
and let it sit for 3-4 days．
b．3-4 days later，insert half of the fuel
sucker into the drum(water and impuri-
ties stay in the lower portion of the drum)
Note：
Never smoke near the opening of the
fuel tank．Do not let sparks get near the
fuel or fuel tank and do not overfill
tank．After filling，tighten the fuel cap．
Fuel tank
Use only light diesel fuel．The fuel
should be filtered clean．Never let dust
and water mix with fuel tank Use only
light diesel fuel．The fuel should be
filtered clean．Never let dust and water
mix with fuel in the fuel tank．Otherwi-
se it will clog the fuel lines and oil
nozzles ．It may also damage your
pressure pump．
Note：It is dangerous to overfill the fuel
tank．Never exceed the red piston in the
filter．
Air filter element
Do not wash the air filter．The elem-
ent is made of dry material，which
does not permit washing．When the
output of the diesel engine is bad or
the color of the exhaust gas is
abnormal，replace the air filter elem-
ent．Never start the diesel engine
without the air filter．

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2-2.2 Fill engine oil
Engine oil is the most important factor in determining the life of your generator engine．If
you use poor engine oil or if you don’t change the oil regularly．the piston and cylinder
will wear easily or seize up．Also，the life of the other pages in your engine such as bearings，
and other rotating parts will shorten considerably．
Time to change engine oil
Although there is an alarm system to check for low oil pressure，it is always a good idea
to check the amount of oil inside the engine.If the oil level is low,fill it before starting
the engine．A good time to drain the oil from the engine is when the diesel engine is still
hot．If the engine is fully cooled，it is more difficult to drain all the oil out or some
impurities will remain in the engine．
Fabrication Oil Filling Inlet
Put the generator set in level state．Fill the oil into the oil-
filling inlet．At the time of checking the oil level，it is nec-
essary only to lightly insert the oil ruler．Please pay attention
to that you should not rotate the oil ruler．
Type
Volume
186FG
Volume(L)
England Galion
1.65 (0.36)
Warning：Don't fill engine oil when diesel is operating.
A.P.I. Diesel engine maintenance classification

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2-2.3 Check air filter
(1)Loosen the butterfly nut，take the cover
of the air filter off and take the air
filter element out．
Do not use detergent to wash the air filter
element．When the performance of the eng-me
decreases or when the color of the exhaust
gases is bad，exchange the filter
element．Never start the engine without the
air filter as foreign objects may enter the
intake and damage the engine．
(2)After replacing the air filter element，
re- place the cover and tighten the
butterfly nut firmly.
2-2.4 Checking the generator welder
Before starting the generator，make sure
the air switch is in the“off”position．
Starting the generator with the switch in
the the “on”switch is very dangerous.
The generator should be grounded in order
to prevent electric shock.
Use dry compressed air (with pressure about
1.96 x 105 Pa) to blow the dust out in the
electric control cabinet and at the surface
of the generator．Check to see how clean the
surface of the sliding ring is．Check the
pressure of the carbon brush．Also，check
whether the position of the carbon brush at
the slide rig is correct and the fixture is
reliable with a good contact.
According to the electric wiring diagram，
check to see whether the connecting wire is
correct and the connected place is firm．
Use a 500 MΩ meter to measure the
insulation resistance of the electrical
part．The resistance should be less than
2MΩ When measuring devices，make sure the
capacitor is turned off．Otherwise,it will
bum the capacitor．(For silent set．the
inspection may not be carried out)．
2-2.5 The fuel and oil in a new engine is
drained before sold．Before you start the
engine，please fill the fuel tank snd oil
first．Then，check to see if there are air
bubbles in the engine．If there are，follow
these procedures．Loosen the connecting nut
between the oil injection pump and oil
pipe．Bleed the air from the system until
there are no more bubbles．Then replace the
connecting nut and tighten it．
2-3 Checking the operation of the

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diesel engine
2-3.1 Low-pressure alarm system．
The diesel engines have a low-pres-
sure sensor system where if the oil
pressure drops to low，the sensor will
shut the engine off．The purpose of
having this system is to ensure that
the engine does not seize up．If there
is not enough oil in the engine，the
temperature of the oil will be raised
too high．On the contrary，if there
is too much oil in the engine，the
engine oil can slow the engine down
considerably．
(Note：The 2 GF-L model cannot au-
tomatically stop itself)
2-3.2 How to open the case door/cover
(1)Open the case door：turn the handle
counterclockwise and open the door
Do these checks daily．
(2)Loosen the outer cover bolt of the air
filter and outer cover of the oil
nozzle．And then check the air filter．
(3)Check t he outer cover of the oil nozzle.
Loosen the butterfly nut and open the
outer cover．
2-3.3 Engine break in
When you purchase a brand new
engine，the engine must be properly
broken in．The break in period is
about 20 hours．
（1）Avoid overloading the engine when
brand new．
（2）Change the engine oil according
to specifications．An oil change for
a brand new engine is abom-20
hours or every month ，an older
engine，the oil change is about 100
hours or three months．
2-4 Starting the generator set
2-4.1 Manual starting．
Start the engine in accordance with pr-
ocedures below：
（1）Put the fuel switch in the“ON”
position．
(2)Turn the handle of the engine to the
“RUN”position．
(3)Pull the recoil starter handle out
until you feel resistance．It will reset to
its original position automatically．The
handle should be reset into its recoil
device slowly to prolong the life of the
life of the engine starter．
(4)In cold climate，it is difficult to
start the engine．To remedy this，pull the
rubber plug out from the rocker of the
diesel engine and fill 2 ml of engine
oil．Before starting，put the rubber plug

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back in place．If you don’t put the rubber
plug back in place，rain，dust and other
dirt call enter into the diesel engine．It
will cause the parts inside the diesel
engine to wear quickly and lead to engine
failure．
2-4.2 Electric starting
The procedures for preparing to start eh
engine are the same as the manual starting
engine．
2-4.3 Battery
1．Insert key into ignition and put it in
the“off”position．
2．Put the speed handle in the“Run”
position．
3．Turn the start switch clockwise to the
“START”position；to set the silent
type，first turn it clockwise to the
“RUN” （ ON ）position for 1-2
seconds ．The electromagnetic iron
will be triggered，now turn it clock-
wise to the “START”position．
4．After the diesel engine is started，
re- move your hand from the switch
handle；the switch will automatically
reset itself to the“ON”position．
5．If the engine is not starting after 10
seconds of cranking ，wait about 15
seconds before trying it again．If you
crank to long，the voltage of the bat-
tery will drop．This can lead to im-
proper ignition．When the diesel en-
eigne is operating，let the ignition
retain on the“ON”position．

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Check the height of the electrolytic solution in the battery once a month．If the level of
the liquid drops to low．fill it with distilled water until it reaches the high mark．If
there is not enough electrolytic solution，then the diesel engine cannot be started．It is
important to keep the liquid level between the high and low limits．
If the level in the battery is too high，the liquid may flow out and end up on surrounding
parts resulting in corrosion of these parts．
Note：Avoid too much or to little of electr91ytic solution．Check and fill it once-a month．
Note：
If you crank the starter to long，the battery may be drained too much to provide
enough energy for proper engine ignition．Also，when the diesel engine is
operating，let the key retain in the“ON”position．

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2-5 Proper operation of the
generator set
2-5.1 Operating the diesel engine
1．Pre-heat the diesel engine for 3
minutes under no load conditio-
ns．
2．First check the height of the lubri-
cating oil level，if it is low，
refill it．Our diesel engines are
equip-
ed with an alarm system that will
notify you if the oil pressure is
to low．The alarm system will shut
down the engine if the oil pressure
is to low．
3．Do not adjust the speed limit regu-
lation nut or the fuel adjustment
bolt．These bolts have been set by
the factory already，changing them
will affect the properties of the
engine performance．
2-5.2 Checks during engine operation
1．Check to see if there are abnormal
noises．
2．Check to see if the performance is
good or bad．
3．Check the color of the exhaust gases
(whether it is too black or too
white)．If any of these conditions
exist，stop the engine and find the
cause of the problem ．If no
problems are found，please contact
your local dealer or our nearest
company branch．
2-6 Loading
2-6.1 Load conditions
Exert loads in accordance with the speci-
fied parameters．
2-6.2 Output of electricity
1 ．Raise the revolutions per minute
(turn the speed handle to the max
setting)of the generator to get the
maximum power out of the
generator ．If not ，the automatic
voltage regulator device will
excite and doing this for long
periods of time will cause the
capacitor to burn．
2．For the rated speed of the gener-
ator，please refer to Chapter 1，
item 1-l technical specification
and data．
3．Observe the pointer of the volt-
meter ．it should point to 220V
±5％(50Hz)．(For 60Hz set，it will

14
be 240V±5％)．This is the reading of the voltage at the ac socket．
4．When connecting devices to the generator,make sure to connect these devices in
order．Connect the large loads onto the generator first．If everything is functional，
smaller loads can then be added．If the generator shuts off,it may be because the load
being drawn by all the various devices are too high．In this event，decrease the number
of small devices until everything is functional．The total drawn power should not exceed
the maximum output power of the generator ．Please see Table l-1 for technical
specifications of what the generator cain,output．In order to reset the generator after
overdrawn power，let it sit for several minutes．If the indication of the voltameter
is too high or too low，adjust the speed accordingly．If there are problems，stop the
generator immediately and fix the issue．
5．Make sure you are operating your generator in a well-ventilated area．The generator should
never be covered with anything to prevent overheating the generator．
Charging the battery
1．For the electric starter generator,the 12V battery is automatically charged through
the regulator on the generator when it is running．
2．If the generator is not used for long periods of time，the battery should be discon-
nected to avoid energy loss from the battery．
3．Do not connect the negative and positive terminals of the battery together at any
time．Doing so will damage the battery．
4．Do not reverse the polarities when attaching the battery cables to the battery．Doing
so will damage both the battery and the electric starter.
5．When charging the battery，the battery produces flammable gases．Do not smoke，flames，
and sparks get near the battery while it is charging as this may cause afire．To avoid
sparking while connecting the cables to the battery，first，connect the cables to the
battery then to the motor，To disconnect battery cables，first disconnect the motor end
of the cable．
Caution：D0 not start more than two machines at the same time．The
machines should be started one by one．Do not use the floodlight at the
same time when using other devices．

15
2-7 Stopping the generator
1．Take the electrical load off the
generator．
2．Turn generator air switch off.
3．Put the speed handle in the
“RUN”position and let the
engine run for 3 minutes after
unloading．Do not stop the diesel
engine immediately let it warm
down ．Stopping the diesel en-
gine suddenly xnay raise the
temperature of the engine
abnormally and lock the nozzle
and damage the diesel engine.
4．Press down on the brake handle．
5．If equipped with an electric star-
ter ，turn the key to the “Off”
position.
6．Put the fuel handle to the“S”
7．position．
Finally，pull slowly on the recoil
handle until you feel resistance
(this is when the piston is on the
compression stroke ，where the
intake and exhaust valves are
closed)．What this does is prevent
the engine from rusting when not
in use．
Note:
1．If the speed handle is in the“Stop
position and the engine is still
running，turn the fuel switch to
the“OFF”position or loosen the
high pressure oil pipe nut ．The
engine could be stopped more than
one-way other than the speed
handle way．
2．If you cannot stop the engine with
a load on it．then remove the load
first than stop the engine．

16
CHAPTER 3 MAINTENANCE
3-l Maintenance schedules
Keeping your generator well maintained will prolong the life of your generator．Every-
thing needs to be checked including the diesel engine，welder，generator，control cabinet，
and frame．For overhauling procedures，please refer to the instruction manual of the Native
subassembly．If you need these manuals，please call our company and we will send you one．
Before starting the maintenance，make sure the diesel engine is off．
Please refer to the Table 3-1 for the proper maintenance schedule．
Table 3-1．Maintenance schedule for diesel generator set
Interval of
maintenance Item
Everyday
1st month or
after 20 hours
3rd month
or 100 hours
6th month
or 500 hours
Every year
or 1000 hours
Check and fill enough fuel
○
Discharge fuel
○
Check and fill enough engine oil
○
Check whether it leaks oil
○
Check and screw each fastened part
○
●
Screw the bolt of
cylinder head firmly)
Exchange engine oil
○
(1st time)
○
(2nd time late)
Clean filter of engine oil
○
(Exchange)
Exchange air filter element
If operated at dusty region，the period
of maintenance should be shorten)
○
(Exchange)
Clean filter of fuel
○
●
(Exchange)
Check high pressure oil pump
●
Check nozzle
●
Check fuel pipe
●
(If necessary，
exchange it)
Adjust the gaps of air intake and air exhausted gate
●
(1st time)
●
Grind air intake and air exhausted gate
●
Exchange piston ring
●
Check electrolytic solution of accumulator
(each month)
Check electric brush and slide ring
●
Check insulation resistance
The time of stop is over 10 days．○
Note：“●”mark indicates that it needs special wrench,please contact with dealer．

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3-1.1 Changing the engine oil(every 100
hours)
Take the oil cover out．Take off the oil
drain plug when the diesel engine is still
hot．Be careful of hot oil and hot engine
as you may get burned．The bolt is located
at the bottom of the cylinder ．After
draining the oil，put the bolt back and
tighten it ．Then fill with the proper
engine oil tO the proper
level.
3-1.2 Replacing the oil filter
1．Replacing the oil filter every 6
months or 500 hours of operation．
3-l.3 Air filter maintenance schedule
1．Clean air-filter every 6 months or
500 hours of operation．
2．If necessary．exchange it．
3．Do not use detergent to clean air
filter element．
3-1.4 Fuel filter maintenance
1．The fuel filter should be cleaned
often to keep the engine running
at maximum performance．
2．The recommended time period for
cleaning the fuel filter is 6
months or 500 hours of operation.
a．To do this，first drain the fule
from the fuel tank．
b．Loosen the small screws on the
fuel switch and remove the fuel
filter form the port．Use diesel
fuel to clean the fuel filter.
Also．remove the fuel injector
and clean the carbon deposit
around it．The recommended time
period for this is 3 months or
100 hours．
3-1.5 Cylinder head bolt tensions
The cylinder head bolts should be
tightened to specifications please refer
to the diesel engine manual for
pacifications and the special tools
required to do this．
3-1.6 Battery check
Make sure the electrolytic solution
of-the battery is full．The engine uses a
12V battery ．Due to numerous starting
cycles，the electrolytic solution may be
used up．Also，before filling，verify that
the battery is not damaged in any way．Add
distilled water to the battery when
filling．Perform checks on the battery
once a month．
Note：
Never start the engine without the air
filter.This can cause serious damage
to the engine if foreign objects enter
the intake system．Always change the
air filter on time．

18
3-2 Storing for long periods of time
If your generator needs to be stored for long periods of time．the following preparations
should be made．
1．Start the diesel engine for 3 minutes then stop it．
2．When the engine is still hot，change the engine oil with new engine oil of the proper
grade．
3．Pull the rubber plug out of the cylinder head cover and put 2CC of lubricating oil in
it．ten cover the plughole up again．
4．For manual starting generators，press the decompression handle down and pull the recoil
handle 2 or 3 times．This pushes the intake out．(Do not start the engine)
5．For electric started generator，press the decompression handle down and crank the engine
for 2-3 seconds．To do this．put the starter switch in the“Start”position．
(Do not start the diesel engine)
6．Finally，pull the recoil starter until you feel resistance；this is when the piston is
on the compression stroke where the intake and exhaust valves are closed．Having the
intake and exhaust valves closed will prevent rust，as moisture cannot get inside the
combustion chamber．
7．Clean the engine and store it in a dry place．

19
CHAPTER 4 OVERHAULING AND TROUBLESHOOTING
4-1 Overhauling and troubleshooting procedures
Causes of malfunction
Remed
Diesel cannot be started
Not enough fuel
Add enough fuel
The switch of fuel is not at“OPEN”position
Turn the switch of fuel to“OPEN”position
High-pressure pump and nozzle do not inject
fuel or the injected amount is less．
Disassemble the nozzle and adjust it at test
table．
Speed control lever is not at“RUN”position
Tum speed control lever to“RUN”position.
Check level of lubrication oil．
The standard oil amount of lubricating oil
should be between high graduation“H”and low
graduation“L”
It is not quick and powerful to pull
reactive starter.
Start diesel engine in accordance with the
requirements of“start operation procedures”
Nozzle exists dirt．
Clean the nozzle．
Accumulator has not electricity.
Charge the accumulator or exchange it.
Generator cannot general
electricity and has not welding
voltage
Master switch(NFB)is not be switched on
Turn master switch handle to“ON”position．
Carbon brush of generator was worn.
The contact is bad．
Exchange the carbon brush.
The contact of socket is bad．
Adjust the contact feet of socket．
The rated revolution of engine cannot be
reached．
Make it reach to the rated revolution in
accordance with the requirements．
AVR automatic governor is damaged.
Exchange it.
The potentiometer of current regulation
for electric welding is damaged．
Exchange it.
If cannot generate electricity still，please contact with dealer of our company or with
our company directly.
4-2 Questions and Answers
If you do not understand anything or have any questions，please feel free to contact your
local dealer or with our company directly．Below is a list of some information you should
have ready before contacting your local dealer or us．
1．Model of diesel engine generator and engine model number．
2．State of residency
3．Number of hours of operating equipment along with the problem that occurred．
4．A detailed condition and time when the problem occurred，in other words，climate and
atmosphere.