Northern Lights OGSC300 User manual

OGSC300
AutoStartGeneratorSetController
OPERATOR’SMANUAL
Marine Generators | Marine Diesel Engines | Land-Based Generators

Northern Lights
4420 14th Avenue N.W.
Seattle, WA 98107
Tel: [phone]
Fax: [phone]
Copyright ©2012 Northern Lights, Inc.
All rights reserved. Northern Lights™, and
the Northern Lights logo are trademarks of
Northern Lights, Inc.
Printed in U.S.A.
PART NO.: OGSC300 08/12

1 - GSC300 Product Number Itentification...................................................1
2 - Wiring Installation Guidelines...............................................................1-2
2-1 - Wiring Guidelines ...............................................................................3
2-2 - 12/24 VDC System Operation ............................................................4
2-3 - Terminal Description...........................................................................5
2-4 - Wiring Connection Diagram.................................................................
6
2-5 - Back Panel Layout............................................................................... 6
3 - Controller Operation.................................................................................7
3-1 -
Controller Overview .................................................................................7
3-2 - LED Layout.........................................................................................8
3-3 - LED Indicators....................................................................................8
4 - Programming The GSC300 Settings........................................................9
4-1 - Numbering of LED’s and Location of Mode Switch ..........................10
4-2 - Sample Screen from PC Interface.....................................................11
5 - Troubleshooting Guidelines................................................................... 12
6 -
Technical Notes/Frequently Asked Questions ................................................ 13
Proprietary Information
This publication is the sole property of Northern Lights, Inc.
It may not be reproduced in whole or part without the expressed written permission of Northern Lights, Inc.
© Northern Lights, Inc. 2011. All rights reserved. Litho U.S.A. Publication number: OGSC300 8/12
I
Please Read Manual Before Installing Unit
Table of Contents..........................................................................................................................................I
Warranty Policy ...........................................................................................................................................II
GSC300 Specifications..........................................................................................................................III- IV
Table of Contents
OPERATORS MANUAL
for GSC300
Auto Start Generator Set Controller

OGSC300 08/12
4II
GSC300 Warranty Policy
LIMITED WARRANTY POLICY: The Northern Lights GSC300 engine controller is warranted by the original
manufacturer, DynaGen Technologies Inc. DynaGen Technologies Inc. hereafter known as the Seller warrants
articles sold hereunder to be free from defects in material and workmanship. These express warranties are the
sole warranties of the Seller and any other warranties, expressed, implied in law, or implied in fact, are
hereby specifically excluded. The Seller’s sole obligation under its warranty shall be, at its option, to either
issue a credit, or repair or replace any article or part thereof, which is proved to be defective. Any adjustment
of credits will be based upon original billing prices. All warranties shall expire 5 years from date of shipment by
the seller, unless otherwise specified in other written communications from the Seller. Any replacement prod-
uct provided to the Buyer shall be subject to the original warranty period, which will expire 5 years from the
date of shipment of the original article. Notice of claimed breach of warranty must be given within the appli-
cable period. No allowances shall be made to the Buyer for any transportation, duties, brokerage fees, labor
costs, or parts adjustments or repairs, or any other work, unless said charges are authorized in writing, in
advance, by the Seller. The Seller shall, in no event, be liable for special or consequential damages or for loss
of profit. The warranty shall not extend to any articles or parts thereof which have been installed, used, or ser-
viced, other than in conformity with the Seller’s application specifications, manuals, bulletins, or instructions,
or, if none, shall have been subjected to improper installation, misuse, or neglect. The warranties shall not
apply to any materials or parts thereof, furnished by the Buyer, or acquired from others at the Buyer’s request
and/or to the Buyer’s specifications or designs. The foregoing limitations on the Seller’s liability in the event of
breach of warranty shall also be the absolute limit of the Seller’s liability in the event of the Seller’s negligence
in manufacture, installation, service, or otherwise, with regard to the articles covered hereby, and upon the
expiration of the stated warranty period, all such liabilities shall terminate.
RETURNS: If any article is claimed to be defective in material or workmanship, the Seller, upon notice
promptly given, will issue a written return material authorization (RMA) with shipping instructions for return to
the Seller. All returns must be accompanied by an RMA number or shipments will not be accepted by the
Seller. Articles which are returned as defective, but are found to meet the specifications agreed upon, will be
subject to a re-testing charge. At the discretion of the Seller, unused and undamaged Standard Products may,
under certain circumstances, be accepted back for credit or exchange. A restocking charge of 15% will apply.
Unused custom designed products will not be accepted back for credit or exchange.
For questions or comments regarding this product, contact:
Northern Lights
Phone [phone]
Fax [phone]
Email: [email protected]
Web: www.northern-lights.com

OGSC300 08/12
5
Operating Voltage: 7 to 30 VDC continuous
Zero volts operation for 100mS (assumes supply was 12 VDC before initiating
starting)
Operating Tempera-
ture: -400C to +850C (LCD Display operates from to -160C to 700C)
Physical Dimen-
sions: 4.5” (H) x 5.5” (W) x 1.25” (D)
Actual Unit Weight: 0.458 lbs
Enclosure: High Impact Resistant, Injection Molded Plastic Enclosure
Front Panel Indica-
tions -High intensity LED’s with regulated brightness
LED Display -
Ultra-bright, Backlight LCD display with optimum viewing angle of 0 - 250 from perpen-
dicular
-Display Size (mm) 8 (W) x 32 (H) x 12.8 (D) x (2 line x 8 character display)
Adjustments
Warm-up: 0 - 200 Seconds (After Oil Bypass Feature)
Cool-Down: 0 - 812 Seconds
Crank Disconnect: 12 - 140 Hz
Overspeed: 40 - 200 Hz
Crank Rest: 4 - 32 Seconds
Delay on Start: 0 - 59 Seconds
Crank Tries: 1 - 10
Oil Bypass: 10 - 55 Seconds
Low Battery Indica-
tion: 7 - 35 VDC
Timer Adjustments
Glow Plug/Preheat: 0 - 255 Seconds
Energize To Stop
(ETS):
Energizes for 15 Seconds on failures, or energizes until 5 Seconds after engine speed
goes to zero upon removing power from Start/Stop terminal or removing the unit from
manual mode using the front panel buttons.
III
GSC300 Specifications

OGSC300 08/12
6
Inputs
Speed Sensing: -Generator Output Speed Sensing
Maximum Input Voltage: 300VAC RMS
Minimum Input Voltage: 0.7VAC RMS Generator Output Sensing
-60Hz Rejection Filter Included
-Loss of Speed Signal Included
Sender/Failure
Inputs: Oil Pressure Coolant Temperature
Fuel Level / Auxiliary
Input
-Accepts standard industry low impedance (0-500
ohm) sender inputs (VDO, Stewart-Warner, Datcon,
Murphy, etc.)
-Custom senders can be accommodated for in PC pro-
gramming
-Programmable for either switch or sender configu-
ration
-Adjustable failure set-points
Protection -Three on-board replaceable 40A fuses protect Fuel, Crank, and Timer Out-
puts
-Reverse polarity protected
-Short circuit & overload protection on annunciation outputs
-Inputs are electrostatic discharge protected
-Maximum power supply surge before damage: 1500V for 250us
Outputs -All outputs switched to +battery (sourcing)
-Fuel, Crank, and Timer
Outputs:
40A each, using standard 40A automotive relays
-Annunciation Outputs: 300mA individually, 350mA combined
Connections -Removable terminal block for annunciation outputs and low power connec-
tions
-0.25” spade terminals for high current and Main power inputs
Programming -Windows based software interface utilizing the parallel port of your PC
-Option of programming through 3-button interface (limited parameter adjustment) on
the front panel or the PC Interface that has full parameter programming ability.
-Needs no power to program using the PC Interface – uses power from paral-
lel port of PC
-Specifications May Change Without Notification
GSC300 Specifications (Continued)
IV

OGSC300 08/12
1
1. GSC300 PRODUCT NUMBER IDENTIFICATION
The GSC300 series catalog order number provides information pertaining to a specific model. The
Product Number Identification Table (see Table 1) provides details on the breakdown of the model
number.
INSTRUCTIONS
Following these instructions will help avoid common installation problems during wiring and setup.
• Battery must be disconnected before any wiring connections are made.
• Wire length from the engine to the controller should not exceed 6 meters (20 feet).
Wiring size and type should be as specified below. Use stranded wire, since solid wire has a tendency to
crack, break and loosen over time.
Danger: Never work on the engine while its power is on. This controller does
not generate a warning signal prior to automatic engine start. Warning signs should
be placed on engine equipment indicating this important safety measure.
Example: The product number GSC300-L-12-LS would be described as follows:
A GSC300 series automatic engine controller configured for a 12 VDC system.
The controller is factory configured for low speed range (generator speed range) which includes standard
labeling. A GSC300 serial number would be displayed as:
GSC300-L-12-LS-00000
2 WIRING INSTALLATION GUIDELINES
Position 1-6 Position 8 Position 10-11 Position 13-14
Series Speed Range DC Voltage Labeling
GSC300=GSC300 L=Low
H=High (Consult Factory) 12=12 VDC 24=24 VDC LS=Standard LX=Customized
Table 1 - IDENTIFICATION TABLE

OGSC300 08/12
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2 WIRING INSTALLATION GUIDELINES (CONTINUED)
Types and Sizes:
Terminal Wire Size (AWG) Current Max Function
1 12 40A Fuel Output Terminal
2 12 40A Auto(Battery +) Terminal Connection
3 12 40A Auto(Battery +) Terminal Connection
4 12 40A Crank Output Terminal
5 12 40A Ground Terminal Connection
6 12 40A Ground Terminal Connection
7 12 40A Preheat/ETS Terminal
8 12 40A Preheat/ETS Terminal
9 18 100mA Speed Signal Connection
10 18 100mA Speed Signal Connection
11 18 300mA Overcrank (failure to start) Output
12 18 300mA Overspeed Output
13 18 300mA High Termp Output
14 18 300mA Low Oil Output
15 18 300mA Low Battery Output
16 18 300mA Engine Run Output
17 18 100mA Not InAuto Output
18 18 300mA General Failure Output
19 18 7ma Start/Stop Input
20 18 7mA Oil Pressure Sender/Switch Input
21 18 7mA Temperature Sender/Switch Input
22 18 7mA Fuel Level/Auxiliary Sender/Switch Input

OGSC300 08/12
3
2-1 WIRING GUIDELINES
1. DO NOT use wire smaller than 18AWG as smaller wire has a tendency to crack and break over time.
2. IMPORTANT: The connections supplying DC power to the GSC300 panel should preferably run
directly from the battery posts with no splices or other connections. Avoid using chassis (aluminum or iron
engine parts), as return conductor for battery negative voltage. Copper wiring is recommended. Failure
to follow the above may result in erratic operation due to large voltage drops across wiring connections.
A small fuse should be placed at the battery terminal to provide 12 volts to the Remote Start Contacts to
ensure that a short along this line will not cause any damage.
3. DO NOT exceed the maximum rated current and voltage on each of the controller outputs. DO NOT
exceed 40A each for the Fuel Output, Crank Output or Preheat Output. DO NOT exceed 300mA individu-
ally, or 350mA combined, for the General Fault Output or Annunciation Outputs.
4. 40Amp relays are rated for resistive ratings. When driving such loads as starter solenoids you must
ensure proper de-rating of the relays. Consult factory for further details.
5. Engine Sensor type MUST be selected and programmed properly to GSC300 (switch or sender type).
Failure to do so may result in the controller not shutting down on true engine failure (Low oil pressure or
high engine temperature).
6. When installing engine sensors (oil pressure, engine temperature, fuel level) ensure the switches are
connected to ground circuit through the engine sensor. Damage will occur to controller unit if the
sensor
input terminals (Terminal #’s 20, 21 and 22) are connected to +Battery.
7. When using engine sensors that are the resistive type the proper manufacturer of the sender
MUST
be selected during programming. Failure to select the correct manufacturer type will cause inaccurate
readings as well as failure to protect the engine during a fault condition.
8. To verify the operation of engine controller outputs, measure voltage (i.e. meter in volts) when outputs
should be ON.
9. To verify the operation of the Preheat Output, measure the resistance between the Preheat terminals
when the Preheat Output is ON, it should read a closed circuit (i.e. zero ohms). When the output is OFF
there should be an open circuit between the terminals (very high resistance).
10. Speed sensing input terminals (Terminal #’s 9 and 10) do not have polarity sensitivity therefore the
AC generator output leads can be connected in any polarity configuration to the controller speed sensing
terminals. Do not exceed 300VAC on speed sensing input terminals.

OGSC300 08/12
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2-2 12/24VDC SYSTEM OPERATION
The GSC300 controller is designed to operate in either 12 or 24VDC system voltages. When operating in
12VDC systems the Fuel and Preheat/ETS relays need to be the 12VDC relay type. When operating in
24VDC systems these relays need to be the 24VDC relay type. Contact the factory if relays are required. 24
VDC will require reprogramming.
Approved relays for 12 or 24VDC system operation are as follows:
• Northern Lights P/N 22-42047 for 12VDC operation
• Northern Lights P/N 22-40085 for 24VDC operation
12VDC RELAYS MUST
BE INSTALLED FOR 12VDC
SYSTEM OPERATION
24VDC RELAYS MUST
BE INSTALLED FOR 24VDC
SYSTEM OPERATION

OGSC300 08/12
5
2-3 TERMINAL DESCRIPTION
Term # Description
1 Fuel Output provides 40A maximum. Fuel Output closes to +12/24VDC when start signal is received,
and opens when either an engine failure occurs or when Cool Down period has ended.
2, 3 Main +Battery power connection to controller. These terminals are internally connected together on
GSC300 controller.
4 Crank Output provides 40A maximum. Crank Output closes to +12/24VDC during cranking, and opens
when the engine has started, or during Crank Rest.
5, 6 Main Battery Ground connection for the controller module. A good ground connection, directly from
the battery, is required for proper operation. These terminals are internally connected together on
GSC300 controller.
7, 8 Preheat/ETS Output provides a set of dry contacts between terminals #7 and #8. When this output is
energized terminals #7 and #8 are connected together. When output is OFF terminals #7 and #8 have
no connection.
9, 10 Speed Signal Input for Crank Disconnect, Engine Run, and Overspeed sensing. 300VAC max input
voltage. Speed sensing input terminals (T#9, 10) do not have polarity sensitivity therefore the AC gen-
erator output leads can be connected in any polarity configuration. Do not exceed 300VAC on speed
sensing input terminals.
11 Overcrank Annunciation Output closes to +12/24VDC on Overcrank Failure. 300mA max.
12 Overspeed Annunciation Output closes to +12/24VDC on Overspeed Failure. 300mA max.
13 High Temp Output closes to +12/24VDC upon High Temp Failure. 300mA max.
14 Low Oil Output closes to +12/24VDC upon Low Oil Failure. 300mA max.
15 Low Battery Output closes to +12/24VDC on Low Battery Condition. 300mA max.
16 Engine Run Output closes to +12/24VDC on Engine Run Condition. 300mA max.
17 Not In Auto Output closes to +12/24VDC when unit is not in auto. 300mA max.
18 General Failure Output closes to +12/24VDC on a General Failure. 300mA max.
19 Start Stop Input. Apply +12/24VDC to this terminal while unit is in Auto Mode to start engine. Remove
+12/24VDC to stop engine or enter Cool-Down mode.
20 Low Oil Pressure sensor input. This sensor can be the resistive type (Sender) or can be the switch
type. The proper type of sensor must be selected during GSC300 controller programming. The sender
or switch must be connected to ground for proper operation. If +Battery is connected to input terminal
this can result in damaged to GSC300 controller. When using a sender, the proper sender manufac-
turer must be selected as each sender manufacturer’s characteristics are different; the sender failure
set-point must also be selected. When using a switch NO or NC much be selected from the program-
ming menu. NO refers to the state of the contacts during normal engine operation, therefore NO refers
to normally open at normal engine run and close to ground on low oil pressure failure.
21 High Engine Temperature sensor input. This sensor can be the resistive type (Sender) or can be the
switch type. The proper type of sensor must be selected during GSC300 controller programming. The
sender or switch must be connected to ground for proper operation. If +Battery is connected to input
terminal this can result in damaged to GSC300 controller. When using a sender, the proper sender
manufacturer must be selected as each sender manufacturer’s characteristics are different; the sender
failure set-point must also be selected. When using a switch the switch must be the NO type on normal
engine run and close to ground on failure.
22 Fuel Level sensor or Auxiliary failure input. This sensor can be the resistive type (Sender) or can be
the switch type. The proper type of sensor must be selected during GSC300 controller programming.
The sender or switch must be connected to ground for proper operation. If +Battery is connected to in-
put terminal this can result in damaged to GSC300 controller. When using a sender, the proper sender
manufacturer must be selected as each sender manufacturer’s characteristics are different. When us-
ing a switch the switch must be the NO type on normal engine run and close to ground on failure.
Table 2 Terminal Description

OGSC300 08/12
6
2-4 WIRING CONNECTION DIAGRAM
Figure 1 - Wiring Connections for the GSC300
(Refer to schematic No. C- 6827 on page 14)
2-5 BACK PANEL LAYOUT

OGSC300 08/12
7
3 CONTROLLER OPERATION
OFF/AUTO/RUN Modes On power up the controller defaults to the mode it was in when power was last removed (AUTO or
OFF). OFF mode can be entered by pressing the OFF button on the front panel. When the GSC300 is in the OFF mode the “Not
In Auto” LED will be lit on the front panel (NOT INAUTO below).
When the GSC300 is in the OFF mode, starting – either from the remote start contacts or from the front panel run button – is
disabled. To start the genset the GSC300 needs to be placed in the AUTO mode by pressing theAUTO button on the front panel.
Once in AUTO mode the genset can be started by pressing the RUN button. Once crank success is achieved (i.e. engine has
started), the GSC300 enters the RUN mode and the front panel ENGINE RUNNING LED will be lit.
GENERAL FAILURE CONDITIONS: The following conditions can cause the GSC300 controller to shutdown the
engine-generator system unexpectedly:
Auxiliary Failure (“XTR_FAIL”) Extra failure is indicated by a flashing RED Low oil pressure LED
Low Oil Pressure Low Oil pressure is indicated by a steady on RED Low oil pressure LED
High Coolant Temperature High coolant temperature is indicated by a steady on RED High water temp LED
Overcrank Overcrank failure is indicated by a steady on RED Overcrank LED
Overspeed
Overspeed failure is indicated by a steady on RED Overspeed LED
Loss of Speed (“SPDLOSS”) Loss of speed signal is indicated by a flashing RED Overspeed LED
NOT IN AUTO: When the controller is in the OFF Mode, the NOT IN AUTO LED will illuminate and the NOT IN AUTO Output will
be triggered. During this OFF mode Automatic engine starting is disabled. The LCD display will read “OFF”, and the backlight on
the LCD display will be off.
NOTE: + Battery must be permanently connected to the main power terminal for the NOT IN AUTO feature.
LOW BATTERY VOLTAGE ALARM: When the battery voltage drops below the user defined set point which can be programmed
between 7 and 35VDC, the engine controller displays a Low Battery Condition. The Low battery warning Led will be illuminated
at any time during OFF, AUTO and Manual run modes. The LCD display will indicate the message: “LOW_BATT”. The LOW
battery warning will be disabled during failure conditions.
LOW OIL INPUT: The Low Oil Input can be wired to a resistive sender or from a NO or NC type switch. NO / NC refers to the
state of the contacts during normal engine operation (engine oil pressure ok). When utilizing a resistive sender the display units
are fixed in PSI by the PC programming interface, and a failure set-point must be selected from the programming menu.
Note: The oil input failure is disabled during the Oil Bypass time.
HIGH TEMPERATURE INPUT: The high temperature input can be wired to a resistive sender or from a NO type switch. For
proper operation while using a switch, the switch must be the NO type which closes to ground upon failure. When utilizing
a resistive sender the display units are fixed in Fahrenheit by the PC programming interface, and a failure set-point must be
selected from the programming menu. Note: The engine temperature failure is disabled during the Oil Bypass time.
FUEL LEVEL/AUXILIARY INPUT: The Fuel level/Aux input can be wired to a resistive sender or from a NO type switch. For
proper operation while using a switch, the switch must be the NO type which closes to ground upon failure. If this input is used
as a sender, no failure will be indicated. The sender option is solely for Fuel Level/Auxiliary Level Display on the LCD. Northern
Lights, Inc. uses this input to connect the engine shutdown switches as a backup to the primary shutdown inputs.
SPEED SIGNAL SENSITIVITY: The controller will accept to a maximum of 300VAC, 60Hz from direct generator output for speed
sensing. The following values are minimal recommended voltages for speed signal sensing:
20Hz - .075V (75mV)
60HZ - .6V (600mV)
HOUR METER: The controller displays a log of total accumulated generator running hours. Generator Run times will be
displayed on the controllers display screen. The display represents both hours and minutes in the form 123456:7. The last digit
on the hour meter will represent the time in 1/10 of an hour. Please note that although the hour meter displays time in hours and
minutes, it will record up to the nearest second. If the generator was operated for a 3 minute period and then stopped the running
time is stored in permanent memory and then adding to the next running period. The same would be true if the controller were to
enter a failure mode as the controller would permanently store the remaining time for the next running cycle.
Updated 8-2-12
3-1 CONTROLLER OVERVIEW

OGSC300 08/12
8
3-2 LED LAYOUT
Table 3: FRONT PANEL LED INDICATORS
Figure 3 - Front View of GSC300
3-3 LED INDICATIONS
LED Appearance Condition/Failure
Not in Auto LED is ON. Unit is in OFF state, and automatic starting is disabled
No LED’s ON “OFF”, no +12/24VDC to main power terminal.
Steady Low Oil LED Low Oil Pressure Failure
Flashing Low Oil LED Auxiliary Input Failure
Steady High Temperature LED Over Temperature Failure
Steady Overcrank LED Engine-generator failed to start after the specified number of cranking
attempts.
Steady Overspeed LED Speed Signal present above Overspeed setting
Flashing Overspeed LED The speed signal was Zero while running. The engine has stalled (over-
load or lack of fuel), or the speed signal has been lost.
Steady Engine Running LED Engine Controller is in running mode of operation.
Flashing Engine Running LED Crank Rest period. Cranking will resume soon.

OGSC300 08/12
9
4 PROGRAMMING THE GSC300 SETTINGS
Using the Front Panel Interface:
The following table shows the LED’s that correspond to the various settings of the various param-
eters. To enter the controller into Program Mode, you need to turn the small switch at the bottom
edge of the controller to the program position (See Diagram on Pg 5). This Mode Switch can be
set using a ballpoint pen or small tool to allow the controller to be put into Program Mode. The first
three LED’s (3, 2 & 1) correspond to which Parameter is being adjusted, and the next three (6, 5
& 4) LED’s show the Value for that particular Parameter.
LED 1 = Low oil pressure
LED 2 = High water temp
LED 3 = Overcrank
LED 4 = Overspeed
LED 5 = Engine Running
LED 6 = Low engine battery
LED 7 = Preheat/ETS
LED 8 = NOT INAUTO (starting disabled)
The picture on the next page shows the LED numbering and the location of the Mode Switch.
The highlighted circle in the table refers to the LED being illuminated.
Parameter LED’s 3,2 &1 LED’s 6,5 &4
Crank Tries 12345678
Crank Time 510152025303540
Rest Time 0 5 10 15 20 25 30 35
Preheat Time 0 5 10 15 20 35 30 35
Cool-Down 0 32 64 96 128 160 192 224
Preheat/ETS/
Warm-up
Pre-
heat
ETS Warm-
Up
N/A N/A N/A N/A N/A
Warm-Up 0 28 56 84 112 140 168 196
To scroll through the parameters simply press the Auto button on the front panel of the
GSC300. To scroll through the range of values for that parameter simply press the Manual
Start button. To program the value into the controller’s memory, press the OFF button. In
this manner the settings of the controller can be adjusted by simply using the three buttons on
the front panel of the controller. Be sure to press the OFF button when you have selected the
parameter value wanted.

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4-1 NUMBERING OF LED’S AND LOCATION OF MODE SWITCH
Programming Using the PC Interface
The GSC300 can also be programmed using the PC interface. Detailed instructions on the
PC interface are included with the GSC300 Configurator software. A sample interface screen is
illustrated on the following page.

OGSC300 08/12
11
4-2 SAMPLE SCREEN FROM PC INTERFACE
NOTE: Factory default settings are outlined in the photo below.
Figure 5:

OGSC300 08/12
12
5 TROUBLESHOOTING GUIDELINES
TROUBLE POSSIBLE CAUSE SUGGESTED ACTION
Unit does not operate when
powered to test mode Power leads to unit are reversed Confirm correct wiring for ground and +bat, and re-attempt testing.
Bad ground connection from engine to
controller unit. Run wire directly from battery - to the ground terminal #5 & 6 on controller unit.
Engine starts and immediately
goes into Overspeed shut-
down
Improper Overspeed setting Verify the Overspeed setting with PC configu-
ration software. Confirm that engine’s governor
is properly calibrated for its intended use.
Engine does not crank Battery is low or terminals are dirty Clean terminals and re-charge battery
Crank circuitry wiring improperly
connected Refer to engine control wiring section and check crank connections
Bad ground connection from engine to
controller Run wire directly from battery - to the ground terminal #5 & 6, on controller unit.
Crank relay damaged or on board fuse
is blown Check wiring, in line fuse and slave relay. Replace fuse, relay and re-test controller
Engine cranks but does not
start Out of fuel Check fuel level, add fuel if necessary
Ignition control wiring not installed
properly Refer to engine control wiring section and check ignition connections
Fuel relay and/or fuse damaged Check fuel relay and fuse, replace if damaged
or blown.
Engine starts but shuts down
after “Oil BypassTM period”
due to low oil/high temp/Aux
input
Oil/Temp/Auxiliary input wiring improp-
erly connected. Check wiring for proper connections.
Incorrect programming of sensor inputs. Check programming of oil pressure, engine
temperature and aux input. Ensure that the
sensor type is properly programmed to control-
ler unit (Sender / Switch type)
Flashing Overspeed LED Speed signal improperly connected,
missing, or damaged. Check speed signal wiring; replace damaged speed signal source
Crank output damaged, not working, or
fuse blown on starter output Check wiring and replace relay of fuse where necessary.
Starter or starter solenoid damaged Replace/repair damaged starter or starter
solenoid.
Steady Oil LED immediately
on start-up, without engine
actually cranking or starting.
False speed signal being detected by
controller. This problem can sometimes
occur in installations where there is AC
power from inverters near generator
output lines connected to the speed
signal cable.
Install a small step down transformer between
the speed sensing wires and the generator
output.
If the neutral from the generator output is not
grounded, attach it to ground.
Display Parameter for Tem-
perature, Oil or Fuel displayed
as >>> or <<<
Parameter is >>> ABOVE or <<<
BELOW specified manufacturer sender
range.
If further accuracy is required it may be
necessary to install sender with proper range
specifications.
Warm-Up Feature appears
longer than time setting. Warm-Up Feature time setting does not begin until the Oil Bypass Time has
expired.
Re-adjust Oil Bypass and/or Warm-Up timing.
Engine cranks immediately
when battery is started up. GSC300 was in autostart when battery was disconnected. Make sure GSC300 is shut off prior to battery being disconnected.
GSC300 was in autostart and battery
was dead when charger was hooked up
Press off when hooking up charger.
Battery Discharged.
(Low battery voltage alarm.) GSC300 has a 45 ma load in standby mode Use a battery disconnect switch, install a larger battery, or install a battery charger/
maintainer.

OGSC300 08/12
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6 TECHNICAL NOTES ON FREQUENTLY ASKED QUESTIONS
1. Controller Memory Clear Time
The GSC300 needs 10 seconds for its memory to clear. When the power to the controller is turned
off and then back on again without waiting 10 seconds to clear the memory, a loss of speed will may
be indicated by the GSC300 (if controller is in AUTO mode and start signal is activated) because the
controller remains in run mode and senses that the generator has stopped. This would be indicated by a
Flashing Overspeed LED. By leaving the GSC300 main power OFF for 10 seconds before main power
is re-applied this allows the clearing the memory and it will function as intended.
2. Step Down Transformer Use On Speed Sensing Cable With Inverter Systems
In some applications engine controllers are used on generators where there is no utility connection and
inverters are used to provide AC power instead of a utility. Inverters can produce harmonics that can
cause small AC signals to appear on wires that are near any power lines being fed by the inverter. If the
generator output wires are located close to a line being powered by an inverter, a small AC signal can
appear on the generator output lines when the inverter is on. This signal can cause the engine controller
to react as if the generator is running if the speed sensing wires are connected to the generator output
lines. This smallAC signal can cause the controller to appear to have a Low Oil Failure when the remote
start contacts are closed or the controller is put in the manual/test mode. The controller may think the
generator is already running and immediately check to make sure there is oil pressure. Since the engine
really hasn’t started yet, there is no oil pressure and the controller sees a low oil fault. This is seen as
the Oil LED turning on steady even before the engine starts to engage the starter.
Without this false speed signal the controller will not look for oil pressure until the engine has started to
run and the crank disengages if oil verification is disabled. Simply installing a small transformer between
the generator output and the speed sensing terminals on the controller can eliminate this false speed
signal. This transformer should be rated for 120 or 240 volts on the input or primary coil (depending on
the generator output voltage you are using for speed sensing), and have an output voltage of around
12VAC on the secondary of the transformer. The two wires from the secondary of the transformer are
connected to the two wires of the speed sensing terminals on the GSC300 controller. The step-down
transformer acts to reduce the false speed signal on the line to a level that the engine controller will not
recognize as the engine running. A common size transformer that would serve this purpose would be
24VA.
Figure 6: Step Down Transformer Connections on Speed Sensing Cable

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