Woodward APECS 4500 User manual

SE-4097
APECS
®
4500 Electronic
Engine Speed Governing System
User Manual
Manual SE-4097

WARNING
Read this entire manual and all other publications pertaining to the work to be
performed before installing, operating, or servicing this equipment. Practice all
plant and safety instructions and precautions. Failure to follow instructions can
cause personal injury and/or property damage.
The engine, turbine, or other type of prime mover should be equipped with an
overspeed shutdown device to protect against runaway or damage to the prime
mover with possible personal injury, loss of life, or property damage.
The overspeed shutdown device must be totally independent of the prime mover
control system. An overtemperature or overpressure shutdown device may also be
needed for safety, as appropriate.
CAUTION
To prevent damage to a control system that uses an alternator or battery-charging
device, make sure the charging device is turned off before disconnecting the battery
from the system.
Electronic controls contain static-sensitive parts. Observe the following precautions
to prevent damage to these parts.
• Discharge body static before handling the control (with power to the control
turned off, contact a grounded surface and maintain contact while handling the
control).
• Avoid all plastic, vinyl, and Styrofoam (except antistatic versions) around
printed circuit boards.
• Do not touch the components or conductors on a printed circuit board with
your hands or with conductive devices.
IMPORTANT DEFINITIONS
WARNING—indicates a potentially hazardous situation which, if not avoided, could
result in death or serious injury.
CAUTION—indicates a potentially hazardous situation which, if not avoided, could
result in damage to equipment.
NOTE—provides other helpful information that does not fall under the warning or
caution categories.
Woodward Governor Company reserves the right to update any portion of this publication at any time. Information
provided by Woodward Governor Company is believed to be correct and reliable. However, no responsibility is
assumed by Woodward Governor Company unless otherwise expressly undertaken.
© Woodward 2004
All Rights Reserved

Manual SE-4097 APECS
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4500 Electronic Engine Speed Governing System
Woodward i
Contents
E LECTROSTATIC D ISCHARGE A WARENESS ................................................. IV
C HAPTER 1. G ENERAL I NFORMATION ..........................................................1
System Basics ........................................................................................................1
Figure 1. APECS Engine Control SystemSystem Components ............................1
System Components ..............................................................................................2
APECS Controller ...........................................................................................2
All-Purpose Calibration Tool (ACT) ................................................................2
Speed Sensor .................................................................................................2
Actuator...........................................................................................................3
Linkage ...........................................................................................................3
Features Table................................................................................................5
Engine Speed Select Options Table...............................................................6
C HAPTER 2. I NSTALLING THE H ARDWARE ...................................................7
Wiring Guidelines ...................................................................................................7
Wiring Length..................................................................................................8
Controller Installation..............................................................................................9
Controller Wiring.............................................................................................9
Controller Pinout ...........................................................................................11
Speed Sensor Installation.....................................................................................12
Guidelines.....................................................................................................12
Speed Sensor Wiring....................................................................................12
Actuator & Linkage Installation .............................................................................13
Engine Speed Setpoint Wiring—Analog Input......................................................14
Guidelines.....................................................................................................14
Engine Speed Setpoint Wiring—Switched Inputs.................................................15
Guidelines.....................................................................................................15
Switch Wiring ................................................................................................15
Power Take-off Input Wiring.................................................................................16
Glowplug Wiring ...................................................................................................17
Autocrank Wiring ..................................................................................................18
Auxiliary Output Wiring .........................................................................................18
Engine Protection Input Wiring .............................................................................19
Optional Feature ...........................................................................................19
C HAPTER 3. ACT O PERATION ..................................................................20
ACT Installation ....................................................................................................20
ACT Kit Contents ..........................................................................................20
Set-up Requirements....................................................................................20
Hardware Set-up...........................................................................................20
Software Set-Up............................................................................................21
Basic ACT Operation............................................................................................22
Running the ACT Software ...........................................................................22
Progress Display Screen ..............................................................................22
Moving Around the Software.........................................................................22
ACT Menus & Options..........................................................................................23
ACT Menu Structure .....................................................................................23
File Menu..............................................................................................................23
Purpose.........................................................................................................23
Save APECS Cal to File ...............................................................................24
View Cal File Comments ..............................................................................25
View Text File ...............................................................................................25
Convert Commands......................................................................................26
Convert APECS Cal to Text..........................................................................26
Convert Cal File to Text ................................................................................26

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4500 Electronic Engine Speed Governing System Manual SE-4097
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Convert Cal File to Strategy..........................................................................26
Calibrate Menu......................................................................................................27
Change APECS Calibration ..........................................................................27
Download Cal File to APECS........................................................................28
Compare APECS Cal to File Cal ..................................................................29
Change APECS Password ...........................................................................30
APECS Calibration Wizard ...........................................................................32
Monitor Menu........................................................................................................32
Parameter View ............................................................................................33
Parameter Plot..............................................................................................33
Display Faults................................................................................................35
Control Strategy ............................................................................................35
Parameter List...............................................................................................35
Configure Menu ....................................................................................................37
Configure Serial Port.....................................................................................37
Help Menu.............................................................................................................38
Help Topics...................................................................................................38
About ACT ....................................................................................................38
User’s Manual...............................................................................................38
C HAPTER 4. C ALIBRATING APECS F EATURES ..........................................39
Calibration Guide ..................................................................................................39
Safety Precautions........................................................................................39
Calibration Categories ..................................................................................39
Calibrating an APECS Unit ...........................................................................40
Saving a Calibration Set to File.....................................................................40
Calibrating an APECS Unit with a Saved Calibration File.............................41
Understanding APECS Calibration Parameters ...................................................42
Frequently Asked Questions.........................................................................42
List of Parameters.........................................................................................43
Calibration Procedures: PID Gains Adjustment....................................................45
PID Gain Settings Response Plots ...............................................................45
Engine Set Speed Calibration Parameters ...........................................................46
Calibration Procedures .................................................................................46
External Analog Input Calibration (with IVS).........................................................48
Switch Configuration Modes .................................................................................50
External Pot Calibration ........................................................................................51
Calibration Procedures .................................................................................51
PTO Input .............................................................................................................52
Calibration Procedures .................................................................................52
Set Speed Calibration FAQ...................................................................................52
Speed Input Configuration Parameters ................................................................53
Calibration Procedures .................................................................................53
PULSES_PER_REV FAQ.............................................................................54
Engine Start Calibration Parameters ....................................................................55
Glowplug Control...........................................................................................55
Autocrank......................................................................................................55
Engine Cranking ...........................................................................................56
Diagnostics Calibration Parameters .....................................................................57
Engine Protection Input.................................................................................57
Overspeed / Underspeed Protection.............................................................58
Overspeed FAQ............................................................................................59
Actuator Output Calibration Parameters...............................................................59
Actuator Current Protection ..........................................................................59
Auxiliary Outputs...........................................................................................62
Droop Governing...........................................................................................63
Calibration Setup & Configuration Parameters Flowchart ....................................64
C HAPTER 5. T ROUBLESHOOTING ..............................................................68
General Checklist .................................................................................................68

Manual SE-4097 APECS
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4500 Electronic Engine Speed Governing System
Woodward iii
Fault Codes ..........................................................................................................68
Glossary of Technical Terms................................................................................70
C HAPTER 6. S ERVICE O PTIONS ................................................................71
Product Service Options.......................................................................................71
Replacement/Exchange................................................................................71
Flat Rate Repair............................................................................................72
Flat Rate Remanufacture..............................................................................72
Returning Equipment for Repair ...........................................................................72
Packing a Control..........................................................................................72
Return Authorization Number .......................................................................73
Replacement Parts ...............................................................................................73
How to Contact Woodward...................................................................................73
Engineering Services............................................................................................74
Technical Assistance............................................................................................75

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4500 Electronic Engine Speed Governing System Manual SE-4097
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Electrostatic Discharge Awareness
All electronic equipment is static-sensitive, some components more than others.
To protect these components from static damage, you must take special
precautions to minimize or eliminate electrostatic discharges.
Follow these precautions when working with or near the control.
1. Before doing maintenance on the electronic control, discharge the static
electricity on your body to ground by touching and holding a grounded metal
object (pipes, cabinets, equipment, etc.).
2. Avoid the build-up of static electricity on your body by not wearing clothing
made of synthetic materials. Wear cotton or cotton-blend materials as much
as possible because these do not store static electric charges as much as
synthetics.
3. Keep plastic, vinyl, and Styrofoam materials (such as plastic or Styrofoam
cups, cup holders, cigarette packages, cellophane wrappers, vinyl books or
folders, plastic bottles, and plastic ash trays) away from the control, the
modules, and the work area as much as possible.
4. Do not remove the printed circuit board (PCB) from the housing unless
absolutely necessary. If you must remove the PCB from the housing, follow
these precautions:
•Do not touch any part of the PCB except the edges.
•Do not touch the electrical conductors, the connectors, or the
components with conductive devices or with your hands.
•When replacing a PCB, keep the new PCB in the plastic antistatic
protective bag it comes in until you are ready to install it. Immediately
after removing the old PCB from the control cabinet, place it in the
antistatic protective bag.
CAUTION
To prevent damage to electronic components caused by improper handling,
read and observe the precautions in Woodward manual 82715, Guide for
Handling and Protection of Electronic Controls, Printed Circuit Boards, and
Modules.

Manual SE-4097 APECS
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4500 Electronic Engine Speed Governing System
Woodward 1
Chapter 1.
General Information
System Basics
APECS is an acronym for Advanced Proportional Engine Control System. It provides a
means of controlling engine speed by adjusting the fuel control lever with an actuator.
The heart of the system is a powerful microprocessor-based controller that processes
the signal received from a speed sensor and compares it to the desired speed setting.
The output of the controller is a pulse-width modulated signal that drives a precision
proportional actuator connected to the engine’s fuel control lever. The actuator converts
the signal to an output shaft position, proportional to the duty cycle of the pulse-width
modulated signal.
The APECS system provides isochronous engine governing (i.e., engine speed is
maintained at the commanded setting, regardless of load) through a wide speed range.
APECS is suitable for use on both compression ignition (diesel) and spark ignition
(gasoline, CNG, LPG) engines.
Woodward developed the APECS system for a variety of on- and off-highway
applications. Typical applications include generator sets, compressors, construction
machinery and farm vehicles.
WARNING
An overspeed shutdown device, independent of the APECS system, should
be provided to prevent loss of engine control that may cause personal injury
or equipment damage.
Figure 1. APECS Engine Control System

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System Components
The five main components of the system are the APECS controller, all-purpose calibration tool
(ACT), speed sensor, actuator, and linkage. In addition to the main components, and depending
on the features selected, there are several subcomponents (such as speed switches and
potentiometers). Each component contributes to the overall performance of the system and
shortcomings in any of the components will detract from total system performance.
APECS Controller
The APECS 4500 series controller is an electronic engine
governor that provides a means of controlling and limiting
engine speed by adjusting the fuel control lever with a
proportional actuator. The APECS controller may be
programmed to operate at up to four different speeds. It also
operates in either isochronous or droop mode, where droop is
user selectable up to 15%.
The controller is software programmable and has no manual adjustments. A calibration tool
(ACT) is used for programming (configuring and adjusting) the APECS 4500 controller.
All-Purpose Calibration Tool (ACT)
ACT is a PC (personal computer) based software calibration and
monitoring tool. ACT is designed specifically for use with engines
equipped with the APECS 4500 controller. The tool can be run on any
IBM compatible computer that meets the requirements listed in “ACT
Installation” in Chapter 3.
Once the APECS 4500 controller has been programmed, ACT may be
disconnected. The APECS 4500 unit will continue to operate normally
with ACT either connected or disconnected.
Speed Sensor
APECS 4500 monitors engine speed continuously. Engine speed may be sensed by
monitoring the frequency of spark events in spark-ignition engines or through the use of a
sensor that detects the passing of teeth on an engine driven gear (e.g., flywheel).
The universal speed input of the APECS 4500 is compatible with the following types of speed
input signal:
• Magnetic Pickup. Magnetic pickups are available from Woodward
• Coil-type Spark Ignition. Speed can be sensed from the negative side of the coil
primary winding.
• Magneto Spark Ignition. Speed can be sensed from the spark kill wire on the
primary winding, but will not work if a diode is placed between the magneto and
the APECS input (may be found on some multi-cylinder engines with magneto
ignitions.
• Hall-Effect Sensor

Manual SE-4097 APECS
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4500 Electronic Engine Speed Governing System
Woodward 3
Actuator
The actuator converts a pulse-width modulated signal received from the controller to an
output shaft position proportional to the duty cycle of the pulse-width modulated signal.
The actuator is mounted on the engine and
connected to the control lever by a mechanical
linkage.
NOTE: On spark ignition engines, the control lever
is usually the throttle lever. On compression
ignition engines (diesels), the control lever is
usually one of the mechanical governor levers
(either shutoff or governor).
Linkage
The linkage connects the actuator shaft to the engine
control lever. A good linkage allows for misalignments
and contributes to accurate, stable and responsive
performance with minimal play or friction.
NOTE
The scope of this manual does not include selection and installation
of speed sensors, actuators, or linkages that Woodward offers for use
with the APECS system. Information is available on our website at
www.woodward.com.
NOTE
The need for sub-components such as switches and potentiometers is
application dependent. Please contact Woodward for information
specific to your application.

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4500 Electronic Engine Speed Governing System Manual SE-4097
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Programmable Features
The APECS 4500 expands Woodward’s line of programmable engine governors to address the
needs of the mobile equipment industry. Enhanced input and output capability, combined with a
flexible configuration, permits the controller to easily adapt to a wide variety of engine governing
applications.
Following is a list of features available with the APECS 4500.
• Analog Speed Setpoint Input: suitable for use with a potentiometer or an
accelerator pedal position sensor (idle verification available)
• Actuator Current Protection: protects actuator from burning out
• Autocrank: useful for remote operation of engines using an auxiliary output.
• Auxiliary Outputs: two outputs which can be configured to drive lamps or relays
• Droop Governing: allows non-isochronous speed governing
• Engine Protection Input: protects against adverse conditions such as loss of
engine oil pressure or excessive coolant temperature
• Engine Start Calibration: useful for applications that require special startup
operation (e.g. warm-up speed, reduced governor gains, missing speed signal)
• Glowplug Control: useful for enhancing cold start capability of a diesel engine
using an auxiliary output
• Historic Fault Codes: retains a record of past fault codes, even after loss of
battery power.
• Overspeed / Underspeed Protection
• PID Gain Adjustment: allows governor response to be adjusted by user
• PTO Switch Input: allows selection between analog speed setpoint input and
switched speed setpoint inputs in mobile applications
• Switched Speed Setpoint Inputs: allow multiple speed settings using switches.
This feature can be configured together with the analog input (speed pot) for a
variety of speed select options.
• Universal Speed Input: speed input is compatible with most common means for
sensing engine speed including mag pickup, ignition and Hall-Effect
To incorporate any of the above features in your system, refer to the Features Table below
to determine if additional hardware installation or software configuration is required.

Manual SE-4097 APECS
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4500 Electronic Engine Speed Governing System
Woodward 5
Features Table
All features available with the APECS 4500 can be easily installed and configured to
work with your application. Refer to the table below to determine if additional hardware
installation is required. Software setup is always required to properly configure the
feature.
Hardware required for the features is customer supplied and is not sold or supplied by
Woodward.
** See Engine Speed Select Options table below
To incorporate any of these features in your system refer to “Installing the Hardware
section to install the selected feature and “Calibrating APECS Features” chapter to
configure the feature for your application.
FEATURE ADDITIONAL HARDWARE
REQUIRED?
Actuator Current Protection No
Autocrank Yes
Auxiliary Output Yes
Droop Governing No
Engine Protection Input Yes
Engine Start Calibration No
Glowplug Control Yes
Overspeed / Underspeed Protection No
PID Gains Adjustment No
PTO Switch Input Yes
Analog Speed Setpoint Input** Yes
Switched Speed Setpoint Inputs** Yes

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4500 Electronic Engine Speed Governing System Manual SE-4097
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Engine Speed Select Options Table
The following speed select options are available with the APECS 4500.
SPEED SELECT OPTIONS
1
NO ANALOG INPUT
Use a speed switch to select up to 4
discrete speeds or use a momentary
switch to manually increase or
decrease speed at preset rates.
2
SPEED TRIM
Use a speed pot (analog input) to trim
the speed switch selected set speed.
3
SET SPEED WITH POT
Use a speed pot (analog input) to
adjust set speed.
4
SET SPEED WITH POT
OR SPEED SWITCH
Use a speed pot (analog input) to
adjust the set speed or use a speed
switch to select up to 4 discrete
speeds. Use the PTO switch to select
between speed pot and speed
switches.
5
DRIVE-BY-WIRE
Use pedal pot (analog input) to adjust
set speed. Can be used with or without
IVS. Includes safety startup logic to
assure engine always starts at idle.
6
DRIVE-BY-WIRE OR SPEED SWITCH
Use a pedal pot (analog input) to adjust
the set speed or use a speed switch to
select up to 4 discrete speeds. Can be
used with or without IVS. Use the PTO
switch to select between pedal pot and
speed switches. Drive-by-Wire mode
assures that the engine will never start
up at a high speed. Commanded speed
will remain at idle until the pedal
returns to idle. The PTO input must
undergo an off-to-on transition before
starting PTO mode.

Manual SE-4097 APECS
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4500 Electronic Engine Speed Governing System
Woodward 7
Chapter 2.
Installing the Hardware
When installing the APECS hardware, be aware that some of the options selected may
also require hardware setup (see list below). Hardware required for optional features is
not provided or sold by Woodward.
Take adequate protection to ensure personal and equipment safety and follow the
suggested installation sequence given below:
Install main components:
Wiring page 7
Speed Sensor page 12
Actuator & Linkage page 13
Install optional components (hardware installation required):
Engine Speed Setpoint—Analog Input page 14
Engine Speed Setpoint—Switched Inputs page 15
Power Take-off Input page 16
Glowplug page 17
Autocrank page 18
Auxiliary Output page 18
Engine Protection Input page 19
Wiring Guidelines
APECS 4500 has two 12-pin Deutsch connectors labeled J1 (grey) and J2
(black). Mating connectors may be purchased from Woodward (part number
SA-4490) or from a Deutsch distributor.
Deutsch part numbers are as follows:
J1 (Grey): DTM06-12SA
J2 (Black): DTM06-12SB
Sockets (pins, 12 per connector): 1062-20-0122
Wedgelocks (1 per connector): WM-12S
Blank Pins (to fill empty pins): 0413-204-2005
Always use an appropriate crimping tool for attaching the pins to the wiring harness.
Pay close attention to the pin numbers embossed on each connector.
Guidelines
Refer to Figures 2 & 3 and Tables 1 & 2 to install the system and subcomponents
Mount the unit in a location where the effects of vibration and temperature are within the
specified range. Operating temperature: -40°F to +185°F (-40°C to +85°C); vibration: 6
G’s from 40 to 2000 Hz. (See Figure 2 for controller dimensions.)

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4500 Electronic Engine Speed Governing System Manual SE-4097
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Power leads are to be connected directly to a switched power source (i.e., battery).
Use of a 10 amp, slow-blow fuse is recommended in the battery (positive) wire.
Use shielded cable for external speed signal source. Shields should be connected
to the battery ground wire at one end only.
Use of convoluted tubing, conduit or other wire shielding is recommended to
minimize the likelihood of mechanical damage to wires.
Avoid routing wires near sharp edges or near locations that can cause the wires
to be “pinched” or damaged.
Use proper gauges and lengths of wire as shown in Table 1. Wire insulation should
be appropriate for engine applications.
Excessive length or inadequate gauge can cause increased wire resistance
that can limit the current to the actuator and prevent full actuator travel
Increased electrical resistance can also result from poor wiring techniques. It is
important to use good quality terminations and proper crimping technique during
wiring.
Terminations must be impervious to moisture to prevent shorts and corrosion.
Wiring Length
Excessive resistance in the wiring will result in insufficient force from the actuator. Such
increased resistance can result from too much wire length, inadequate wire gauge, or
poor connections.
The following table shows the recommended gauges and maximum lengths of
connecting wires for different size APECS actuators. Wire length is the total length (to
and from) used to connect the actuator to the controller and the controller to the system
power.
NOTE: All system wiring should be twisted pair and shielded (preferably foil
shielded).
Table 1. System Wiring
ACTUATOR* AWG 14 (2.50 mm
2
) AWG 16 (1.50 mm
2
) AWG 18 (1.00 mm
2
)
0175 66 ft (20 m) 33 ft (10 m) 22 ft (6.7 m)
0250 46 ft (14 m) 23 ft (7 m) 15 ft (4.6 m)
0300 46 ft (14 m) 23 ft (7 m) 15 ft (4.6 m)
(*) The controller has a working range of 9-30 VDC. However, the actuator
must be selected for either 12 or 24 VDC charging system.

Manual SE-4097 APECS
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4500 Electronic Engine Speed Governing System
Woodward 9
Controller Installation
Controller Wiring
The controller can be installed in the engine compartment (maximum temperature
185°F / 85°C.)
Figure 2. APECS 4500 Dimensions

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4500 Electronic Engine Speed Governing System Manual SE-4097
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Table 2. Controller Wiring
FUNCTION PIN INFORMATION REMARKS
Actuator Output ACT+ (J1-5), ACT- (J1-8) —
Analog Input APP(J2-12), V
REF
(J2-11), RTN(J2-2) —
Auxiliary Output AUX (J2-4), V
BAT
(J1-9) Low side driver
Auxiliary Output #2 AUX 2 (J2-3), V
BAT
(J1-9) Low side driver
Battery VBAT (J1-9), GND (J1-4) —
Engine Protection Input EPSW (J2-9), GND (J1-4) Switch to Ground
Idle Verification IVS (J2-5), V
BAT
(J1-9) Switch to V
BAT
Power Take-off PTO (J2-6), V
BAT
(J1-9) Switch to V
BAT
Rack Position Sensor RPS (J2-1) Not Used
ACT Connector RCV (J1-12), TXD (J1-1), V
BB2
(J1-11),
GND2 (J1-2) —
Speed Signal Input RPM+(J1-10), RPM-(J1-3) —
Switched Inputs SW1 (J2-7), SW2 (J2-8), V
BAT
(J1-9) Switch to V
BAT

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4500 Electronic Engine Speed Governing System
Woodward 11
Controller Pinout
Use the diagram below to connect your APECS controller to ACT, your preferred speed sensor, and
various inputs and outputs.
Auxiliary Output
GND (J1 4)
VBAT (J1 9)
EPSW (J2 9)
Power (DC)
Engine Protection Input
RPS (J2 1) (not used)
PTO Switch Input
PTO (J2 6)
AUX (J2 4)
SW2 (J2 8)
SW1 (J2 7) Switched Speed Input
Proportional Actuator Output
Speed Sensor Input
Analog Speed Input
IVS (J2 5)
VREF (J2 11)
APP (J2 12)
SRTN (J2 2)
RPM- (J1 3)
RPM+ (J1 10)
ACT- (J1 8)
ACT+ (J1 5)
Idle Verification
(used with pedal input)
Slow Blow Fuse
(10 amp)
APECS 4500 Controller
Interface Module
4-pin mating connector
(Molex 39-01-2040)
Calibration Tool Setup
Twisted Pair Wire
(> 1 twist per inch)
Pot Pedal
RS-232 Cable Twisted Pair Shielded Wire
(shield grounded at controller only)
Magnetic Pickup
Switched to
Ground
Switched
to VBAT
Switched
to VBAT
Lamp Relay
Spark Ignition
Magneto Hall Effect
or
or
Twisted Pair Wire
(> 1 twist per inch)
12-24v output
Auxiliary Output 2
Lamp Relay
or
AUX2 (J2 3)
12-24v output
GND2 (J1 2)
VBB2 (J1 11)
TXD (J1 1)
RCV (J1 12)
Figure 3. APECS 4500 Wiring Diagram

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Speed Sensor Installation
Guidelines
There are four different speed-sensing devices that can be used with the APECS 4500
system.
1. Magnetic pickup
2. Spark ignition
3. Magneto
4. Hall Effect sensor
Refer to Table 2 and Figure 3 for guidance in selecting the speed sensor suitable for
your controller and application.
For magnetic pickups and Hall Effect Sensors, the mounting of the sensor unit must be
rigid; excessive vibration can cause erroneous signals and unreliable performance.
Use twisted pair shielded wire for all speed sensor wiring. Shield should be grounded at
the controller only.
Figure 4. Speed Sensor Wiring
Speed Sensor Wiring
Magnetic Pickup
Installed opposite an engine driven gear such as the flywheel,
it transmits a signal each time the magnetic flux path across
the pole is interrupted by a gear tooth.
Connect Pin J1-10 to the positive and Pin J1-3 to the negative
side of the sensor. Most sensors do not have a positive or
negative side and can be connected either way.
Spark Ignition
Intended for either traditional coil and distributor ignition or
distributorless ignition systems
Traditional coil and distributor ignition; 2-, 3-, 4-, 6- and
8-cylinder engines: Connect Pin (16) to the negative side of the coil
primary.
Distributorless ignition, 2-, 4-, 6- and 8-cylinder engines:
Connect Pin J1-10 to the negative side of one coil primary.
May not work with ignition systems that vary the coil charging voltage
(e.g. Ford TFI).

Manual SE-4097 APECS
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Magneto Ignition
Typically found on small 1- and 2-cylinder engines
Connect Pin J1-10 to the primary/engine kill wire and Pin J1-3
to the engine block.
Hall Effect
Located next to an engine driven gear
Connect Pin J1-10 to the sensor output and Pin J1-3 to the negative
side of the sensor. The third sensor lead should be connected to
battery positive.
NOTE: It is beyond the scope of this manual to discuss detailed speed sensor
selection and installation for all possible applications. Please contact the factory
for specific information concerning your application.
Actuator & Linkage Installation
1. Select actuator with sufficient force to move the fuel control lever from
minimum to maximum fuel position. The controller has a working range of 9-30
VDC. However, the actuator must be selected for either 12 or 24 VDC charging
system.
2. Select or design a bracket that correctly aligns the actuator shaft and control
lever and is able to withstand the vibration level of the engine or application.
3. The linkage must have minimal friction, binding and backlash. The bracket and
linkage should be designed to use as much of the actuator travel as possible.
4. Fasten actuator to bracket and bracket to engine. Attach necessary linkage
between actuator shaft and fuel control lever. Move linkage end-to-end to
confirm correct travel and adjust length if needed.
5. Connect actuator wires (use twisted pair with more than 1 twist per inch).
Actuator travel should be adjusted to assure both maximum (start fuel or rated
load) and minimum (shutdown or idle) positions.
Figure 5. Actuator Wiring
NOTE: It is beyond the scope of this manual to discuss detailed actuator
selection and installation procedures for all possible applications. Please contact
the factory for specific information concerning your application.

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4500 Electronic Engine Speed Governing System Manual SE-4097
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Engine Speed Setpoint Wiring—Analog Input
Guidelines
The APECS 4500 controller features an analog speed input for mobile or stationary
applications. To incorporate this feature, wire the analog input to an external pot (which
must be connected to a pedal). Use Figures 6 & 7 as a guide to wire the input to your
application. Potentiometer resistances of 3K–5Kare recommended.
Once the analog speed input is wired, refer to the APECS Calibration section to
configure the appropriate parameters.
If use of an idle verification switch (IVS) is desired, hook up Pin J2-5 from the controller
to the idle verification switch on the pedal. (Refer to the manufacturer’s instructions or
OEM manual.) The other side of the switch should be connected to battery voltage (see
Figure 7).
During engine operation, if the IVS switch and pedal pot do not agree, the engine will
operate at minimum speed only.
Non-potentiometric analog voltages may also be used to command set speed. The
analog voltage (0-5 volt max.) should be wired across terminals J2-12 (positive) and
J1-4 (ground).
Figure 6. Analog Input Switch
Figure 7. Analog Input Switch with IVS