Smith-Root GPP 2.5, GPP 9.0, GPP 5.0, GPP 7.5 User Manual

USER'S GUIDE

GPP MODELS 2.5, 5.0, 7.5 & 9.0

PORTABLE ELECTROFISHERS (W/KOHLER/HONDA/GENERATORS)

07290.14 GPP Shore [winco]

CONTENTS

GPP ELECTROFISHER

Introduction .......................................................................3

Unpacking

Choosing a Location

Fuel Shut-Off Valve

Power Supply Controls

Electrofisher Controls

GPP Display

Operating Procedure

Operating Limits

Maintenance

Basic Troubleshooting

Specifications

Parts List

Fan Kit/Engine Anti-Vibration Mounting

Generator Anti-Vibration Mounting

......................................................................... 4

..................................................... 4

........................................................5

.................................................5

................................................... 6

.......................................................................7

.....................................................8

............................................................. 9

....................................................................10

.................................................. 11

................................................................. 12

........................................................................... 13

............. 14

.......................14

SAFETY

Field Techniques

References

...........................................................26

..................................................................... 27

TROUBLESHOOTING

Procedure 1: 12 AC Voltages (all models) ..... 29

Procedure 2: Continuity & AC Output ........ 30

Procedure 3: Connections, brushes

Procedure 4: Check Rotor Windings

Procedure 5: Stator Windings, Exciters

Procedure 6: Test GPP Control Box

Procedure 7: Test GPP Control Box

Procedure 8: Flashing the Rotor

Procedure 9: Build a Test Load ...............................37

2.5 & 5.0 GPP Generator Stator Wiring ......38

7.5 GPP Generator Stator Wiring

9.0 GPP Generator Stator Wiring

..............31

...........32

......33

............ 34

.............35

.................. 36

................. 39

................40

Contents: Electrofishing Safety & Principles ...... 17

Safety

Electrofishing Safety

Planning For Safety

Backpack Safety

Boat Safety

Do’s & Don’ts

................................................................................. 17

.................................................... 18

...................................................... 19

............................................................19

...................................................................... 19

.................................................................19

ELECTROFISHING

Introduction to Electrofishing ................................. 20

Types of Current

Electrode Design

Items manufactured by companies other than Smith-Root carry the original manufactures warranty. Please contact prod­uct manufacturer for return instructions.

All Smith-Root, Inc. manufactured products are covered by a one year warranty.

........................................................... 22

.......................................................... 23

© 2014 Smith-Root, Inc. Vancouver, WA - USA • 07290 GPP Shore Manual - Rev. 13

www.smith-root.com

1

GPP ELECTROFISHER

USER’S MANUAL

2.5 / 5.0 / 7.5 / 9.0 GPP Combo Package Includes the Following:

Model Qty Description Line Number

1 2.5 GPP Control Box 3418
1 2.5 GPP Generator 4664

2.5 GPP

5.0 GPP

7.5 GPP

9.0 GPP

1 Output Cable 3415
1 Single Foot Switch w/15 ft. Cable & Plug 3309

2 Electrofisher Certification 5465

1 5.0 GPP Control Box 3420
1 5.0 GPP Generator 4666
1 Output Cable 3415
1 Single Foot Switch w/15 ft. Cable & Plug 3309

2 Electrofisher Certification 5465

1 7.5 GPP Control Box 3421
1 7.5 GPP Generator 4667
1 Single Foot Switch w/15 ft. Cable & Plug 3309

1 7.5 GPP Cathode Cable 3416
2 7.5 GPP Anode Cables 2962
2 Electrofisher Certification 5465

1 9.0 GPP Control Box 3867

1 9.0 GPP Generator 4668

1 Single Foot Switch w/15 ft. Cable & Plug 3309

1 9.0 GPP Cathode Cable 6050
2 9.0 GPP Anode Cables 7976
2 Electrofisher Certification 5465

2

2016

GPP ELECTROFISHER

INTRODUCTION

INTRODUCTION

Smith-Root Generator Powered Pulsator (GPP)
electrofishers are unsurpassed in quality and
performance. Our years of experience in
manufacturing electrofishers has helped us to
produce the most complete line of generator
powered electrofishers ever offered. Ranging
from 1.5 to 9kW, Smith-Root manufactures
electrofishers to handle all fresh or brackish
water conductivities.

A complete electrofishing system consists of
an engine, a generator, an electronic pulsator,
an anode, a cathode, cables, and switches.

Our GPP generators are custom-wound
to supply the optimum voltages for
electrofishing, and eliminate bulky and hot
power transformers.

All GPP pulsators are supplied in an aluminum
case with carry handles.

A typical shore hook-up with electrode pole and control box.

www.smith-root.com

3

GPP ELECTROFISHER

USER’S MANUAL

UNPACKING & SET-UP

UNPACKING

Carefully remove the GPP and its
power supply from the shipping
container and examine closely for
shipping damage. If any parts are
missing or the unit is damaged,
notify the transportation company
and immediately file a claim for
the amount of damage. Record
the model and serial number of
your electrofisher in the spaces
provided below:

Model Number:
Serial Number: _______________

When ordering parts, always
include the power supply model
and serial number located on the
unit’s nameplate. This is essential
to ensure the correct replacement
part is shipped to you. Please
keep this manual and refer to
it when making adjustments or
ordering parts. Additional copies
are available for a nominal charge
from your distributor.

_______________

CHOOSING A
LOCATION

In choosing the best location
for your GPP, the following
factors should be taken into
consideration:

FIRE HAZARDS: Locate the
power supply at least 3 feet
(1 meter) away from buildings
or structures. Keep the power
supply away from flammable
trash, rags, lubricants, and
explosives. Do not use the power
supply near any forest, brush,
or grassland unless the exhaust
system is equipped with a spark

arrestor that is effective. Have a
fire extinguisher accessible.

SECURITY: Choose a location
where everyone, especially
children, can be kept away,
to protect them from burns
and electrical shocks. Take
precautions to prevent unqualified
personnel from tampering with or
attempting to operate the power
supply.

SURFACE: Choose a level surface.
If the power supply is tilted, fuel
spillage may result.

MOISTURE: Do not stand the
unit in water or on wet ground.
Protect electrical equipment from
excessive moisture that will cause
deterioration of the insulation and
may result in short circuits.

DIRT: Install the unit in a clean
location. Abrasive materials
such as dust, sand, or lint cause
excessive wear to both engine
parts and generator parts. Grass
and leaves are a fire hazard.

COLD: Engines should be located
where the temperature does not
fall below freezing. Engines start
easiest when they are not subject
to extreme cold.

HEAT: The temperature of the
area where the engine is located
must not exceed 100°F because
the engine is air-cooled. Where
natural ventilation is inadequate
install a fan to boost circulation.

CONFINED SPACE: Restricted air
flow can cause overheating and
damage the engine and generator.
Operation in an enclosed

compartment is also a fire hazard
and is not authorized.

EXHAUST: Whenever an engine
is used indoors, the exhaust
must be vented to the outside.
Exhaust from a gas engine is
extremely poisonous, containing
carbon monoxide, an invisible
odorless gas that can cause
unconsciousness or death.

AUXILIARY WIRING: Use
sufficiently thick insulated wire to
hook up to the auxiliary windings.
The gauge depends on the length
of the wire, the voltage drop,
and the amount and kind of load.
Consult a competent electrician
and national and local codes.

GROUNDING: If grounding is
called for in local codes, or
radio interference necessitates
it, drive a 3/4 or 1 inch pipe into
the ground as close to the unit
as possible. This pipe must
penetrate moist earth. To the pipe
connect a ground clamp and run
a No.10 wire from it to the battery
negative terminal on the control
panel, or to the generator ground
stud. Do not connect to a water
pipe or a ground used by a radio
system. When used in boats,
ensure that generator frame is
grounded to boat hull. This will
prevent a shock in the event of an
electrical failure.

FUEL SHUT-OFF VALVE

The generator has one fuel shut­off valve. Make sure the valve is
open for proper operation. It is
located directly below the choke
lever.

4

2016

4-pin Anode

& Control Plug

4-pin Cathode
& Control Plug

1.5 kVA

Control

4-pin female

Output power

2 pin female

Input power

3-pin female

Type VI-A

Control Input powerOutput power

4-pin Anode

& Control Plug

4-pin Cathode
& Control Plug

1.5 kVA

Control

4-pin female

Output power

2 pin female

Input power

3-pin female

Type VI-A

Control Input powerOutput power

Control

4-pin female

Output power

7 pin female

Input power

7 pin male

2.5 GPP and 5.0 GPP

ControlInput powerOutput power

Cathode Anode

110V
4-pin

9.0 GPP

VVP-15B

Input

AC

Output

& Control

DC

Output

& Control

Xw1”

Xw2”

2.5 - 5.0 GPP

4-pin female

7 pin female

7 pin male

POWER SUPPLY
CONTROLS

GENERATOR: Your GPP
is powered by a specially
manufactured gas-powered
generator. The generator is
wound so that the output
voltages are taken directly from
the generator, eliminating the
need for a transformer or voltage­doubler. The generator has a self­excited revolving field. This rotor
connects directly to the engine
crankshaft with a tapered fit. The
stationary Stator has a separate
excitation winding, and multiple
windings to supply AC power.

12 VAC: terminals on the
generator provide up to 500
watts of 12 volt AC power on
each circuit. This will run 12 volt
lights, or with an external rectifier
will recharge batteries. The 5.0,

7.5 and 9.0 GPP have two output
circuits.

ENGINE: This instruction book
covers mainly the electrofisher
and the generator, but not
the engine. Please read all
instructions in the engine
manufacturer’s manual. The
engine manufacturer has

established an excellent
worldwide service organization.
Engine service is probably
available from an authorized
engine dealer near you: check
your Yellow Pages.

ENGINE GOVERNOR: The engine
must be run at 3600 rpm to
supply the power it was designed
to produce. The governor on
the engine holds the speed as
nearly constant as possible. The
governor is set at the proper
speed in the factory. Do not
adjust the governor without
proper tools.

VOLTAGE VARIATION: All engines
slow down when a load is applied.
When the electrical load on the
generator is increased, the engine
speed drops. This results in a
lower voltage when the generator
is loaded to its full capacity than
when running unloaded.

FREQUENCY VARIATION: The AC
frequency is around 60 cycles per
second. The inevitable variations
in engine speed produce slight
variations in the AC frequency.
This has no noticeable effect on
the operation of motors, lights
and most appliances. However,
clocks and other timing devices
will not keep perfect time when
used on generators.

MODIFICATIONS to the power
supply that are not Smith-Root
authorized may impair the
function and safety of the unit.

GPP ELECTROFISHER

CON-

2.5 - 5.0 GPP

Input power

A

Cathode Anode

B

Cathode Anode

C

Relative positions of input, output, and
control plugs on (A) 2.5-5.0, (B) 7.5 and
(C) 9.0 GPPs

Output power

7.5 GPP

9.0 GPP

110V
4-pin

Control

ControlInput powerOutput power

ControlInput powerOutput power

www.smith-root.com

5

GPP ELECTROFISHER

USER’S MANUAL

1

6

2

7 8

Smith-Root, Inc.

Generator

Powered

Pulsator

3

9

4

5

10

Control Panel

ELECTROFISHER CONTROLS

1 - RANGE SWITCH: Selects the output voltage range between high and low or switches the

output to OFF. Use low range setting for high conductivity water and high range setting
for low conductivity water. DANGER!: The position of this switch should not be

changed when the current is flowing, i.e: when foot switch is engaged.

2 - OUTPUT DISPLAY: Displays all output setting parameters, duration, fault conditions.

3 - EMERGENCY SHUTDOWN SWITCH: Shuts down operation of the GPP and provides a

local override of remote foot switches.

4 - HIGH VOLTAGE INDICATOR: Red indicator lamp shows when voltage is present on

output power terminals.

5 - MODE SWITCH: Selects the type of output pulses, AC, DC or OFF (7.5 only) (

Caution!: The position of this switch should not be changed when current is flowing i.e.
foot switches engaged!).

PERCENT OF POWER CONTROL: Allows the operator to smoothly vary the output voltage and

6 -

pulse width simultaneously, following the positive half of a sine wave

7 -DISPLAY MODE: Switches display readout between Day/Night backlight/contrast modes.

.

8 - TIMER RESET: Resets GPP interval timer to zero.

9 - ANNUNCIATOR VOLUME: Controls the volume of the audio output warning signal.

10 - PULSES PER SECOND: Selects the frequency of pulses in the output wave form.

6

2016

GPP DISPLAY

Peak Average

4vVoltage 2v

0.1

ACurrent 0.1A

0W 0WPower

120

HzFrequency

0

%Duty Cycle

120/170

VRange

1097Time (Sec)

Peak Average

4vVoltage 2v

0.1

ACurrent 0.1A

0W 0WPower

120

HzFrequency

0

%Duty Cycle

120/170

VRange

1097Time (Sec)

Smith-Root, Inc.

Generator

Powered

Pulsator

© 2012GPP 9.0 V1.0.10

Peak Average

4vVoltage 2v

0.1

ACurrent 0.1A

0W 0WPower

120

HzFrequency

0

%Duty Cycle

120/170

VRange

1097Time (Sec)

HIGH CURRENT
WARNING

Switch to Low Setting

Or Reduce Power

Peak Current

51.2

Average

36.7

Smith-Root, Inc.

Generator

Powered

Pulsator

© 2012GPP 9.0 V1.0.10

Peak Average

4vVoltage 2v

0.1

ACurrent 0.1A

0W 0WPower

120

HzFrequency

0

%Duty Cycle

120/170

VRange

1097Time (Sec)

HIGH CURRENT
ERROR

HIGH CURRENT
WARNING

Switch to Low Setting

Or Reduce Power

Output Disabled

Switch to Low Setting

Or Reduce Power

ZERO-CROSS
TIMING ERROR

Contact Smith-Root, Inc.

for Repair

www.smith-root.com
[phone]

14014 NE Salmon Creek Ave

Vancouver, WA 98686

Peak Current

51.2

Average

36.7

Peak Current

51.2

Average

36.7

Peak Average

4vVoltage 2v

0.1

ACurrent 0.1A

0W 0WPower

120

HzFrequency

0

%Duty Cycle

120/170

VRange

1097Time (Sec)

HIGH CURRENT
WARNING

Switch to Low Setting

Or Reduce Power

Peak Current

51.2

Average

36.7

Smith-Root, Inc.

Generator

Powered

Pulsator

GPP ELECTROFISHER

DISPLAY

On power-up, the unit displays
the splash screen with a gray SRI
fish logo.

Smith-Root, Inc.

Generator

Powered

Pulsator

© 2012GPP 9.0 V1.0.10

Startup/splash screen

The splash screen also displays
the GPP model number and
firmware version number.

Peak Average

4vVoltage 2v

ACurrent 0.1A

Typical Status Screen

If no switch is active, the splash

0.1
0W 0WPower

120

%Duty Cycle

0

120/170

1097Time (Sec)

HzFrequency

VRange

screen is replaced, after a few
seconds, with a status screen.

The status screen displays the
numeric value for peak and
average of voltage, current and
power. It also shows the pulse
frequency and, when the unit is
active, the percent duty cycle.

The time in seconds that the
unit has been active is also
displayed on the status screen.
This time is cumulative and the
value is retained through power
cycles. It can be reset to zero
by depressing the “Timer Reset”
button.

The GPP constantly takes voltage
and current readings and displays
these on the status screen. In
addition the GPP compares it’s
current readings with safety
limits specifically for the model
in use. If the current readings
exceed a low limit the GPP will
flash a “Warning” message
on the screen but continue to
operate. If the GPP’s current
readings exceeds a higher limit
the GPP will display a “ERROR”
message on the screen and stop
the output to prevent damage
to the system. Releasing the
Foot switch will remove the error
display and restore the status
display screen.

The status screen has two modes:
A brighter daylight mode and
a contrasting night mode. The
same information is present
in both modes. Pressing the
“Display Dimmer” button will
toggle through the two status
display modes

Display in “Night” mode.

A: Daylight/Night mode selector
B: Timer reset button

www.smith-root.com

FAULT MENUS

The display system also shows
various fault conditions and other
warning dialogs, with possible
solutions.

HIGH CURRENT
WARNING

Switch to Low Setting

Or Reduce Power

Peak Current

51.2

High Current Warning dialog

Average

36.7

HIGH CURRENT
ERROR

Output Disabled

Switch to Low Setting

Or Reduce Power

Peak Current

51.2

High Current Error dialog

Average

36.7

ERROR: SWITCH
ACTIVE AT RESET

Deactivate switch or

contact Smith-Root, Inc.

for Repair

www.smith-root.com
[phone]

Switch Active At Reset dialog

14014 NE Salmon Creek Ave

Vancouver, WA 98686

ZERO-CROSS
TIMING ERROR

Contact Smith-Root, Inc.

for Repair

www.smith-root.com
[phone]

Zero-Cross Timing Error dialog

14014 NE Salmon Creek Ave

Vancouver, WA 98686

7

GPP ELECTROFISHER

USER’S MANUAL

OPERATING PROCEDURE

Before operating the power supply put on safety glasses and ear protectors. Remove wristwatch, rings
and any other jewelry. Do not operate the power supply while smoking. Do not operate while under the
influence of alcohol, drugs or medication.

1. First, check the engine oil level. Use 4-stroke
automotive detergent oil SAE 10W-30. Do not
overfill.

2. Refuel the engine outdoors. Keep away from
any open flame, pilot light, furnace, heater, or
clothes dryer. Stop the engine and allow it to
cool prior to refueling. Never fuel the engine
while it is hot or running to avoid fire, explosion,
bodily injury, or property damage.

3. Use gas with a minimum rating of 85 octane.
Do not use leaded gas because it produces
combustion deposits that may shorten the life
of the exhaust system. Do not mix oil with the
gasoline. Use a clean, properly marked and
approved safety container for storing fuel.

4. Fill the gasoline tank with clean fresh unleaded
gasoline. Do not overfill the tank. Leave half
an inch of the top of the tank to allow space
for expansion. Make sure the fuel cap is tightly
closed.

5. If fuel was spilled, wipe it away carefully. Wait
until the fuel has dried before starting the
engine.

6. Connect the ANODE and CATHODE to the
OUTPUT PWR receptacle(s).

7. Plug the remote control cable (foot switch) into
the 4-pin receptacle.

8. Attach the generator cable/s into the male
plug/s labeled INPUT PWR.

9. Place the anode and cathode in the water, not
touching each other.

10. Fully choke the motor to start. Open the choke
once the engine is running. Do not touch high­voltage spark plug and coil terminals. While
spark voltages are not normally lethal, the
involuntary jerk of the hands caused by electrical
shock may result in injury.

11. On the Electrofisher set the MODE selector
switch to the desired mode. If you are not sure
which mode you desire, start with 120 pps DC.

12. Set the PERCENT OF RANGE to the minimum.

13. Set the RANGE selector switch to LOW .

14. Set EMERGENCY SHUTDOWN switch to ON

15. Set the ENUNCIATOR VOLUME to MIDRANGE.

16. Activate the remote control switch. The high
voltage indicator lamp and audio alarm should
both come on and the display will show voltage
and current readings. Adjust the PERCENT OF
POWER control to achieve optimum response
by the fish. The duty cycle value will follow

the percent of power adjustment and the peak
readings will rise until the pulse encompasses
the highest part of the generator power wave.

The voltage metering circuit on the GPP is a
sensitive, high impedance circuit. When the
GPP is in AC Mode with absolutely no load (the
electrodes are not properly connected or out
of the water), the display may show a Voltage
Warning message. The display will return to
normal when the electrodes are put back into to
the water.

17. Deactivate the REMOTE CONTROL SWITCH
before changing the position of either the
RANGE or MODE switches. Damage to
the range selector switch may result from
switching under load. Experimentation will
be required to learn what mode and voltage
settings are best for various water conditions
and types of fish.

18. If your GPP has been running it hard, run it
for another five minutes under no load before
shutting it down. This allows the electrical
components to cool-down slowly, extending
their life considerably.

19. To avoid burns or fires let the power supply
cool before transporting. When transporting,
turn the fuel valve to the OFF position and keep
the engine horizontal to prevent fuel spillage.
When the power supply is transported over
a long distance or on rough roads, drain the
fuel from the fuel tank. Do not support the
power supply from the top of the frame for any

extended period of time.

OPERATING LIMITS

The GPP is designed to operate within limits that
protect the unit and the generator from serious
damage. When the output current exceeds a low
Warning level for the Range and Frequency Setting
it will start flashing the “High Current Warning”
screen but will continue to operate. If the output
current exceeds a higher Error level of current
output then the GPP display will show the “High
Current Error” screen, the High Voltage Indicator
will go out and the unit will stop operating. Release
the foot-switch, decrease the Voltage and/or Power
setting and depress the foot-switch to resume
output.

8

2016

GPP ELECTROFISHER

OPERATING LIMITS

The average current limits for Warning and Error can be found in the following chart:

2.5 GPP

50-500 V

50-1000V

5.0 GPP

50-500 V

50-1000V

7.5 GPP

120/170 High Current Warning 50.0 30.0 18.0 10.8 6.5

240/340 High Current Warning 25.0 15.0 9.0 5.4 3.3

360/500 High Current Warning 16.6 10.0 6.0 3.6 2.1

720/1000 High Current Warning 8.3 5.0 3.0 1.8 1.1

Frequency 60/120 CPS 60 CPS 30 CPS 15 CPS 7.5 CPS

High Current Warning 5.8 3.4 2.0 1.3 0.8

High Current Error 7.2 4.3 2.6 1.6 1.0

High Current Warning 3.0 1.8 1.0 0.6 0.4

High Current Error 3.7 2.2 1.3 0.8 0.5

Frequency 60/120 CPS 60 CPS 30 CPS 15 CPS 7.5 CPS

High Current Warning 11.3 6.8 4.0 2.5 1.5

High Current Error 14.2 8.5 5.1 3.1 1.9

High Current Warning 6.4 3.8 3.4 1.3 0.8

High Current Error 8.0 4.8 4.3 1.7 1.0

Frequency 60/120 CPS 60 CPS 30 CPS 15 CPS 7.5 CPS

High Current Error 62.5 37.5 22.5 13.5 8.1

High Current Error 31.1 18.8 11.3 6.8 4.1

High Current Error 20.8 12.5 7.5 4.5 2.7

High Current Error 10.4 6.3 3.8 2.3 1.4

9.0 GPP

60/85

120/170

240/340

480/680

Frequency 60/120 CPS 60 CPS 30 CPS 15 CPS 7.5 CPS

High Current Warning 120.0 72.0 43.0 26.0 15.5

High Current Error 150.0 90.0 54.0 32.4 19.5

High Current Warning 60.0 36.0 21.5 13.0 7.8

High Current Error 75.0 45.0 2 7.0 16.2 9.7

High Current Warning 30.0 18.0 11.0 6.5 4.0

High Current Error 37.5 22.5 13.5 8.1 4.9

High Current Warning 15.0 9.0 5.5 3.3 2.0

High Current Error 18.8 11.3 6.8 4.1 2.5

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9

GPP ELECTROFISHER

USER’S MANUAL

MAINTENANCE

Before cleaning or inspecting, make certain all moving parts have stopped. Disconnect the
spark plug wire and keep the wire away from the plug to prevent accidental starting. Do not put
hands, feet, tools or other objects near rotating parts. Always wear eye protection.

1. CHANGE ENGINE OIL after first five hours
of operation. Thereafter, change oil every 25
hours of operation. Use 4-stroke automotive
detergent oil SAE 10W-30 .

2. SERVICE AIR CLEANER. Clean and re-oil the
pre-cleaner at three month intervals, or every
25 hours, whichever occurs first. Remove paper
cartridge yearly, or every 100 hours, whichever
occurs first and clean by tapping gently on a
flat surface. Replace if very dirty. Keep hands
and face away from the carburetor when the
air cleaner is removed. A sudden backfire can
cause serious burns.

3. SPARK PLUG: Clean and reset gap to .030”
every 100 hours of operation.

4. FUEL: Every 250 hours replace the in-line fuel
filter or clean the screen and bowl.

5. REMOVE DUST AND DEBRIS DEPOSITS from
cylinder head and cylinder head shield every
100 to 300 hours of operation.

only with the guards and shields in place and
working correctly. If rotating parts are left
exposed they are hazardous.

7. MUFFLER: Inspect periodically and replace if
necessary. Do not operate the power supply
without a muffler. Inspect spark arrestor screen
every 50 hours and replace if damaged.

8. INSPECT GENERATOR BRUSHES after every
100 hours of operation and replace when worn
to 3/8 inch (1cm) or less. To inspect brushes,
remove brush holder caps, lift brushes out
gently and inspect for wear or breaks in the
brush shunts. Replace brushes in the same
position. Always replace brushes in sets.

9. CLEAN COLLECTOR RINGS at the same time
the brushes are inspected, or after unit has been
out of service for a period of time. Consult your
generator’s OEM manual for proper cleaning
procedures.

6. CHECK GUARDS: Operate the power supply

10

2016

BASIC TROUBLESHOOTING

BASIC TROUBLESHOOTING

PROBLEM SOLUTIONS

GPP ELECTROFISHER

Generator does not generate
electricity

Generator voltage too high*

Generator Voltage too low*

1. Check output voltage of generator at 12 VAC terminals
with lamp or meter.

2. Be sure the load is not too large; reduce if necessary.

3. Check for short circuit in line using an ohmmeter.

4. Test diodes with ohmmeter to see if they are shorted or
open.

5. Check stator winding or field winding for shorts.

6. Flash generator.

1. Refer to engine manufacturer’s manual,

2. Check engine speed with tachometer.

1. Refer to engine manufacturer’s manual,

2. Check engine speed with tachometer.

3. Be sure the load is not too large; reduce if necessary.

4. Check for short circuit in line using an ohmmeter.

5. Test diodes with ohmmeter to see if they are shorted or
open.

Generator overheats

Generator brushes sparking

*Check after generator is sufficiently warmed up: 15 to 20 minutes.

WARNING: Always remove the engine ignition cable before checking or
repairing the power supply to prevent it from accidentally starting.

6. Check stator winding and field winding for shorts,
between windings or to the generator frame.

1. Check output voltage of generator.

2. Be sure the load is not too large; reduce if necessary.

3. Check for short circuit in line using an ohmmeter.

4. Be sure generator is located properly.

Check stator winding or field winding for shorts.

www.smith-root.com

11

GPP ELECTROFISHER

USER’S MANUAL

SPECIFICATIONS

MODEL 2.5 - GPP 5.0 - GPP 7.5 GPP 9.0 - GPP

Conductivity
(microSiemens/
cm)

Rated Output
Power (Watts)

10-1,750 10-5,500 10-11,000 100-25,000

2,500W 5,000W 7,500W 9,000W

Max. Current

12 volt AC/Aux.

Output Pulse
Modes

DC Output Peak
volt

AC Output RMS
volt

Output Pulse
Frequency

Output Current
Metering

High voltage
Output Indicator

Output and
Safety Control

Seconds Timer
LCD Display

Cooling Method

Output
Connectors

8 amp 16 amp 62 amp 150 amp

500 W / 42 amp 2 @ 500 W / 42 amp 2 @ 500 W / 42 amp 2 @ 500 W / 42 amp

Pulsed AC & DC Pulsed AC & DC Pulsed AC & DC Pulsed DC

0-500 V Low

0 - 1000 V High

0-350V Low

0-700V High

7.5, 15, 30, 60 & 120 Hz 7.5, 15, 30, 60& 120 Hz 7.5, 15, 30, 60 & 120 Hz 7.5, 15, 30, 60 & 120 Hz

AC & DC 0-8 amp AC & DC 0-25 amp AC & DC 0-199 amp DC 0-199 amp

Panel Lamp & Audio

Tone

Foot Switch & Panel

Switch

0-999999 0-999999 0-999999 0-999999

Fan Cooled Fan Cooled Fan Cooled Fan Cooled

CPC with

15' Cable

0-500 V Low

0 - 1000 V High

0-350V Low

0-700V High

Panel Lamp & Audio

Tone

Foot Switch & Panel

Switch

CPC with

15' Cable

0V - 170V, 340V, 500V,

1000V

0-700 V N /A

Panel Lamp & Audio

Tone

Foot Switch & Panel

Switch

CPC with

15' Cable

0V - 85V, 170V, 340V,

680V

Panel Lamp & Audio

Tone

Foot Switch & Panel

Switch

POS. CAM CONN.

15' Cable

Engine Size

Generator Weight

Pulsator Weight

Generator
Dimensions

Pulsator
Dimensions

Specification subject to change without notice.
* Note: 12 volt auxiliary power subtracts from Electrofisher power available.

25.5" L x 17.5" W x 18" H 31.5" L x 21.5" W x 20" H 31.5" L x 21.5" W x 20" H 31.5" L x 21.5" W x 20" H

17.5" L x 17.5" W x 13" H 17.5" L x 17.5" W x 13" H 20" L x 15" W x 16" H 20" L x 15" W x 16" H

5 hp 14 hp 14 hp 16 hp

101 lbs. 255 lbs. 265 lbs. 265 lbs.

20 lbs. 20 lbs. 30 lbs. 35 lbs.

12

2016

GPP ELECTROFISHER

To motor shaft

Engine adaptor casting

Fan attaching bolts (4). Use fan installation kit 4540 GPP FIK, shown on next page

Fan

Rotor

Bearing

Stator

Stator bolt (4)

Bearing bracket

Diode module

Stub Shaft
(7.5 & 9.0 only)

Rotor attach bolt

"C" washer

(always replace when

bolt has been loosened)

Adapter casting
mount bolt

Brush housing

Cover

Binding posts

PARTS

PARTS LIST

LINE # DESCRIPTION MODEL

04489 Stator 2.5

04649 Stator 5.0

04491 Stator 7.5

06231 Stator 9.0

04652 Rotor 2.5

04081 Rotor 5.0

02261 Rotor 7.5/9.0

02188 Brush Holder ALL

02227 Brush Holder Cap ALL

02267 Brush & Spring Asmb. ALL

02954 Diode Module ALL

04476 Fan Attach Bolt ALL

LINE # DESCRIPTION MODEL

05594 Rotor Attachment Bolt 2.5/5.0

05312 Rotor Attachment Bolt 7.5/9.0

02260 Fan ALL

08983 Cover ALL

07393 Bearing Bracket ALL

06279 Bearing ALL

00000 Stator Bolt 2.5

00000 Stator Bolt 5.0

00000 Stator Bolt 7.5/9.0

04288 'C' Washer ALL

00000 Engine Adapter ALL

www.smith-root.com

13

GPP ELECTROFISHER

Front view of generator motor

Motor base/Mounting base

D

C

B

A

Drilled Allen screw
with "Loctite" on threads.

Lock washer

Lace wire through holes in pairs of
Allen screws, then twist tight.

FAN

ROTOR

FAN WASHER

USER’S MANUAL

MISC. PARTS

FAN INSTALLATION KIT/ ENGINE ANTI-VIBRATION MOUNTING

Fan Installation Kit

FAN ATTACHMENT

Engine anti-vibration mounting, all models

Rubber Engine Mount Kit
(line#04083)

This fan locking assembly is recommended
for Smith-Root generators.

Line# Description

04540 Fan Installation Kit
02226 Replacement Fan

GENERATOR ANTI-VIBRATION MOUNTING

Item GPP Model Line#

A 2.5 06251
B 5.0, 7.5 & 9.0 06252

All Models

Line #04084

14

2016

Item Description Model

A Mounting bracket ALL
B Rubber mount ALL
C Bolt ALL
D Nut ALL

GPP ELECTROFISHER

SAFETY

ELECTROFISHING SAFETY & PRINCIPLES

Since 1964, the leader in effective, safe, and reliable

products for fisheries conservation.

Knowledgeable field biologists depend upon

Smith-Root equipment.

www.smith-root.com

15

GPP ELECTROFISHER

CONTENTS: ELECTROFISHING SAFETY & PRINCIPLES

SAFETY

SAFETY

Electrofishing Safety ....................................................18

Backpack Safety

Boat Safety

Do’s & Don’ts

ELECTROFISHING PRINCIPLES

Introduction to Electrofishing ................................. 20

Types of Current

Electrode Design

Field Techniques

References

............................................................19

...................................................................... 19

.................................................................19

........................................................... 22

.......................................................... 23

...........................................................26

..................................................................... 27

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17

GPP ELECTROFISHER

USER’S MANUAL

SAFE FISHING

Electrofishing equipment uses
voltages and currents that can be
lethal to humans. The operators
must always keep in mind that
the chance of receiving an
electrical shock is multiplied in or
near water. Using an electrofisher
is like using a firearm: if used
properly and with good judgment
it is perfectly safe; lose respect
for it and you can lose your life!

Electrical equipment used
in a moist field environment is
always subject to deterioration
that could lead to dangerous
electrical shock. Field equipment
is also subjected to vibration
and impact during transporting
and while in operation. Often
equipment shared by different
crews does not receive proper
maintenance or a complete
checkout.

Follow the safety guidelines,
and use good common sense to
handle unforeseen circumstances.

All personnel involved in
electrofishing should be taught
the fundamentals of electricity,
and have an understanding of the
safety requirements.

in electrofishing efficiency
and safety is the training and
experience of the crew. At
least two members of the crew
should be qualified to administer
cardiopulmonary resuscitation.
As oppor tu nities arise, all crew
members should attend a course
in basic life-support training.

ELECTRICAL SHOCK

It is the current that passes
through the human body that
does the damage. The voltage is
relevant, because it is the force
that “pushes” the current through
the body. Experiments show that
20 to 500 Hz AC current is more
dangerous than DC, or higher
frequencies of AC.

electrofishing gear cause death
by one of three means:

• Ventricular Fibrillation

ELECTROFISHING SAFETY

The most important factor

The voltages used by

Ventricular fibrillation is
uncoordinated contraction of
the muscles of the heart. The
heart quivers rather than beats.
Electrical current through the
chest can cause this condition.

Once a person goes into
ventricular fibrillation, the
only way to stop the quivering
is to use a defibrillator that
applies a pulse shock to the
chest to restore heart rhythm.
Cardiopulmonary resuscitation
may help to keep a victim alive
until he can be defibrillated.

• Respiratory Arrest

The respiratory center is at
the base of the skull. Thus,
shocks to the head can cause
the breathing to stop. Artificial
respiration by the mouth-to­mouth method should be used
in this case.

• Asphyxia

Asphyxia is caused by
contraction of the chest
muscles.

18

2016

PLANNING FOR SAFETY

BACKPACK SAFETY

1. Before each operation, check
that the frame emergency
release is in working order
and check that the tilt switch
shuts off power if the unit is
tipped more than 45°

2. Wear hip boots or chest-high
waders, with non-skid soles.

3. Wear polarized sunglasses to
help you detect sub-surface
hazards and obstacles.
Beware of turbid water that
can hide unseen sub-surface
obstacles and sudden drop­offs.

4. Shut off your electrofisher
before entering or leaving a
stream.

5. Do not operate an anode pole
when carrying a backpack
unit weighing more than 20
pounds when in hazardous
conditions.

6. If you get water in boots,
waders, or gloves, stop work
immediately and get dry

clothing

7. Operate slowly and carefully.
Footing in most streams is
poor, and most falls often
occur when operators are
hurrying.

BOAT SAFETY

1. Ground the generator to the
boat hull.

2. Be sure that all the metal
parts on the boat are bonded
to each other electrically.

3. Run all cables through
electrical conduit, or use a
heavy-duty rubber-covered
cord recommended for wet
locations.

4. Make all electrical
connections in water-tight
junction boxes.

5. Each dip netter should have
his own foot switch to control
the output. The switch should
be wired in series with the
emergency off switch of the
boat operator.

GPP ELECTROFISHER

SAFETY

6. When wading with a boat,
even in shallow water, chest
waders should be worn. An
operator may trip, end up in
a kneeling or sitting position
in the water and receive a
shock.

7. All crew members must be
alert. Operators who control
the power switch must be
constantly aware of the
netters in the electrical field.

DO’S & DON’TS

DO’S:

1. Always be sure that all
personnel are clear of the
electrodes before turning on
the power.

2. Know how to administer first
aid treatment for electrical
shock.

3. Wear flotation devices.

4. Have electrical circuits
checked only by qualified
technicians.

5. Disconnect the power supply
when the electrofisher is not
in use.

DON’TS:

1. Don’t electrofish alone!

2. Don’t continue to electrofish
if your boots or gloves get
wet inside.

3. Don’t operate an electrofisher
if you have had any prior
heart ailments.

4. Don’t operate generators
without covers or screens.

5. Don’t operate generators
without a spark arrester.

www.smith-root.com

19

GPP ELECTROFISHER

Electrode

Water

Electrical Field

Voltage Source

Electrode

012345678910

Volts

2V

012345678910

Volts

8V

b. Fish more conductive c. Water more conductive

100mm

012345678910

Volts

5.3V

a. Equal conductivities

53mm

USER’S MANUAL

INTRODUCTION TO ELECTROFISHING

For many years it has been known that fish react to electric current passed through water.
Electricity was first used for fishing in 1863 when a British patent was granted. Major efforts
to apply electricity as a tool in fisheries management did not occur until after 1950. Since
then detailed studies have been made on the physiological effects of electricity on aquatic
organisms.

RESPONSE OF FISH TO ELECTRICITY

To collect fish by electrical means we must create an electrified zone of sufficient amplitude to stun fish.
In the basic electrofishing circuit, shown in Figure 1, a current is passed between submerged electrodes. A
fish between these electrodes forms part of a closed circuit and some current flows through its body.

The effectiveness of the
electrofisher is affected by
nine factors: voltage, electrode
shape, water conductivity, water
temperature, conductivity of the
stream bed, fish’s distance, size,
species, and time in the field.

If these environmental factors
are too far out of line, poor
electrofishing will result. To some
extent, the effects of changes
in water conductivity may be
compensated for by changing the
output voltage.

WATER CONDUCTIVITY

The conductivity of the water
and that of the fish’s flesh are the
factors that affect electrofishing
most.

Figure 1. The basic electrofishing circuit.

The conductivity of water
depends on the quantity of
dissolved salts and minerals in
the water. The conductivity of
potable waters in the United
States ranges from 20 to 2,000
microSiemens/cm. Sufficient
current at realistic power levels
will flow through water in this
range to electrofish successfully.

Figure 2 illustrates the
field patterns caused by the
presence of a fish in water. In
(a) no distortion is caused by
the presence of the fish. In low
conductivity water, (b), the

20

Figure 2. Electric field patterns caused by fish.

distortion of the electric field is
such that the voltage near the
fish is less than it was before the
fish was present. The reverse
is true in (c) where the water

surrounding the fish. In both (b)
and (c) not as much power is
transferred into the fish’s body as
in (a).

conductivity is more than that of
the fish. In this case the distortion
is caused by the current
concentrating in the water

2016

LOW CONDUCTIVITY WATER

Distilled water is a very
good insulator. It has a
conductivity range of 0.5 to 5.0
microSiemens/cm. If a normal
voltage is applied in distilled
water, very little current will
flow. Power flow is too low to be
effective for electrofishing.

The current passing through
a fish decreases as the power
flow decreases. To get the same
response from fish, the current
can be maintained by either
increasing the voltage, or by
keeping the resistance low.

If a higher voltage is used, up
to 1,200 volts may be necessary.
High voltages create three
problems, special electrical
equipment is required, safety is
reduced for the operators, and
conditions are lethal for fish close
to electrodes.

The resistance can be kept
low by increasing the size of the
electrodes. The only limitations to
this are the availability of larger
electrodes, and the weight of
electrode that can be handled by
the operator.

HIGH CONDUCTIVITY WATER

High conductivity is over
2,000 microSiemens/cm. If a
high voltage is applied, most
current will flow easily through
the water and the fish will
hardly be affected. The electric
current follows the path of least
resistance and bypasses the
fish completely. Therefore use
low voltages and high currents.
Currents as high as 60 amps
are common, the limiting factor
being the rating of the power­supply.

GPP ELECTROFISHER

INTRODUCTION TO ELECTROFISHING

Some brackish water and
industrial waste water have
conductivities over 10,000
microSiemens/cm. Here smaller
power-supplies are unable to
deliver enough power to stun
fish. Waters in this range can only
be electrofished effectively with
the larger model GPPs.

The Smith-Root 7.5 GPP
outputs 62 amps through 8
gauge stranded cables. This unit
can stun large fish in the interface
between fresh and salt water. For
example, Striped Bass can be
stunned for taking brood stock.

Theoretically high conductivity
could be dealt with by using
smaller electrodes, but this would
reduce the range and also create
damaging current densities near
the anode.

FISH CONDUCTIVITY

A fish will receive the maximum
shock through its body when
the conductivity of the water is
the same as the conductivity of
the fish’s flesh. Unfortunately,
this is rarely the case. Generally,
fish conductivity is around 115
microsiemens/cm.

FISH SIZE

Among fish of the same species,
the larger fish are more sensitive
to electrical currents. Fish absorb
power as a function of body
surface area. This is important to
remember if you are shocking for
small fish and large fish are also
present. The large fish are going
to receive a much greater shock
than the small fish.

TEMPERATURE

Water conductivity increases
with temperature.

SUBSTRATE

Certain bottom substrates will
conduct electrical current. These
weaken the electric field in the
water, making fish capture less
effective.

ADJUSTING THE VOLTAGE

By adjusting the output voltage,
the effects of the water’s
conductivity on electrofishing
can be reduced.

The current flowing through
the water is directly related to
the voltage applied. The higher
the voltage, the greater the
current will be.

When adjusting the output
voltage the major consideration
is the power being used. This
is especially true for battery
powered electrofishers. Power is
equal to the voltage multiplied
by the current. When figuring the
power for an electrofisher, the
fact that it is usually putting out
pulsed DC must be taken into
consideration. The instantaneous
power during a pulse may be
quite high, but if the electrofisher
is only producing pulses at a 25%
duty cycle, the average power
would be approximately 25% of
the instantaneous power.

www.smith-root.com

21

GPP ELECTROFISHER

straight flexed straight flexed straight

+

0

off on off on off

USER’S MANUAL

TYPES OF CURRENT

ALTERNATING CURRENT

Alternating Current (AC) is an
electrical current in which the
direction of current flow reverses
a number of times per second.

In an AC field, the fish takes
a position transverse to the
electrical field lines and attempts
to face the anode and cathode
successively, in rhythm with
the AC cycle. When the field
strength increases, tetany occurs,
and the fish is stunned. Strong
contractions of the body muscles
make the fish feel rigid.

At high voltages, the larger
fish may be killed, the muscular
contractions being so severe
that vertebrae are fractured and
the brain damaged. Hence AC
electrofishing is only successful
with small fish in low conductivity
water.

DIRECT CURRENT

Direct Current (DC) is the term
given to electrical current that
flows only in one direction. The
current flows from the negative
electrode (cathode) to the
positive electrode (anode).

The reaction of fish to direct
current is quite different from
their reaction to alternating
current. The first reaction of the
fish is to turn toward the anode
and start to swim toward it until
it reaches an electrical field
strong enough to stun it. Being
stunned is called galvanonarcosis.
The severe muscle contractions
caused by AC do not occur, and
the fish recover much faster.

Galvanotaxis: In pulsed DC a fish's body flexes with each pulse.

Voltage across fish

Field Intensity, V/cm

Distance from anode, m

As the fish nears the anode it receives a very high head-to-tail volt­age.

Mortality rate is much lower with
direct current.

PULSED DIRECT CURRENT

Even greater anode attraction
is possible with pulsed direct
current. Pulsed direct current is
made by interrupting steady DC
with an electronically controlled
switch. The switch gives several
on-off pulses per second. The
number of pulses per second
(pulse frequency) and the on
time (pulse width) have different
effects on different species of
fish.

In a pulsed DC field a fish’s
body flexes with each pulse,
and returns to normal between
pulses. This flexing and
straightening accentuates the
involuntary swimming towards
the anode, called galvanotaxis.

Smith-Root Programmable
Output Waveforms give you

6.25

12.5

50 28018 306.25 9.5

704022

120 400

0.00.20.40.60.81.01.2

complete control over your
electrofisher output. This
patented method of synthesizing
waveforms makes it possible to
produce virtually any waveform,
so you can select the one that is
safest for the fish. POW allows
you to create narrow pulses
to achieve the same results as
wide pulses. Narrower pulses
put less power into the water.
This has three benefits: you have
less chance of damage to the
fish, your battery or fuel lasts
longer, and you can work in very
conductive water that overloads
conventional electrofishers.

RESPONSE OF FISH TO DC
FIELDS

22

2016

Current lines Constant voltage lines

0.0 0.2 0.4 0.6 0.8 1.0

1.2

Distance from electrode centers (meters)

volts

1r 2r 3r 4r 5r

200 100 66 50 40

200 100 66 50 40 33

1r 2r 3r 4r 5r

33

10cm

20cm

volts

Distance

Electrode Voltage

Gradient

The field pattern.

GPP ELECTROFISHER

INTRODUCTION TO ELECTROFISHING

and current distribute around
electrofisher electrodes is
complex. Figure 4 shows the
field pattern created by a pair of
closely spaced ring electrodes,
and the voltage gradient
between them. Note that the
current density and voltage
gradient are highest near the
electrodes.

An electric field in water can
be considered to have three
separate areas. The outer
peripheral area is a weak field
that the fish is indifferent to.
The next area, closer to the
electrodes, has a stronger
electrical field, but not enough
to stun the fish. In this area, the
involuntary swimming action
will occur and the fish will
swim towards the anode. The
innermost area has the strongest
electrical field, and the fish within
it are immobilized.

ZONE OF POTENTIAL FISH
INJURY

Fish close to the anode receive
a very high head-to-tail voltage.
Most fish injuries occur within
half a meter from the anode. This

is called the Zone of potential
fish injury. We can minimize the
injury by reducing the time the
electricity is turned on .

DUTY-CYCLE

Duty-cycle is the percent of

on-time. It is a product of the
pulse width and the pulse
frequency. The duty-cycle can
be lowered in three ways: by
reducing the pulse width, by
reducing the pulse frequency, or
by using gated bursts, where the
power is off for a period between
each burst of pulses. Fish close to
an anode with a low duty-cycle
are far less likely to be injured
than with a high duty-cycle.

ELECTRODE DESIGN

The way in which voltage

Figure 4. The variation between
between two electrodes.

www.smith-root.com

Figure 5. Comparison of two sizes of
anode.

The dimensions of the
electrodes are very important
in determining the voltage
distribution around electrofisher
electrodes. Figure 5 compares
a 10cm and a 20cm ring anode
carrying 200 volts in open
water. The cathode dimension is
considered to be infinite. Note
that the 20cm anode reaches
out much further, producing a 33
volt potential at 1.2 meter. But the
10cm anode produces the same
potential at only 0.6 meter from
the electrode.

Figure 6 further illustrates
the effect of electrode diameter.
The voltage is applied head­to-tail to a 20cm long fish. The
applied voltage is 200 volts with
10cm and 20cm diameter ring­electrodes. Note that the 20cm
electrode reaches out farther,
producing 7 volts head-to-tail
between 1.0 and 1.2 meter from
the electrode; as opposed to only

23

GPP ELECTROFISHER

0.0 0.2 0.4 0.6 0.8 1.0

1.2

volts

1r 2r 3r 4r 5r

200 100 66 50 40 33

200 100 66 50 40 33

1r 2r 3r 4r 5r 6r 7r 8r 9r 10r

28 25 22 20 18

100 44 16 10 7

134

4

volts

Distance from electrode centers (meters)

10cm

20cm

35cm

60cm

Electrode diameter

0.0 0.2 0.4 0.6 0.8 1.0 1.2 1.4 1.6 1.8 2.0 2.2

16.63m

2

12.57m

2

10.18m

2

6.16m

2

Distance from electrode centers (meters)

246 44 46 48
Distance from center of anode (meters)

00

100

150

200

250

300

350

400

450

500

550

50

Total voltage

Sufficient gradient zone

Cathode Indentical to anode: 600V, 6.3kW

0.5m2 grid cathode: 350V, 3.7kW

10m2 wire netting cathode: 310V, 3.2kW

anode

cathode

USER’S MANUAL

Figure 6. Comparison of effects of two
sizes of anode.

4 volts for the smaller electrode
at the same distance. Note
also that the voltage the fish
receives closer to the electrode
is less for the larger electrode
(100 volts instead of 144 volts).
Larger electrodes thus offers two
advantages: greater range, and
lower maximum gradient.

One drawback is that a larger
electrode also has greater
circuit loading, and thus draws
more current for the same
voltage (twice as much for the
double size electrode). Thus,
a larger electrode requires a
larger generator. This dictates a
practical upper limit on electrode
size for a given generator and
water conductivity. Except for
this limitation, the larger the
electrode, the better the fishing
effectiveness and the easier it is
on the fish.

Figure 7. Larger anodes increase the
fishing area.

24

Figure 7 shows that larger
electrodes increase the fish
collection area. The shaded areas
have a voltage gradient between

0.12 and 1.2 volts per cm, and are
suitable for electrofishing. The
applied voltage is 300 volts.

ELECTRODE BEHAVIOR

• Larger electrodes have lower

resistance, need more current
at given voltage, reach out
farther, and have lower
maximum voltage gradient.

• Small electrodes pose a hazard

to fish because of high current
density and voltage gradient.

• Electrodes placed farther

apart use less current, but the
savings are not large.

• The resistance of an electrode

varies in direct proportion to
water resistivity.

RING ELECTRODES

• Once spacing exceeds 10

radii, the distance between
electrodes is insignificant.

• The region affected by the

electrode is limited to 5 to 10
radii.

• Electrode resistance is primarily

dependent on electrode radius,
and varies in inverse proportion
to radius.

• For ring electrodes, the cross

section diameter of the ring
material is of little importance.
If the ratio of cross section
diameter to ring radius is held
constant, resistance varies
inversely with ring radius.

CATHODES

In electrofishing it is desirable
to have a high voltage gradient
around the anode, and a low

2016

voltage gradient around the
cathode.

Figure 8 shows variation of
voltage, as a function of the
distance from the fishing anode,
for three types of cathode.

Figure 8. Variation of voltage for three
different kinds of cathode

The required voltage is
reduced by diminishing the
resistance of the cathode
field. This compensates for
the reduced resistance so that
the current does not vary. The
power consumption is directly
proportional to the voltage used.

One advantage of a large
cathode is that the risk of
accidental electrocution is much
reduced. A large cathode has
very low potential with respect
to the soil and the water around
it. The resistance between the
cathode and the water is halved
each time the surface of the
cathode is doubled. For example,
a 100 square foot cathode would
need another 100 square foot
added to pass from 9 to 4.5
ohm. However a cathode larger
than 100 square feet would be
inconvenient to handle for shore­side electrofishing.

Figure 9 compares small and a
large cathodes. With a standard
grid cathode, the anode voltage

GPP ELECTROFISHER

35 99

Resistance ohms

of anode field90509050

between anode and cathode 125 85 99 59

Potential difference volts
between cathode and water 126 185 32 54

324 265 324 302

a. one
anode

Standard 0.5m

2

grid cathode

b. two

anodes anode anodes

Large wire-

netting cathode

326450 450 356

3.6

1.62

5.9

2.38

3.6

1.28

6.0

2.15

between anode and water

c. one d. two

total

Current amps
Power kilowatts

35of cathode

24 46 48

Total potential (volts)

Distance from center of anode (meters)

1.0

1.5

2.0

2.5

3.0

0.5

3.5

Anode

Cathode

Potential gradient (volts/cm)

Potential

Gradient

00

100

200

300

INTRODUCTION TO ELECTROFISHING

Figure 9. Comparison of two sizes of
cathode.

falls distinctly from 324 to 265
volts when using two anodes.
However with a very large wire
netting cathode efficiency falls
only slightly from 324 to 302
volts when using two anodes.

For shore-side operations, the
cathode surface presents the
least resistance when it is divided
into several parts placed several
meters apart. An electrode is
more effective when its form is
least concentrated. For example,
a 3'x12' strip is more effective
than a square of 6'x6'.

Figure 10 illustrates the
variation in both voltage and
gradient between the electrodes.

Whenever possible, the

BOAT CATHODES

Many aluminum electrofishing
boats use the boat hull as
the cathode and the boom
electrodes as the anode. This
is perfectly safe as long as you
never come in contact with
the anode and complete the
electrical circuit. The National
Safety Council in their data sheet
#1-696-85 does not recommend
using the boat hull as the
cathode, but we have yet to
hear of any accidents occurring
because of it.

Figure 11 shows a Smith-Root
tote barge designed for stream
wading operations. Note the
large cathode plate attached

Figure 11. Bottom mounted cathode
plate on SR-6.

diminishing returns is reached.
Doubling the cathode size would
halve the cathode resistance
and give an 8 to 1 ratio between
anode and cathode resistance.
Now 88% of the voltage would
appear at the anode. This is only
an 8% improvement, and is not
worth the additional physical
problems associated with the
larger cathode.

The SR-6 field tested with
two 28cm anodes and a voltage
of 240 volts, showed good
fishing effectiveness in 400
microSiemens/cm conductivity
with a current of 3 to 4 amperes.
In lower conductivities of 40
microSiemens/cm, a current of 1
to 1.5 amp is effective. This data
may serve as a useful bench­mark to judge whether a unit is
operating under conditions such
that fish should be caught. If the
electrical performance is close
to this reference point, and fish
are not being caught, it is safe to
conclude there are few fish in the
area.

Figure 10. Variation of potential and
gradient.

cathode should be placed in
parts of the stream that you do
not wish to fish, or even in parts

completely separated from the
stream itself. The anode should
never be allowed to come close
to where the cathode is located.

to the bottom of the fiberglass
hull. The anode is a pair of ring
electrodes about 28cm (11") in
diameter mounted on fiberglass
poles. With this arrangement,
the resistance of the anode
pair is four times the cathode
resistance. Thus, four times as
much voltage appears in the
anode field as in the cathode
field, and consequently 80% of
the applied voltage appears at
each electrode.

The situation could be
further improved by enlarging
the cathode, but a point of

www.smith-root.com

25

GPP ELECTROFISHER

USER’S MANUAL

FIELD TECHNIQUES

An operator engaged in
electrofishing must wade or float,
depending upon the depth and
swiftness of the water.

WADING

In shallow slow-moving waters
the operators can wade and
probe the anode into likely
fish habitat. Wading upstream
eliminates the effects of turbidity
caused by bottom sediment.
Furthermore, if collections are
for food habitat study, stunned
prey are not swept downstream
and consumed by predators.
Fish that manage to escape are
often captured a short distance
downstream. Closing a stream
with seine nets at each end of the
study area helps prevent the loss
of stunned and frightened fish.

BOATS

Boat electrofishers are used in
lakes and in streams that are too
deep or swift to wade. Boats
have the advantage of being able
to carry large generators and
holding tanks for the stunned
fish. Electrofishing boats typically
have two insulated booms
extending from the bow. From
the end of the booms electrodes
hang into the water. Usually one

boom is used as the anode and
the other as the cathode. The
boat operator guides the boat
while the electrofishing crew
activates the electrofisher when
approaching likely habitat.

NIGHT FISHING

Electrofishing at night with lights
is five to ten times more effective
than daytime fishing, especially
in lakes. In streams the reflection
of the spotlight on the ruffled
surface makes the fish difficult to
see. Boats have flood lights on the
bow to attract the fish and to help
locate stunned fish.

SURPRISE

Collecting can be enhanced
by introducing the element of
surprise through intermittent
fishing. The intensity of the
anode’s peripheral field often
frightens fish, causing them to
bolt and hide. Do not work with
the power on continuously, but
turn it on only in likely habitats.
Fish can be enticed from under
areas of heavy cover or ice by
inserting a portable anode,
turning the power on, and
withdrawing the anode slowly
and smoothly. Fish will follow the
anode, under the influence of

galvanotaxis, into the open where
they can be netted.

CLARITY AND DEPTH

Clarity of the water limits the
ease of capturing fish. The length
of the dip net handles and the
visibility of the fish limit the depth
of effective electrofishing. In
general, waters over ten feet deep
cannot be sampled effectively.
For daytime fishing polarized
sunglasses help in locating
stunned fish.

VEGETATION

Aquatic vegetation grows better
from certain substrates and can
hinder electrofishing by fouling
electrodes and entangling
stunned fish.

WATER VELOCITY

Electrofishing in flowing water is
not as effective as in still water,
since fish are swept away from the
electric field and netting is more
difficult. Also, it is more difficult
to see a fish in fast flowing water,
and operators can loose their
footing. Flows greater than 5 feet
per second usually produce poor
electrofishing efficiencies.

26

2016

GPP ELECTROFISHER

INTRODUCTION TO ELECTROFISHING

ELECTROFISHING REFERENCE & TRAINING MATERIALS

REFERENCES

The following are books, research papers, and other references on various aspects of electrofishing. The
ideas and findings presented in them form the basis for much of the current practice in electrofishing.

1. Bryan R. Cowdell and Richard
A. Valdez, 1994 “Effects of
Pulsed DC Electrofishing on
Adult Roundtail Chub from the
Colorado River in Colorado,”
North American Journal of
Fisheries Management. Vol. 14

2. I. G. Cowx and P. Lamarque,
1990, “Fishing With
Electricity—Applications
in Freshwater Fisheries
Management,” Fishing News
Books, Blackwell Scientific
Publications Ltd. lSBN
0-85238-167-0

3. L. G. Cowx, 1990
“Developments in
Electrofishing,” Fishing News
Books, Blackwell Scientific
Publications Ltd. lSBN
0-85238-166-2

4. N.G. Sharber and S.W.
Carothers, 1988 “Influence
of Electrofishing Pulse
Shape on Spinal Injuries in
Adult Rainbow Trout,” North
American Journal of Fisheries
Management. 8: 117-122

5. Michael A. Bozek and Frank
J. Rahel, 1991 “Comparison
of Streamside Visual Counts
to Electrofishing Estimates
of Colorado River Cutthroat
Trout Fry and Adults,” North
American Journal of Fisheries
Management. Vol. 11

6. D. W. Novotny and G. R.
Priegel, 1971 “A Guideline
for Portable Direct Current
Electrofishing Systems,”
Technical Bulletin No. 5l,
Department of Natural
Resources, Madison, Wisconsin

7. D. E. Snyder and S. A. Johnson,
1991 “Indexed Bibliography
of Electrofishing Literature,”
Larval Fish Laboratory,
Colorado State University, Fort
Collins, Colorado.

8. M. Burridge and G. Goodchild,
1988 “A Bibliography of
Electrofishing,” Ministry of
Natural Resources, Fisheries
Branch, Queen’s Park, Toronto,
Ontario, Canada.

9. Alec G. Maule and Matthew
G. Mesa, 1994 “Efficacy of
Electrofishing to Assess
Plasma Cortisol Concentration
in Juvenile Chinook Salmon
passing Hydroelectric Dams
on the Columbia River,” North
American Journal of Fisheries
Management. Vol. 14

10. N.G. Sharber, S.W. Carothers,
J.P. Sharber, J.C. DeVos,
D.A. House, 1994 “Reducing
Electrofishing-Induced Injury
of Rainbow Trout,” North
American Journal of Fisheries
Management. 14

11. Jeffery C. Barnet and Gary D.
Grossman, 1988 “Effects of
Direct Current Electrofishing
on the Mottled Sculpin,” North
American Journal of Fisheries
Management. Vol. 8

www.smith-root.com

27

GPP ELECTROFISHER

USER’S MANUAL

Contents

Check Generator 12 AC Voltages (all models) ........................ 29

APPENDIX

GPP TROUBLESHOOTING

SHORE MODEL (USING KOHLER CH GENERATOR)

Test for Continuity, High Voltage AC Output

Check connections, brushes, exciter rectifier

Check Rotor Windings

Check Stator Windings

Test GPP Control Box

Test GPP Control Box

Flashing the Rotor

Build a Test Load

2.5 & 5.0 GPP Generator Stator Wiring

7.5 GPP Generator Stator Wiring

9.0 GPP Generator Stator Wiring

..................................................................... 32

.................................................................... 33

....................................................................... 34

....................................................................... 35

............................................................................. 36

.................................................................................37

..................................... 38

................................................. 39

................................................40

.......................... 30

.......................... 31

28

2016

GPP ELECTROFISHER

ADVANCED TROUBLESHOOTING

PROBLEM: NO OUTPUT FROM GPP ELECTROFISHER

PROCEDURE 1: CHECK GENERATOR 12 AC VOLTAGES (ALL MODELS)

GPP Electrofishers have two 500-watt accessory 12 Volt AC windings.
The accessory output terminals are located on the generator end­bell.

• Set the GPP Control Box Voltage range switch to off. Adjust
generator engine speed to 3600 RPM using a vibrating
tachometer which is available at most small engine shops.

• Check the 12 Volts AC on the end bell of generator using an AC
Voltmeter (See Fig. 1.1). They should read approx. 14.5 Volts,
60Hz.

2.5 AND 5.0 GPP ONLY:

• Check the 12 Volts AC on the output connector, pairs: 5 & 6 (See
Fig. 1.2).

Fig. 1.1

V

• If the Voltages are OK, go to procedure 2.

• Flash generator (Follow procedure 8).

• Restart procedure 1.

• If 12 Volts AC are still not present, go to procedure 3.

IMPORTANT!: High voltages are present when

generator is running. Only qualified personnel
should attempt high voltage measurements. We
suggest forming a barricade around the test area
and posting appropriate high voltage warning

12

345

67

5

6

Fig. 1.2

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29

GPP ELECTROFISHER

USER’S MANUAL

PROBLEM: NO OUTPUT FROM GPP ELECTROFISHER (CONT.)

PROCEDURE 2: TEST FOR CONTINUITY AND HIGH VOLTAGE AC OUTPUT

12

345

67

1&2

3&4

Fig. 2.1: 2.5 & 5.0 GPP

1&2

12

67

5&6

3&4

345

SHUT DOWN GENERATOR!

Check all the connector pairs resistance to Generator ground.

2.5 and 5.0 GPP: 1 & 2 / 3 & 4 (See Fig. 2.1)

7.5 GPP: 1 & 2 / 3 & 4 / 5 & 6 (See Fig. 2.2)

9.0 GPP: 1 & 2 / 3 & 4 / 5 & 6 (See Fig. 2.3)
All of the pairs should show open or high resistance (>0.5 Meg­ohm).

• Next, check insulation between winding pairs. If resistance

measures low, the wire or generator insulation is bad.

If low resistance is measured, go to procedure 5.

• With generator running, check for High Voltage on generator

connectors. (See wiring diagrams at the end of this document).

• 2.5 and 5.0 GPP: Check each of the High Voltage terminal pairs on

the output connector for aprx. 360 Volts RMS AC. Pairs: 1 & 2 and 3
& 4 (See Fig. 2.1). 7.5 GPP: Check each of the Voltage terminal pairs
on both of the output connectors for approximately 115 Volts

Fig. 2.2: 7.5 GPP

1&2

12

67

5&6

3&4

345

Fig. 2.3: 9.0 GPP

1&3

1

342

• RMS AC. Pairs: 1 & 2, 3 & 4 and 5 & 6 (See Fig. 2.2).

• 9.0 GPP: Check each of the Voltage terminal pairs on both of the

output connectors for approximately 67 Volts RMS AC. Pairs: 1 & 2,
3 & 4 and 5 & 6 (See Fig. 2.3). Also, check for

• 115 Volts RMS AC on the smaller 2-pin connector.

If the Voltages are LOW or absent go to procedure 3.

If the Voltages are OK, go to procedure 6.

IMPORTANT!: High voltages are present when

generator is running. Only qualified personnel should
attempt high voltage measurements. We suggest
forming a barricade around the test area and posting

30

2016

GPP ELECTROFISHER

ADVANCED TROUBLESHOOTING

PROBLEM: NO OUTPUT FROM GPP ELECTROFISHER (CONT.)

PROCEDURE 3: CHECK CONNECTIONS, BRUSHES, & EXCITER RECTIFIER

• Turn generator off before troubleshooting.

• Open the generator end-bell cover by removing the two large
screws on the housing cover.

• Inspect the wire bundles for chaffing, loose or broken connections.
Repair if needed (See Fig. 3.1).

• Check brushes – replace brushes if
length less than 3/8” ≈(1 cm) (See
Fig. 3.2).

• Clean rotor slip rings with fine non­metalic abrasive pad such as 3-M
“Scotch Brite” (See Fig. 3.3).

Fig. 3.1

• Disconnect wires from rectifier. Check
3-pin rectifier with ohmmeter in diode
testing position. The rectifier should
only conduct one way between AC
and negative pin. Replace if shorted
between pins or if open between pins. (See Fig. 3.4 and inset).

• Correct problems, reassemble and retest using procedure 1 and 2.

If there is still no voltage at connector, continue to procedure 4.

Fig. 3.2

Slip Rings

Fig. 3.3

AC

AC

Rectifier

www.smith-root.com

Fig. 3.4

31

GPP ELECTROFISHER

USER’S MANUAL

PROBLEM: NO OUTPUT FROM GPP ELECTROFISHER (CONT.)

PROCEDURE 4: CHECK ROTOR WINDINGS

Disconnect yellow wires from the brush end cap and the Rectifier.
(See Fig. 4.1).

Measure resistance with ohmmeter between rotor slip rings, through
the Brushes. Brushes are accessible via the brush end-caps. (See Fig.

4.2).

Resistance should read as follows:

• ≈24 ohms – 2.5 GPP

• ≈32 ohms – 5.0 GPP

• ≈36 ohms – 7.5 and 9.0 GPP

Fig. 4.1

Fig. 4.2

If resistance varies significantly from above, take measurements
directly from the slip rings.

Check Rotor Slip Rings to ground (OPEN connection). (See Fig. 4.3).
Replace rotor if measurements are out of specifications.

Go to procedure 5.

Fig. 4.3

32

2016

GPP ELECTROFISHER

ADVANCED TROUBLESHOOTING

Ω

�

PROCEDURE 5: CHECK STATOR WINDING - EXCITER RESISTANCES

• Check wire number tags. Label with tape and pen if missing.

• Cut wires at crimp connectors.

• Strip insulation back 1/4” ≈ (0.5 cm) to expose bare wire.

2

3

4

• Test winding pairs (1 & 2, 3 & 4, 5 & 6, 7 & 8, 9 & 10, 11 & 12,) (See

Fig. 5.1)

• Test yellow exciter wires (See Fig. 5.3) according to table below:

• Test 12 Volt winding pairs (White/White, Black/Black). Each should

1

6

5

3&4 5&6

1&2

7

7&8

10

8

9

9&10 11&12

11

12

GPP Model

Exciter
Wires

66&55

77&55

66&77

≈2.0Ω

≈4.0Ω

≈2.0Ω

5.0, 7.5 & 9.02.5

≈1.7Ω

≈3.4Ω

≈1.7Ω

Ω

2.5

1.2 Ohms

≈

GPP Model

5.0, 7.5 & 9.0

0.4 Ohms

≈

measure ≈0.1 Ohms (See Fig. 5.2).

• Check insulation of all windings to ground (open connection). (See

Fig. 5.4.)

• Replace Stator if out of specifications.

Rotors and end bearings should be replaced as a set. Replace
rotor bearing support bracket if old type. Contact Smith-Root,
Inc. for further information.

EXCITER WINDING RESISTANCES

2.5 GPP:

66-77
55-66

55-77 ≈ 1.5 Ohm

≈ 1 Ohm

Fig. 5.1

Fig. 5.2

66

77

55

5.0 - 7.5 GPP:

9.0 GPP

55-77 ≈ 1 Ohm

55-77 ≈ 1.1 Ohm

SLIP RINGS

2.5 GPP:

5.0, 7.5, & 9.0 GPP:

≈ 3 Ohm

≈ 12 Ohm

STATOR WINDINGS

(1-2 3-4 5-6 etc.) (12V)

2.5

≈ 1.4 Ohm ≈ 0.3 Ohm

5.0 - 7.5

≈ 0.4 Ohm ≈ 0.1 Ohm

9.0

≈ 0.3 Ohm ≈ 0.1 Ohm

9.0 (110V winding) ≈ 1.3 Ohm

www.smith-root.com

Fig. 5.3

Fig. 5.4

33

GPP ELECTROFISHER

as seen from end

USER’S MANUAL

PROBLEM: NO OUTPUT FROM GPP ELECTROFISHER (CONT.)

PROCEDURE 6: TEST GPP CONTROL BOX

Test a single or dual foot switch pedal using an ohmmeter. Carefully
connect the ohmmeter connectors to pins (A & B) on the 4-Pin male
plug. Use care to not allow the ohmmeter connectors to touch when
connecting them to the pins on the 4-Pin male plug. (See Fig.6.1).

The ohmmeter should measure OPEN ohms with the switch off and

ZERO ohms with the switch on. If it does not you may have a broken

A

D

B

C

4-Pin male plug

Fig. 6.1

A B C

wire or a bad switch inside the pedal. If foot switch is inoperative,
return to Smith-Root, Inc. for service. Test dual foot switches with
an ohmmeter using the same method as shown above. Connect the
ohmmeter to pins (A & B) on the 4-Pin connector for switch #1 and to
pins (C & D) for switch #2 (See Fig. 6.1).

• Connect the generator to GPP Control Box.

• Connect the foot switch to GPP Control Box.

• Connect a test load to output cables (see Procedure 9).

Fig. 6.2

Fig. 6.3

Smith-Root, Inc.

Generator

Powered

Pulsator

5 Amp
Fast-Blow
Fuse

WARNING! Keep all personnel clear of the Test Load while the

generator is running!

• Switch mode switch to 120 PPS.

• Turn Percent of Range to 50%.

• Switch the output Voltage selector to low range.

• Switch the “Emergency Shutdown Switch” to OFF position (See
Fig. 6.2, A).

• Start the generator.

• Switch the “Emergency Shutdown Switch” to ON position
(See Fig. 6.2, B).

• Press the foot switches.

• The red light (See Fig. 6.2, C) on the front panel should now be
illuminated and the display should show voltage and current
readings.

• If the red light is not illuminated and the display does not show
readings or is black.

• Turn the generator off.

• Check the Fuse on the GPP main circuit board (See Fig. 6.3).

• Replace fuse if blown. A blown fuse may indicate a short in the
Audio Alarm. Disconnect the Audio Alarm (See Fig. 6.4) before
retesting.

Fig. 6.4

34

Return to start of Procedure 6. If Red light and amp meter

indicates output go to Procedure 7.

2016

ADVANCED TROUBLESHOOTING

PROBLEM: NO OUTPUT FROM GPP ELECTROFISHER (CONT.)

PROCEDURE 7: TEST GPP CONTROL BOX

• Maintain GPP settings from Procedure 6.

GPP ELECTROFISHER

• Start the generator.

• Press foot switches.

• When the Red Light (See Fig. 7.1, A) is illuminated, the display
(See Fig. 7.1, B) should show current and voltage and the seconds
counter (See Fig. 7.2, C) should be counting.

• Adjusting the “Percent of Range” (See Fig. 7.1, D) up to 100% will
increase the amperage shown on the Current Meter.

• Set the “Percent of Range” to 50%.

• Switch the “Mode” switch (See Fig. 7.1, E) from 120 PPS to 60 PPS.
The amperage should drop by half.

CAUTION: Never switch the Voltage Range while the output is ON.

• Retest settings in the high range.

NOTE: If output current is absent, return the control box to Smith-

Root.

D

Fig. 4.1

Fig. 7.1

C

Fig. 7.2

Smith-Root, Inc.

Generator

Powered

Pulsator

Peak Average

4vVoltage 2v

0.1
0W 0WPower

B

ACurrent 0.1A

120

%Duty Cycle

0

120/170

1097Time (Sec)

A

E

HzFrequency

VRange

www.smith-root.com

35

GPP ELECTROFISHER

Facing Stator end with cover removed

USER’S MANUAL

PROCEDURE 8: FLASHING THE ROTOR (FOR BALDOR GENERATORS)

Rotor Flashing is a process of magnetizing the Rotor.
This is necessary for the Generator to produce an
output. This is normally done at the factory and
should not be required unless the Generator has
been disassembled.

Should FLASHING become necessary, stop the
engine and identify the two inner and two outer
brush holders. The right hand brush has a wire that
connects to the three terminal rectifier assembly. The
left brush is connected to the inner windings. (See
Fig.8.1).

Connect the 12 Volt Battery’s positive lead to
the left brush terminal. Next, hold the negative lead
to the right brush terminal for a minimum of ten
seconds. This will re-magnetize the Rotor.

Fig. 8.1

Inside

Brush-holder

Neg
AC

+

12 Volt
Battery

AC

-

Outside

Brush-holder

ROTOR FLASHING (FOR WINCO GENERATORS)

3

1

2

View of Winco generator with end­bell cover removed

To flash the generator assembly, remove the two blue
slide connectors (1 and 2) from bridge (3).
Flash by connecting positive(+) from battery to
positive (+) flag terminal; negative(-) from battery to
AC (Inset, Fig. 8.2).

Remove blue negative (1) and
positive (2) flag connectors from
bridge (3).

Connect the positive lead from
battery to the positive flag
connector.

+

-

Momentarily touch the negative
lead from the battery to the
negativle flag connector - just long
enough to create an arc.

77

55

3 Bridge

1 Neg -

2 Pos +

A Winco generator (left) can be distinguished by its yellow stator housing,
whereas the Baldor has either a black or red stator housing (right).

36

Fig. 8.2

2016

ADVANCED TROUBLESHOOTING

From Anode

From Cathode

Maximum GPP Amperage (2.5 - 5.0)

Maximum GPP Amperage (7.5 - 9.0)

IMPORTANT! Danger! High Voltage is present during test load procedure.
Every effort should be made to keep all personnel away from test load
bucket. It may be necessary to form a barricade around testing area and
post appropriate signs warning of High Voltage.

PROCEDURE 9: BUILD A TEST LOAD

GPP ELECTROFISHER

WARNING: keep all personnel clear of test
load while generator running.

Fig. 9.1

Output
Plug of
GPP

Aluminum Plate

Water

Plastic Bucket

• Construct a test load using a plastic bucket with the
metal handle removed (Fig. 9.1).

• Connect the test load to the GPP Electrofisher as shown
(Fig. 9.2).

• Add tap water to the bucket.

• Set the “Mode Switches” on the GPP Control Box to AC
& 120 PPS/ 60 AC.

• Start the generator.

• Control the GPP output with the “Emergency Shut
Down” switch or Foot switch.

• By turning the “Percent of Range” control up to 100%
and checking the amp meter on the GPP Control Box,
the correct load can be determined. See below:

Model High Low

2.5

5.0

4 Amps

8 Amps

8 Amps

16 Amps

Model DCAC Amperage

7.5 120 V 170 V 62.5 A

31.3 A

20.8 A

10.4 A
150 A60 V 85 V

75 A120 V 170 V

37.5 A240 V 340 V

18.8 A480 V 680 V

9.0

240 V

360 V

720 V

340 V

500 V

1000 V

Ring Lugs
bolted to

Fig. 9.2

Plates

• The amp meter will increase to the maximum as you
turn up the “Percent of Range”.

• The load may be increased by slowly adding table salt
to the water in the bucket.

• If the load is too great for the range selected, the GPP
will operate erratically.

• If the amp meter starts to show a decrease in amps
or is erratic as the “Percent of Range” nears 100%
the generator is over-loading. The water may need to
be changed, or decrease the portions of electrodes
immersed in the water.

www.smith-root.com

37

GPP ELECTROFISHER

Stator end with end cover removed

USER’S MANUAL

2.5 & 5.0 GPP GENERATOR STATOR WIRING

All Wires to GPP Connector14 Ga.

GPP Connector

2

1

5

7

3

4

6

3

2

1

ADVANCED TROUBLESHOOTING

7

6

5

4

55 66

77

8

9

10

11

12

Rectifier assem.

Neg

AC AC

10 Ga.

Stator 

end 

cover

2.5 GPP

Generator Terminals
1 - 2 = 115 Volts @ 441.5 VA
Respectively through
11 - 12 = 115 Volts @ 441.5 VA

14 Ga.

Frame Ground

5.0 GPP

Generator Terminals
1 - 2 = 115 Volts @ 883 VA
Respectively through
11 - 12 = 115 Volts @ 883 VA

(Pairings of Odd # on Left & Even # on Right.)

Output @ Binding Posts
Black wires 12 Volts @ 500 VA
White wires 12 Volts @ 500 VA

38

(Pairings of Odd # on Left & Even #
on Right.)

Output @ Binding Posts
Black wires 12 Volts @ 500 VA
White wires 12 Volts @ 500 VA

2016

ADVANCED TROUBLESHOOTING

7.5 GPP GENERATOR STATOR WIRING

cover

*All Wires to GPP Connectors14 Ga.

GPP ELECTROFISHER

GPP Connector

2

1

5

GPP Connector

5

Rectifier assem.

AC AC

7

2

7

Neg

3

4

6

1

3

4

6

10 Ga.

14 Ga.*

14 Ga.*

14 Ga.

7

6

5

4

3

2

1

55 66

8

9

10

77

Frame Ground

11

12

Stator

end

7.5 GPP

Generator Terminals
1 - 2 = 115 Volts @ 1250 VA
Respectively through
11 - 12 = 115 Volts @ 1250 VA

(Pairings of Odd # on Left & Even # on
Right.)

Output @ Binding Posts
Black wires 12 Volts @ 500 VA
White wires 12 Volts @ 500 VA

Stator end with end cover removed

www.smith-root.com

39

GPP ELECTROFISHER

USER’S MANUAL

9.0 GPP GENERATOR STATOR WIRING

12 Ga*

GPP Connector

2

1

5

GPP Connector

5

3

4

7

6

2

1

3

4

7

6

*All Wires to GPP Connectors 12 ga.

12 Ga*

2

1

5

4

3

6

55 66

ADVANCED TROUBLESHOOTING

7

8

9

10

77

11

12

Rectifier assem.

Neg

AC AC

10 gauge

Stator

end

cover

12 gauge

9.0 GPP

Generator Terminals
1 - 2 = 67 Volts @ 1500 VA
Respectively through
11 - 12 = 67 Volts @ 1500 VA

(Pairings of Odd # on Left & Even # on Right.)

Frame
Ground

Stator end with end cover removed

Output @ Binding Posts
Black wires 12 Volts @ 500 VA
White wires 12 Volts @ 500 VA

4-Pin Connector
110 Volts AC

8988

16 Ga

16 Ga

110 Volts AC

1

23

4

4-Pin
connector

40

2016

S

i

n

c

e

1

9

6

4

[e-mail]
[phone]
Vancouver, WA USA

www.smith-root.com