MQ Power WHISPERWATT Series User manual

To find the latest revision of this publication or
associated parts manual, visit our website at:
www.mqpower.com
OPERATION MANUAL
THIS MANUAL MUST ACCOMPANY THE EQUIPMENT AT ALL TIMES.
WHISPERWATT™ SERIES
MODEL DCA20SPXU4F
60 Hz GENERATOR
(ISUZU 4LE2T DIESEL ENGINE)
INSTRUCTION MANUAL NO. M1844300324C
Revision #6 (09/07/22)

PAGE 2 — DCA20SPXU4F 60 HZ GENERATOR • OPERATION MANUAL — REV. #6 (09/07/22)
PROPOSITION 65 WARNING

DCA20SPXU4F 60 HZ GENERATOR • OPERATION MANUAL — REV. #6 (09/07/22) — PAGE 3
TABLE OF CONTENTS
DCA20SPXU4F
60 Hz Generator
Proposition 65 Warning ........................................... 2
Table of Contents..................................................... 3
Safety Decals .......................................................... 4
Safety Information ............................................. 5–10
Specifications ........................................................ 11
Dimensions............................................................ 12
Installation ....................................................... 14–15
General Information............................................... 16
Major Components ................................................ 17
Engine/Generator Control Panel...................... 18–19
Output Terminal Panel Familiarization ............. 20–22
Load Application.................................................... 23
AC Ammeter Gauge Reading................................ 24
Output Terminal Panel Connections ...................... 25
Inspection/Setup.............................................. 26–30
Generator Start-Up Procedure (Manual) ......... 31–33
Generator Start-Up Procedure (Auto Mode).......... 34
Generator Shutdown Procedures.......................... 35
Maintenance.................................................... 36–46
Troubleshooting (Diagnostics) ............................... 47
Troubleshooting (Generator).................................. 48
Troubleshooting (Engine)................................. 49–50
Generator Wiring Diagram (M1814000603B)........ 51
Engine Wiring Diagram (M1814100723) ............... 52
Controller Wiring Diagram (M1814100803C) ........ 53
Battery Charger Wiring Diagram (Option) ............. 54
Engine Block Heater Wiring Diagram (Option) ...... 55
NOTICE
Specifications are subject to change without notice.

PAGE 4 — DCA20SPXU4F 60 HZ GENERATOR • OPERATION MANUAL — REV. #6 (09/07/22)
SAFETY DECALS
Safety decals are attached to the generator as shown in
Figure 1. Keep these safety decals clean at all times.When
the safety decals become worn or damaged, contact your
nearest dealer or the Multiquip Parts Department.
Figure 1. Safety Decals
M92010000
WARNING
ELECTRIC SHOCK HAZARD
Do not touch internal wiring
or connections while this
machine is operating.
Turn power off before
servicing.
HIGH VOLTAGE
DANGER
M92010040
M90310000
WARNING
HOT COOLANT can cause
severe burns.
Do not remove cap if
radiator is hot.
CAUTION
Maximum capacity of lifting
bail is 3,240 lbs.
M15000140
M90300000
WARNING
MOVING PARTS can cause
severe injury.
DO NOT operate with doors
open.
Stop engine before servicing.
This machine stops and starts automatically
and without notice.
CAUTION
M92010060
WARNING
ELECTRIC SHOCK HAZARD
Do not touch output
terminals while this
machine is operating.
Turn power off before
servicing.
WARNING
ELECTRIC SHOCK HAZARD
Always complete the grounding
path from the ground terminal
on the genset to an external
grounding source.
WARNING
Before connecting this generator to any building’s
electrical system, a licensed electrician must install
an isolation (transfer) switch.
M92010050
Serious injury or death may result without this
transfer switch.
See instruction manual for
details.
M90320000
WARNING
ENGINE EXHAUST can cause
severe injury or death.
Use only in open, well
ventilated areas or
vent exhaust outside.
M90300000
WARNING
MOVING PARTS can cause
severe injury.
DO NOT operate with doors
open.
Stop engine before servicing.
Ensure the “Auto-Off/Reset-Manual” switch is
in the “Off/Reset” position. If it is not, when
the battery cables are connected, the engine
will crank and attempt to start.
CAUTION
M91010040A
This machine stops and starts automatically
and without notice.
CAUTION
M92010060
DANGER
Using a generator indoors CAN KILL YOU IN MINUTES.
120
V
OFF
GAC-2.2H
POWEREDby
HondaEngines
120V
15A
GRPRISEDE
TERRE
ACCIRCUITBREAKER
INTERRUPTEURDE
COURANTPRINCIPAL
NEUTRALBONDEDTOFRAME
NEUTREMISALAMASSEA
LACARCASSEDUMOTEUR
211052
120
V
OFF
GAC-2.2H
POWEREDby
HondaEngines
120V
15A
GRPRISEDE
TERRE
ACCIRCUITBREAKER
INTERRUPTEURDE
COURANTPRINCIPAL
NEUTRALBONDEDTOFRAME
NEUTREMISALAMASSEA
LACARCASSEDUMOTEUR
211052
120
V
OFF
GAC-2.2H
POWEREDby
HondaEngines
120V
15A
GRPRISEDE
TERRE
ACCIRCUITBREAKER
INTERRUPTEURDE
COURANTPRINCIPAL
NEUTRALBONDEDTOFRAME
NEUTREMISALAMASSEA
LACARCASSEDUMOTEUR
211052
NEVER use inside a home
or garage. Even if doors
and windows are open.
ONLY use OUTSIDE and
far away from windows,
doors, and vents.
Generator exhaust contains carbon monoxide. This is
a poison gas you cannot see or smell.
Avoid other generator hazards.
READ MANUAL BEFORE USE.
M90320010
Operation of this equipment may create
sparks that can start fires around dry
vegetation.
A spark arrestor may be required.
The operator should contact local fire
agencies for laws or regulations
relating to fire prevention requirements.
M90420000
WARNING
This unit is designed to contain operating uids only
The environmental containment is not designed to
control uids from an external source. It is the operator’s
responsibility to monitor uid levels at all times.
DO NOT EXCEED THE RECOMMENDED
MAXIMUM CAPACITY
ENVIRONMENTAL
M91110000
SAFETY INSTRUCTIONS
Improper operation of this machine can cause
severe injury or death.
Read the instruction manual carefully
before operation or servicing.
This machine should only be operated by a
person with sufficient knowledge and skill
to ensure safe operation.
High voltage circuits are located inside the
output terminal cover and control panel.
Close the cover and control panel before
operating.
Moving parts and hot surfaces are contained
within the enclosure.
Close all doors and lock them before
operating. M92010030
M92010070
WARNING
ARC FLASH AND SHOCK HAZARD
Appropriate PPE Required
Appropriate Personal Protection
Equipment and Tools Required
when working on this equipment.
M92010000
WARNING
ELECTRIC SHOCK HAZARD
Do not touch internal wiring
or connections while this
machine is operating.
Turn power off before
servicing.
CONTROL PANEL
FRONT VIEW
SIDE VIEW
SIDE VIEW
TOP VIEW
OUTPUT
TERMINAL COVER
M91010000
CAUTION
HOT PARTS can burn skin.
DO NOT touch until the
machine has sufficiently
cooled.
NOTICE
For safety decal part numbers, refer to the associated
parts manual.

DCA20SPXU4F 60 HZ GENERATOR • OPERATION MANUAL — REV. #6 (09/07/22) — PAGE 5
SAFETY INFORMATION
Do not operate or service the generator before reading the
entire manual. Safety precautions should be followed at all
times when operating this generator. Failure to read and
understand the safety messages and operating instructions
could result in injury to yourself and others.
SAFETY MESSAGES
The four safety messages shown below will inform you
about potential hazards that could injure you or others.The
safety messages specifically address the level of exposure
to the operator and are preceded by one of four words:
DANGER, WARNING, CAUTION
or NOTICE.
SAFETY SYMBOLS
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.
NOTICE
Addresses practices not related to personal injury.
Potential hazards associated with the operation of this
generator will be referenced with hazard symbols which
may appear throughout this manual in conjunction with
safety messages.

PAGE 6 — DCA20SPXU4F 60 HZ GENERATOR • OPERATION MANUAL — REV. #6 (09/07/22)
SAFETY INFORMATION
GENERAL SAFETY
CAUTION

NEVER operate this generator without proper protective
clothing, shatterproof glasses, respiratory protection,
hearing protection, steel-toed boots and other protective
devices required by the job or city and state regulations.

NEVER operate this generator when not
feeling well due to fatigue or illness, or when
on medication.

NEVER operate this generator under the influence of
drugs or alcohol.

ALWAYS check the generator for loosened threads or
bolts before starting.

NEVER use the generator for any purpose other than
its intended purposes or applications.
NOTICE

This generator should only be operated by trained and
qualified personnel 18 years of age and older.

Whenever necessary, replace nameplate, operation and
safety decals when they become difficult to read.

Manufacturer does not assume responsibility for any
accident due to equipment modifications. Unauthorized
modification of the generator will void all warranties.

NEVER use accessories or attachments that are not
recommended by MQ Power for this generator. Damage
to the generator and/or injury to the user may result.

ALWAYS know the location of the nearest
fire extinguisher.

ALWAYS know the location of the nearest
first aid kit.
ALWAYS know the location of the nearest phone or keep
a phone on the job site.
Also, know the phone numbers
of the nearest ambulance, doctor, and
fire department.
This information will be invaluable in the case of an
emergency.
GENERATOR SAFETY
DANGER
NEVER operate the generator in an
explosive atmosphere or near combustible
materials. An explosion or fire could result
causing severe bodily harm or even death.
WARNING
NEVER disconnect any emergency or safety devices
.
These devices are intended for operator safety.
Disconnection of these devices can cause
severe injury,
bodily harm or even death
. Disconnection of any of
these devices will void all warranties.
CAUTION
NEVER
lubricate components or attempt service on a
running generator.
NOTICE
ALWAYS
ensure the generator is on level ground
before use.
ALWAYS
keep the generator in proper running condition.

Fix damage to the generator and replace any broken
parts immediately.
ALWAYS
store the generator properly when it is not
being used. The generator should be stored in a clean,
dry location out of the reach of children and unauthorized
personnel.

DCA20SPXU4F 60 HZ GENERATOR • OPERATION MANUAL — REV. #6 (09/07/22) — PAGE 7
SAFETY INFORMATION
ENGINE SAFETY
DANGER

The engine fuel exhaust gases contain poisonous carbon
monoxide. This gas is colorless and odorless, and can
cause death if inhaled.

The engine of this generator
requires an adequate, free
flow of cooling air. NEVER
operate this equipment in
any enclosed or narrow area
where free flow of the air is
restricted. If the air flow is
restricted it will cause injury to people and property and
serious damage to the equipment or engine.

When operating the generator outdoors, DO NOT place
the generator near doors, windows or vents that could
allow carbon monoxide to enter and build up in occupied
spaces.
WARNING

NEVER place hands or fingers inside the engine
compartment when the engine is running.

NEVER operate the engine with heat shields or
guards removed.

Keep fingers, hands, hair and clothing away
from all moving parts to prevent injury.

NEVER operate the generator with the
doors open. Stop the engine before servicing.

DO NOT remove the radiator cap while the
engine is hot. High pressure boiling water
will gush out of the radiator and severely
scald any persons in the general area of
the generator.

DO NOT remove the coolant drain plug while the engine
is hot. Hot coolant will gush out of the coolant tank and
severely scald any persons in the general area of the
generator.

DO NOT drain the engine oil while the engine is hot. Hot
oil will gush out and severely scald any persons near
the generator.
Operation of the generator may create sparks that
can start fires around dry vegetation. A spark arrestor
may be required. The operator should contact local fire
agencies for laws or regulations relating to fire prevention
requirements.
CAUTION
NEVER touch the hot exhaust manifold,
muffler or cylinder. Allow these parts to cool
before servicing the generator.
NOTICE
NEVER
run the engine without an air filter or with a dirty
air filter. Severe engine damage may occur. Service the
air filter frequently to prevent engine malfunction.
NEVER tamper with the factory settings
of the engine or engine governor. Damage
to the engine or generator can result if
operating in speed ranges above the
maximum allowable.

Wet stacking is a common problem with diesel engines
which are operated for extended periods with light or
no load applied. When a diesel engine operates without
sufficient load (less than 30-35% of the rated output),
it will not operate at its optimum temperature. This will
allow unburned fuel to accumulate in the exhaust system,
which can foul the fuel injectors, engine valves and
exhaust system, including turbochargers, and reduce
the operating performance.
In order for a diesel engine to operate at peak efficiency,
it must be able to provide fuel and air in the proper ratio
and at a high enough engine temperature for the engine
to completely burn all of the fuel.
Wet stacking does not usually cause any permanent
damage and can be alleviated if additional load is
applied to relieve the condition. It can reduce the system
performance and increase maintenance. Applying an
increasing load over a period of time until the excess
fuel is burned off and the system capacity is reached
usually can repair the condition. This can take several
hours to burn off the accumulated unburned fuel.

PAGE 8 — DCA20SPXU4F 60 HZ GENERATOR • OPERATION MANUAL — REV. #6 (09/07/22)
SAFETY INFORMATION
FUEL SAFETY
DANGER

NEVER start the engine near spilled fuel or combustible
fluids. Diesel fuel is extremely flammable and its vapors
can cause an explosion if ignited.

ALWAYS refuel in a well-ventilated area, away from
sparks and open flames.

ALWAYS use extreme caution when working with
flammable liquids.

NEVER fill the fuel tank while the engine is
running or hot.

NEVER overfill the fuel tank. Spilled fuel can ignite if it
comes into contact with hot engine parts or sparks from
the ignition system.

Store fuel in appropriate containers, in well-ventilated
areas and away from sparks and flames.

NEVER use fuel as a cleaning agent.

NEVER smoke around or near the
equipment. Fire or explosion could result
from fuel vapors or if fuel is spilled on a
hot engine.
TOWING SAFETY
CAUTION

Check with your local county or state safety
towing regulations, in addition to meeting
Department of Transportation (DOT)
SafetyTowing Regulations,before towing
your generator.

Refer to the MQ Power trailer manual for additional safety
information.

In order to reduce the possibility of an accident
while transporting the generator on public roads,
ALWAYS make sure that the trailer that supports the
generator and the towing vehicle are both mechanically
sound and in good operating condition.

ALWAYS shut down the engine before transporting.
Make sure the hitch and coupling of the towing
vehicle are rated equal to or greater than the trailer
gross vehicle weight rating.
ALWAYS
inspect the hitch and coupling for wear.
NEVER
tow a trailer with defective hitches, couplings,
chains, etc.

Check the tire air pressure on both the towing vehicle and
the trailer.
Inflate trailer tires as indicated on side wall
of tire.
Also check the tire tread wear on both vehicles.
ALWAYS
make sure the trailer is equipped with
safety chains.
ALWAYS properly
attach the trailer’s safety chains to
the towing vehicle.
ALWAYS
make sure the vehicle and trailer directional,
backup, brake, and trailer lights are connected and
working properly.
DOT requirements include the following:
• Connect and test electric brake operation.
• Secure portable power cables in cable tray with
tie wraps.
The maximum speed for highway towing is
55 MPH
unless posted otherwise. Recommended off-road towing
is not to exceed 15 MPH
or less depending on the type
of terrain.

Avoid sudden stops and starts.These can cause skidding
or jackknifing. Smooth, gradual starts and stops will
improve towing.
Avoid sharp turns to prevent rolling.

The trailer should be adjusted to a level position at all
times when towing.

Raise and lock the trailer wheel stand in the upright
position when towing.
Place chock blocks
underneath the wheels to prevent
rolling while parked.
Place support blocks
underneath the trailer’s bumper
to prevent tipping while parked.

Use the trailer’s swivel jack to adjust the trailer height to
a level position while parked.

DCA20SPXU4F 60 HZ GENERATOR • OPERATION MANUAL — REV. #6 (09/07/22) — PAGE 9
SAFETY INFORMATION
ELECTRICAL SAFETY
DANGER

NEVER touch the output terminals
during operation. Contact with the
output terminals during operation can
cause electrocution, electrical shock,
or burn.

The electrical voltage required to
operate the generator can cause severe injury or even
death through physical contact with live circuits.Turn the
generator and all circuit breakers OFF before performing
maintenance on the generator or making contact with
the output terminals.

NEVER insert any objects into the output
receptacles during operation. This is
extremely dangerous.The possibility exists
of electrical shock,electrocution or death.

Backfeed to a utility system can cause
electrocution and/or property damage.
NEVER connect the generator to a
building’s electrical system without
a transfer switch or other approved
device. All installations should be
performed by a licensed electrician in accordance
with all applicable laws and electrical codes. Failure to
do so could result in electrical shock or burn, causing
serious injury or even death.
Power Cord/Cable Safety
DANGER

NEVER let power cords or cables lay in water.

NEVER stand in water while AC power from the
generator is being transferred to a load.

NEVER use damaged or worn cables or cords when
connecting equipment to the generator. Inspect the
insulation for cuts.

NEVER grab or touch a live power
cord or cable with wet hands. The
possibility exists of electrical shock,
electrocution or death.
Make sure power cables are securely connected to the
generator’s output receptacles. Incorrect connections
may cause electrical shock and damage to the generator.
NOTICE
ALWAYS
make certain that the proper power or
extension cord has been selected for the job. See the
Cable Selection Chart in this manual.
Grounding Safety
DANGER
ALWAYS
make sure that electrical circuits are properly
grounded to a suitable earth ground (ground rod) per
the National Electrical Code (NEC) and local codes
before operating the generator.
Severe injury or
death by electrocution
can result from operating an
ungrounded generator.
NEVER use gas piping as an electrical ground.
BATTERY SAFETY
DANGER
DO NOT
drop the battery. There is a possibility that the
battery will explode.
NEVER expose the battery to open flames,
sparks, cigarettes, etc.The battery contains
combustible gases and liquids. If these
gases and liquids come into contact with a
flame or spark, an explosion could occur.
WARNING
ALWAYS wear safety glasses when
handling the battery to avoid eye irritation.
The battery contains acids that can cause
injury to the eyes and skin.
Use well-insulated gloves when picking up the battery.
ALWAYS
keep the battery charged. If the battery is not
charged, combustible gas will build up.
ALWAYS
recharge the battery in a well-ventilated
environment to avoid the risk of a dangerous concentration
of combustible gases.

If the battery liquid (dilute sulfuric acid) comes into
contact with clothing or skin
, rinse skin or clothing
immediately with plenty of water.

PAGE 10 — DCA20SPXU4F 60 HZ GENERATOR • OPERATION MANUAL — REV. #6 (09/07/22)
SAFETY INFORMATION
If the battery liquid (dilute sulfuric acid) comes into
contact with eyes, rinse eyes immediately with plenty
of water and contact the nearest doctor or hospital to
seek medical attention.
CAUTION

ALWAYS disconnect the NEGATIVE battery terminal
before performing service on the generator.

ALWAYS keep battery cables in good working condition.
Repair or replace all worn cables.
ENVIRONMENTAL SAFETY/DECOMMISSIONING
NOTICE
Decommissioning is a controlled process used to safely
retire a piece of equipment that is no longer serviceable.
If the equipment poses an unacceptable and unrepairable
safety risk due to wear or damage or is no longer cost
effective to maintain (beyond life-cycle reliability) and is to
be decommissioned (demolition and dismantlement), be
sure to follow the rules below:

NEVER pour waste or oil directly onto the ground, down
a drain, or into any water source.

Contact your country’s Department of Public
Works or recycling agency in your area and
arrange for proper disposal of any electrical
components, waste or oil associated with
this equipment.

When the life cycle of this equipment is over, remove
the battery and bring it to an appropriate facility for lead
reclamation. Use safety precautions when handling
batteries that contain sulfuric acid.

When the life cycle of this equipment is over, it is
recommended that the frame and all other metal parts
be sent to a recycling center.
Metal recycling involves the collection of metal from
discarded products and its transformation into raw
materials to use in manufacturing a new product.
Recyclers and manufacturers alike promote the process
of recycling metal. Using a metal recycling center
promotes energy cost savings.
EMISSIONS INFORMATION
NOTICE
The diesel engine used in this equipment has been
designed to reduce harmful levels of carbon monoxide
(CO), hydrocarbons (HC), and nitrogen oxides (NOx)
contained in diesel exhaust emissions.
This engine has been certified to meet US EPA evaporative
emissions requirements in the installed configuration.
Attempting to modify or make adjustments to the engine
emission system by unauthorized personnel without proper
training could damage the equipment or create an unsafe
condition.
Additionally, modifying the fuel system may adversely affect
evaporative emissions, resulting in fines or other penalties.
Emission Control Label
The emission control label is an integral part of the emission
system and is strictly controlled by regulations.
The label must remain with the engine for its entire life.
If a replacement emission label is needed, please contact
your authorized engine distributor.

DCA20SPXU4F 60 HZ GENERATOR • OPERATION MANUAL — REV. #6 (09/07/22) — PAGE 11
SPECIFICATIONS
Table 1. Generator Specifications
Model DCA20SPXU4F
Type Revolving field, self-ventilated, protected type synchronous generator
Armature Connection Series
Phase 1
Standby Output 22.0 kW (27.5 kVA)
Prime Output 20 kW (25 kVA)
Voltage (L-L/L-N) 240/120
Power Factor 1.0
Frequency 60 Hz
Speed 1,800 rpm
Aux. AC Power Single Phase, 60 Hz
Aux. Voltage/Output 4.8 kW (2.4 kW × 2)
Dry Weight 1,797 lb. (815 kg)
Wet Weight 2,137 lb. (969 kg)
Table 2. Engine Specifications
Model Isuzu 4LE2T Tier 4 Final Certified
Type 4-Cycle, water-cooled, direct injection, turbocharged and cooled EGR, DOC
No. of Cylinders 4
Bore × Stroke 3.35 in. × 3.78 in. (85 mm × 96 mm)
Displacement 133 cu. in. (2.179 liters)
Rated Output 33.5 hp at 1,800 rpm
Starting Electric
Coolant Capacity 2.3 gal. (8.8 liters)1
Lube Oil Capacity 2.8 gal. (10.5 liters)2
Lube Oil Type API service class CJ-4 or JASO DH-2
Fuel Type #2 Diesel Fuel (Ultra low sulfur diesel fuel only)
Fuel Leak Warning Capacity 12.7 gal. (48 liters)
Fuel Tank Capacity 41.7 gal. (158 liters)
Fuel Consumption 1.62 gal. (6.12 L)/hr. at full load 1.26 gal. (4.77 L)/hr. at 3/4 load
0.94 gal. (3.57 L)/hr. at 1/2 load 0.67 gal. (2.52 L)/hr. at 1/4 load
Exhaust Gas After-Treatment System DOC
Battery 27 (CCA 0° F 525 A) × 1
1 Includes engine, radiator, reserve tank, and hoses
2 Includes filters and filter hoses

PAGE 12 — DCA20SPXU4F 60 HZ GENERATOR • OPERATION MANUAL — REV. #6 (09/07/22)
DIMENSIONS
3,240 lb.
(1,470 kg)
Figure 2. Dimensions
Table 3. Dimensions
Reference
Letter Dimension in. (mm) Reference Letter Dimension in. (mm)
A 22.91 (582) E 22.36 (568)
B 21.73 (552) F 71.65 (1,820)
C 22.36 (568) G 49.61 (1,260)
D 26.38 (670) H 31.10 (790)

DCA20SPXU4F 60 HZ GENERATOR • OPERATION MANUAL — REV. #6 (09/07/22) — PAGE 13
NOTES

PAGE 14 — DCA20SPXU4F 60 HZ GENERATOR • OPERATION MANUAL — REV. #6 (09/07/22)
INSTALLATION
Figure 3. Typical Generator Grounding Application
GENERATOR
GROUND LUG
GROUND CABLE
GROUND ROD
REFERENCE
NEC 250
Connecting The Ground
Consult with local electrical and safety codes for proper
connection based on condition of use. Refer to the
Conductor Grounding Table, Article 250 of the NEC
handbook.
NOTICE
Trailer-mounted generators are the sole responsibility
of MQ Power.
GENERATOR GROUNDING
ALWAYS refer to Article 250 (Grounding and Bonding) of
the National Electrical Code (NEC).
EXAMPLE of how to ground the unit (Figure 3) if the
condition of use requires such a device:
NOTICE
ALWAYS check with state, province, district, and
municipalities for electrical grounding requirements
before using the generator.

DCA20SPXU4F 60 HZ GENERATOR • OPERATION MANUAL — REV. #6 (09/07/22) — PAGE 15
INSTALLATION
OUTDOOR INSTALLATION
Install the generator in an area that is free of debris,
bystanders, and overhead obstructions. Make sure the
generator is on secure, level ground so that it cannot slide
or shift around. Also, install the generator in a manner so
that the exhaust will not be discharged in the direction of
nearby homes.
The installation site must be relatively free from moisture
and dust. All electrical equipment should be protected
from excessive moisture. Failure to do so will result in
deterioration of the insulation and will result in short circuits
and grounding.
Foreign materials such as dust, sand, lint, and abrasive
materials have a tendency to cause excessive wear to
engine and alternator parts.
INDOOR INSTALLATION
Exhaust gases from diesel engines are extremely
poisonous. Whenever an engine is installed indoors the
exhaust fumes must be vented to the outside. The engine
should be installed at least two feet from any outside wall.
Using an exhaust pipe which is too long or too small can
cause excessive back pressure which will cause the engine
to heat excessively and possibly burn the valves.
CAUTION
Pay close attention to ventilation when operating the
generator inside tunnels and caves.The engine exhaust
contains noxious elements. Engine exhaust must be
routed to a ventilated area.
MOUNTING
The generator must be mounted on a solid foundation
(such as concrete) and set firmly on the foundation to
isolate vibration of the generator when it is running. The
generator must be mounted at least 6 inches above the floor
or grade level as referenced in the National Fire Protection
Association handbook (NFPA 110, Chapter 7, Section 7.4).
DO NOT remove the metal skids on the bottom of the
generator. They are to resist damage to the bottom of the
generator and to maintain alignment.

PAGE 16 — DCA20SPXU4F 60 HZ GENERATOR • OPERATION MANUAL — REV. #6 (09/07/22)
GENERATOR
This generator (Figure 4) is designed as a high-quality,
portable (requires a trailer for transport) power source for
telecom sites, lighting facilities, power tools, submersible
pumps and other industrial and construction machinery.
OPERATING PANEL
The “Operating Panel” is provided with the following:
ECU-754 Controller with Gauge Unit Assembly
• Oil Pressure Gauge
• Water Temperature Gauge
• Charging Voltmeter
• Fuel Gauge
• Tachometer
Panel Light/Panel Light Switch
Pre Heat Lamp
Warning Lamp (Diagnostic)
Hour Meter
Engine Speed Switch
Auto Start/Stop Switch
Fuel Leak Detected Alarm Lamp
CONTROL PANEL
The “Control Panel” is provided with the following:
Frequency Meter (Hz)
AC Ammeter (Amps)
AC Voltmeter (Volts)
Ammeter Change-Over Switch
Voltage Regulator
3-Pole, 90-Amp Main Circuit Breaker
“Control Box” (located behind Control Panel)
• Automatic Voltage Regulator
• Current Transformer
• Starter Relay
OUTPUT TERMINAL PANEL
The “Output Terminal Panel” is provided with the following:
Two 120/240V output receptacles (CS-6369), 50A
Two auxiliary circuit breakers, 50A
Two 120V output receptacles (GFCI), 20A
Two GFCI circuit breakers, 20A
Four output terminal lugs (1Ø power)
Battery Charger (Option)
Engine Block Heater (Option)
Low Coolant Switch (Option)
Cam-Lok Connectors (Option)
OPEN-DELTA EXCITATION SYSTEM
Each generator is equipped with a state-of-the-art,
open-delta excitation system. The open-delta system
consists of an electrically independent winding wound
among stationary windings of the AC output section.
There are four connections of the open delta—A, B, C,
and D. During steady state loads, the power from the
voltage regulator is supplied from the parallel connections
of A to B, A to D, and C to D. These three phases of the
voltage input to the voltage regulator are then rectified and
are the excitation current for the exciter section.
When a heavy load such as a motor starting or a short
circuit occurs, the automatic voltage regulator (AVR)
switches the configuration of the open delta to the series
connection of B to C. This has the effect of adding the
voltages of each phase to provide higher excitation to the
exciter section and thus better voltage response during the
application of heavy loads.
The connections of the AVR to the AC output windings are
for sensing only. No power is required from these windings.
The open-delta design provides virtually unlimited excitation
current, offering maximum motor-starting capabilities. The
excitation does not have a ‘fixed ceiling’ and responds
according the demands of the required load.
ENGINE
This generator is powered by a 4-cylinder, 4-cycle,
water-cooled, direct injection, turbocharged, EGR, DOC,
Isuzu 4LE2T diesel engine. This engine is designed to
meet every performance requirement for the generator.
Reference Table 2 for engine specifications.
In keeping with MQ Power’s policy of constantly improving
its products, the specifications quoted herein are subject
to change without prior notice.
MICROPROCESSOR CONTROL SYSTEM
A microprocessor controls the RPM of the engine. When the
engine demand increases or decreases, the microprocessor
system regulates the frequency variation to ± 0.25%.
EXTENSION CABLES
When electric power is to be provided to various tools or
loads at some distance from the generator, extension cords
are normally used. Cables should be sized to allow for
distance in length and amperage so that the voltage drop
between the generator and point of use (load) is held to
a minimum. Use the cable selection chart (Table 11) as a
guide for selecting the proper extension cable size.
GENERAL INFORMATION

DCA20SPXU4F 60 HZ GENERATOR • OPERATION MANUAL — REV. #6 (09/07/22) — PAGE 17
MAJOR COMPONENTS
2
3
4
6
5
8
1
7
9 10 11
12
Figure 4. Major Components
Table 4. Generator Major Components
ITEM NO. DESCRIPTION
1 Muffler Assembly
2 Output Terminal Panel Assembly
3Emergency Stop Switch Assembly
S/N 8720596 and Above
4 Generator Assembly
5 Engine Assembly
6 Coolant Drain Assembly
7Fuel Tank Assembly
8 Oil Drain Assembly
9 Main Circuit Breaker Assembly
10 Generator Control Panel Assembly
11 Gauge Unit Assembly
12 Battery Assembly

PAGE 18 — DCA20SPXU4F 60 HZ GENERATOR • OPERATION MANUAL — REV. #6 (09/07/22)
The definitions below describe the controls and functions
of the Engine/Generator Control Panel (Figure 5).
1. ECU Controller with Gauge Unit Assembly — This
assembly houses the various engine monitoring
gauges. These gauges indicate: oil pressure, water
temperature, charging voltmeter, fuel level, and engine
speed RPM (tachometer).
A. Oil Pressure Gauge — During normal operation
this gauge should read approximately 50 psi
(345 kPa). When starting the generator the oil
pressure may read a little higher, but after the
engine warms up the oil pressure should return
to the correct pressure range.
B. Water Temperature Gauge — During normal
operation this gauge should read approximately
180°F (82°C).
C. Charging Voltmeter Gauge — During normal
operation this gauge indicate greater than 14 VDC.
D. Fuel Gauge — Indicates the amount of diesel
fuel available.
E. Tachometer — Indicates engine speed in RPM
for 60 Hz operation. This meter should indicate
1,800 RPM when the rated load is applied.
Figure 5. Engine/Generator Control Panel
2
3
4
5
6
9
7
8
10
11 12
15
14
13
LowOilPressure
HighTemp
OverCrank
OverSpeed
Engine
Started
Low
Fuel
ECU Integrated
GaugeControl
R
F
n/min
D
D
n/min
LowOilPressure
HighTemp
OverCrank
OverSpeed
Engine
Started
Low
Fuel
ECU Integrated
GaugeControl
R
n/min
DD
D
n/min
F. Warning LEDs
• Low Oil Pressure LED — This LED will light
when the engine oil pressure drops to 14.2 psi
(98 kPa). This condition will cause the engine
to shut down.
• High Temperature LED — This LED will light
when the coolant temperature has reached
212°F (100°C). This condition will cause the
engine to shut down.
• Over Crank LED — This LED will light when
the engine has attempted to start 3 times and
failed. The interval between the 3 start cycles
is approximately 10 seconds.
• Over Speed LED — This LED will light when
the engine is running at an unsafe speed. This
condition will cause the engine to shut down.
• Low Fuel LED — This LED will light when the
fuel level falls below 20%. Shutdown will activate
at 5%.
• Engine Started LED — This LED will light when
the engine has started and is operating correctly.
2. Panel Light Switch — When activated will turn on the
control panel light.
3. Panel Light — For operation at night, the panel light
illuminates the control panel for ease of reading meters
and gauges. Make sure the panel light switch is in the
OFF position when the light is not in use.
ENGINE/GENERATOR CONTROL PANEL

DCA20SPXU4F 60 HZ GENERATOR • OPERATION MANUAL — REV. #6 (09/07/22) — PAGE 19
ENGINE/GENERATOR CONTROL PANEL
4. Frequency Meter — Indicates the output frequency
in hertz (Hz). Normally 60 Hz.
5. AC Ammeter — Indicates the amount of current the
load is drawing from the generator per leg selected by
the ammeter phase-selector switch.
6. AC Voltmeter — Indicates the output voltage present
at the U,O, and V Output Terminal Lugs.
7. Fuel Leak Detected Alarm Lamp — This lamp when
ON indicates that fluids in the containment area have
reached a high level.
8. Warning Lamp — This lamp turns ON when an engine
fault/failure has occured. Reference troubleshooting
diagnostic section in this manual.
9. Hour Meter — Indicates the operational hours of the
generator.
10. Pre-Heat Lamp — When the Auto Start/Stop Switch is
placed in the manual position, this lamp will illuminate to
indicate preheating of the engine glow plugs. When the
lamp turns off, this indicates that the preheat cycle is
complete and the engine can be started.
11. Auto Start/Stop Switch — This switch selects either
manual or automatic operation. Center position is OFF
(reset).
12. Engine Speed Switch — This switch controls the
speed of the engine, low or high.
13. Voltage Regulator Control Knob — Allows ± 5%
manual adjustment of the generator’s output voltage.
14. Ammeter Change-Over Switch — This switch allows
the AC ammeter to indicate the current flowing to the load
connected to any phase of the output terminals, or to be
switched off. This switch does not affect the generator
output in any fashion, it is for current reading only.
15. Main Circuit Breaker — This three-pole, 90-amp main
circuit breaker is provided to protect the U,O, and V
output terminal lugs from overload.

PAGE 20 — DCA20SPXU4F 60 HZ GENERATOR • OPERATION MANUAL — REV. #6 (09/07/22)
OUTPUT TERMINAL PANEL FAMILIARIZATION
OUTPUT TERMINAL PANEL
The Output Terminal Panel (Figure 6) shown below is
located on the right-hand side (left from control panel) of
the generator. Lift up on the cover to gain access to
receptacles and terminal lugs.
NOTICE
Terminal O is neutral bonded to the ground from the
factory.
OUTPUT TERMINAL FAMILIARIZATION
The “Output Terminal Panel” (Figure 6) is provided with
the following:
Two 120/240 output receptacles @ 50 amps
Two Aux. Circuit Breakers @ 50 amps
Two 120V GFCI receptacles @ 20 amp
Two GFCI Circuit Breakers @ 20 amps
Four Output Terminal Lugs (U, O, V, and Ground)
AUX. POWER RECEPTACLES
120/240V, 50 AMPS
120 VAC, 20 AMP
GFCI RECEPTACLES
Y
X
W
CS-6369
TWIST-LOCK
CIRCUIT BREAKERS
FOR GFCI RECEPTACLES
RECEPTACLE
AND
CIRCUIT BREAKER
PANEL
HARD WIRE
HOOKUP PANEL
UOV
BLACK RED
WHITE GREEN
SINGLE PHASE
240 -120 VAC
OUTPUT TERMINALS
NEUTRAL
TERMINAL
GROUND
TERMINAL
CIRCUIT BREAKERS
FOR CS-6369 TWIST
LOCK RECEPTACLES
20
Figure 6. Output Terminal Panel