Product Manual 02008

(Revision NEW)
Original Instructions

Fuel Limiter
Reverse Acting Model 8272-789

Installation and Operation Manual

 This is the safety alert symbol. It is used to alert you to potential personal
injury hazards. Obey all safety messages that follow this symbol to avoid
possible injury or death.
 DANGER—Indicates a hazardous situation which, if not avoided, will result in death
or serious injury.
DEFINITIONS  WARNING—Indicates a hazardous situation which, if not avoided, could result in
death or serious injury.
 CAUTION—Indicates a hazardous situation which, if not avoided, could result in
minor or moderate injury.
 NOTICE—Indicates a hazard that could result in property damage only (including
damage to the control).
 IMPORTANT—Designates an operating tip or maintenance suggestion.

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.

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.

This publication may have been revised or updated since this copy was produced. To verify that
you have the latest revision, be sure to check the publications page on the Woodward website:
www.woodward.com/publications
The current revision and distribution restriction of all publications are shown in manual 26311.

The latest version of most publications is available on the publications page. If your publication is
not there, please contact your customer service representative to get the latest copy.

Any unauthorized modifications to or use of this equipment outside its specified mechanical,
electrical, or other operating limits may cause personal injury and/or property damage, including
damage to the equipment. Any such unauthorized modifications: (i) constitute "misuse" and/or
"negligence" within the meaning of the product warranty thereby excluding warranty coverage
for any resulting damage, and (ii) invalidate product certifications or listings.

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.

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.

Woodward reserves the right to update any portion of this publication at any time. Information provided by Woodward is
believed to be correct and reliable. However, no responsibility is assumed by Woodward unless otherwise expressly
undertaken.
Copyright © Woodward 1992
All Rights Reserved
Manual 02008 Reverse Acting Fuel Limiter

Contents

CHAPTER 1. INTRODUCTION......................................................................... 1 
CHAPTER 2. DESCRIPTION OF OPERATION ................................................... 2 
CHAPTER 3. INSTALLATION.......................................................................... 4 
Unpacking ...............................................................................................................4 
Installation ..............................................................................................................4 
Electrical Connections ............................................................................................6 
CHAPTER 4. LIMITER ADJUSTMENT AND TROUBLESHOOTING ....................... 7 
Introduction .............................................................................................................7 
Troubleshooting Procedure ....................................................................................7 
Limiter Adjustment ..................................................................................................8 
CHAPTER 5. PRODUCT SUPPORT AND SERVICE OPTIONS ........................... 10 
Product Support Options ......................................................................................10 
Product Service Options .......................................................................................10 
Returning Equipment for Repair ...........................................................................11 
Replacement Parts ...............................................................................................11 
Engineering Services............................................................................................12 
Contacting Woodward’s Support Organization ....................................................12 
Technical Assistance ............................................................................................13 

Illustrations and Tables

Figure 2-1. Block Diagram of 8272-789 Fuel Limiter .............................................3 

Figure 3-1. Outline Drawing of Fuel Limiter 8272-789 ...........................................5 
Figure 3-2. Plant Wiring Diagram ...........................................................................6 
Figure 4-1. Limiter Levels and Slopes ....................................................................8 

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Manual 02008 Reverse Acting Fuel Limiter

Chapter 1.
Introduction

A fuel limiter is an electronic device that limits the maximum drive signal to an
actuator. The amount of drive current reaching the actuator is determined by the
input to the limiter.

The 1–5 Vdc input signal may be from a manifold-pressure sensor, a load
sensor, or from a sensor that monitors some other process-related parameter.
The fuel limiter also receives an actuator signal from a reverse acting 2301A
control. (200 mA signal is minimum fuel, 0 mA is maximum fuel.) This signal is
called the "control signal" to the limiter.

Fuel limiters are commonly used to reduce diesel emissions during starting and
to provide more efficient engine load or speed increases.

The start-fuel-limiting application reduces smoke by limiting the maximum

actuator signal that reaches an actuator during starting.

The fuel limiter consists of a printed-circuit board enclosed in a sheet-metal box.

All adjustments and connections for external wiring are accessible from the front
of the control.

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Reverse Acting Fuel Limiter Manual 02008

Chapter 2.
Description of Operation

Figure 2-1 is a block diagram of the 8272-789 fuel limiter. The limiter is designed
to provide a maximum actuator signal on a schedule determined by the setting of
the slope and level potentiometers for Limiter 1 and Limiter 2.

In operation the limiter modifies a 1–5 volt signal that is proportional to inlet-
manifold pressure. This modified signal is then used by the limiter to generate a
signal that is reflective of the position on the slope. A modified control-actuator
signal is compared with this signal and the highest signal is generated by the
current driver to provide a 40–160 mA signal for the actuator on the engine.

The limiter prevents over fueling the engine when the inlet manifold pressure is
too low to properly mix a certain amount of fuel. This operation will prevent
unnecessary smoke and will also provide more efficient engine load or speed
increases.

If the contacts between terminal 12 and 13 are closed the fuel limiter functions
are both disabled and the actuator signal will always exactly track the control
signal. Should these contacts open the limiter will follow the highest signal from
either the speed control or from the limiter schedules.

If the contacts between 14 and 13 or 14 and 15 are closed that respective fuel
limiter slope will be disabled and the remaining slope will still be limiting the
actuator based on the 1-5 Vdc input. These contacts should only be closed to
disable one fuel limiter schedule or the other. Close the contacts between 12 and
13 to disable both limiters at the same time.

If the circuit between terminals 12 and 13 is closed the contacts

between terminals 14 and 15 and 14 and 13 must be open. If either of
the slope contacts (14–15 or 14–13) are closed at the same time as
terminals 12–13 the limiter circuits maybe stressed and/or over
heated.

The fuel limiter, when active, limits the drive-signal current to the
actuator. The actual position of the fuel-rack may vary, depending on
temperature, actuator calibration, linkage wear, or other factors.

The fuel limiter must be powered up at all times the engine is running. Should the
limiter lose power, the actuator signal will be interrupted. With no control signal
the electric side of the reverse acting actuator will call for maximum fuel.

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Manual 02008 Reverse Acting Fuel Limiter

Figure 2-1. Block Diagram of 8272-789 Fuel Limiter

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Chapter 3.
Installation

Unpacking
The Fuel Limiter is shipped in a foam protected box. Should any damage be
discovered while unpacking the limiter, immediately contact the shipper and
Woodward.

The limiter is packaged in a special antistatic protective bag. Leave the control in
its protective bag until ready to install. An antistatic bag should always be used
when the control box is moved or replaced.

Installation
Power Requirements
The fuel limiter requires a voltage source of 20 to 40 Vdc for operating power. If a
battery is used for operating power, provide a battery charger to maintain a
stable dc supply voltage.

Do not exceed the allowable range for the supply voltage. Over 40
volts will damage the control. Severe voltage spikes also can
damage electronic controls.

Location Considerations and Mounting the Control

The fuel limiter is designed to operate within a temperature range of –40 to +160
°F (–40 to +71 °C). The unit may be mounted in any position, provided adequate
ventilation is allowed for cooling.

The fuel limiter is shipped with a throwaway cover on the bottom of the box.
Detach and discard the cover, being careful not to touch the printed-circuit board.

Install the box in an off-engine location. Consider the needs for adequate
ventilation, space for servicing and repair, proximity to auxiliary electrical
equipment, and to extreme heat or vibration.

The control box is open on the bottom. Do not attempt to seal the unit to the
installation surface as this would disrupt expected air movement and might cause
over heating of the unit. Additional air circulation or cooling will not be required.

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Manual 02008 Reverse Acting Fuel Limiter

Figure 3-1. Outline Drawing of Fuel Limiter 8272-789

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Reverse Acting Fuel Limiter Manual 02008

Electrical Connections
The plant wiring diagram (Figure 3-2) shows all external wiring connections
needed for installation. Be sure to follow all shielding requirements.

Shielded Wiring
All shielded cable must be twisted-conductor pairs. Do not attempt to tin (solder)
the braided shield. See the plant wiring diagram for shield requirement. Connect
shield to system ground (chassis) at one point at the limiter end only. The end
away from the limiter must be left unconnected. Do not run shielded lines in a
conduit with high-current carrying cables.

Shields on the wires to the actuator and on the input from the manifold pressure
sensor should be grounded at the limiter. The shield on the wires from the control
to the limiter should be grounded at the control and left open at the limiter.

Ground shields at one end only. Do not ground at both ends.

Figure 3-2. Plant Wiring Diagram

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Manual 02008 Reverse Acting Fuel Limiter

Chapter 4.
Limiter Adjustment and Troubleshooting

Introduction
Fuel Limiter schedules are adjustable, but adjustment is not recommended in a
field application. The engine manufacturer usually adjusts the individual unit to
match an individual engine, then seals the adjustments to prevent movement.

This chapter provides guidelines for adjustment in cases where the limiter has
been replaced or where application of the engine has changed and adjustment is
necessary.

Troubleshooting Procedure
The solid-state circuitry in the limiter should not shift limiting schedules during the
life of the limiter. Should an engine that has been operating acceptably start to
smoke or exhibit other indications of limiter problems first check the manifold
pressure sensor, the turbo, the waste gate, the linkage from the actuator to the
fuel control, the wiring (pay particular attention to the shielding), and the condition
of the engine itself.

In most installations the limiter can be bypassed and the actuator signal from the
control run directly to the actuator. This may help determine if the limiter is at
fault.

Operational Test
1. Remove the limiter from the control system. Connect a 35 ohm, 25 watt
resistor between the actuator output terminals 5 (+) and 6 (–). (The resistor is
used to simulate the actuator. Connect an ammeter capable of reading
0–200 mA across terminals 5 (+) and 6 (–).

2. Connect a 24 Vdc power supply, minimum capacity of 1.5 amps, to terminals

1 (+) and 2 (–).

3. Connect a variable 1–5 Vdc power supply to terminals 3 (+) and 4 (–).

4. Connect a variable 1–5 Vdc power supply to terminals 9 (+) and 10 (–).

5. Jumper terminal 12 to terminal 13. (There must be no connection between

terminals 13, 14, and 15.)

6. As the control signal power supply across terminals 3 and 4 is varied an

identical signal should be read across terminals 5 and 6.

7. Remove the jumper between terminals 12 and 13. Set the input at terminals
3 and 4 at maximum (6 Vdc or 160 mA). Set the input of the variable power
supply across terminals 9 and 10 at 5 Vdc.

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Reverse Acting Fuel Limiter Manual 02008
8. Observe the voltage across terminals 5 and 6 increase as the input to
terminals 9 and 10 is decreased. (The accompanying graph shows relative
output in mA for given limiter voltage inputs. Notice that the output decreases
as the manifold signal increases. This is correct for a reverse acting control
system.) The graph shows the factory setting for the limiter. The engine
manufacturer may have changed this setting and the user cannot expect the
limiter output to exactly follow the graph.

9. If the troubleshooting observations are as outlined the operator can assume

the limiter is operating correctly . Be careful when replacing the limiter in the
control system to attach all wiring according to the plant wiring diagram and
to complete all shielding requirements.

Figure 4-1. Limiter Levels and Slopes

Limiter Adjustment
The desired limiter slopes must be determined before setting up the limiter. Until
the starting and ending level of each slope is known a new limiter cannot be
adjusted. (Most actuators are almost exactly linear (the actuator output position
moves in direct proportion to the magnitude of the control signal). However,
linkage between the actuator and the fuel control can modify this linearity. If the
adjustment of the fuel level (power output) of the engine is not exactly
proportional to the control signal to the actuator the levels and slopes of the
limiter may have to be modified.

1. Set up the limiter as described in steps 1, 2, 3, and 4 above.

2. Set the voltage input to terminals 3 and 4 to 0 Vdc.

3. Close contacts between terminals 14 and 15 to deactivate the second slope.

Open contacts between 12–13 and 13–14.

4. Set both Level potentiometers fully clockwise (CW).

5. Set both Slope potentiometers fully counterclockwise (CCW).

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Manual 02008 Reverse Acting Fuel Limiter
6. Set the variable supply for the minimum manifold signal at terminals 9 and
10. Set the variable supply at Terminals 3 and 4 for the maximum signal (6
volts).

7. Adjust the Level 1 potentiometer CCW until the actuator signal at terminals 5
and 6 reaches the voltage for maximum limiting.

8. Set the supply at terminals 9 and 10 for the desired level for the end of Slope
1 and start of Slope 2.

9. Adjust the Slope 1 potentiometer CW until the actuator output from the limiter
reaches the desired level for this position on your graph.

10. Check the output of limiter for desired range. Repeat steps 6 through 9 until
the output of the limiter matches your graph.

11. Open contacts between terminals 14 and 15 and close contacts between 13
and 14 to activate the second slope and deactivate the first slope.

12. Adjust the Level 2 potentiometer CCW until actuator voltage reaches the
same level as in step 9.

13. Adjust the supply at terminals 9 and 10 for the desired level at maximum
manifold pressure.

14. Adjust the Slope 2 potentiometer CW until the actuator output reaches the
level as shown on your graph.

15. Check output of the limiter for desired range. Repeat steps 11 through 14
until the output of the limiter matches your graph.

16. Open the contacts between terminals 13 and 14. Adjust supply at terminals 9
and 10 from minimum to maximum (1–5 Vdc). Measure the output at
terminals 5 and 6. The voltage should follow the desired limiting schedule
without any "bumps" in the output. If there are noticeable steps in this output
repeat steps 6 through 15.

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Reverse Acting Fuel Limiter Manual 02008

Chapter 5.
Product Support and Service Options

Product Support Options

If you are experiencing problems with the installation, or unsatisfactory
performance of a Woodward product, the following options are available:
1. Consult the troubleshooting guide in the manual.
2. Contact the OE Manufacturer or Packager of your system.
3. Contact the Woodward Business Partner serving your area.
4. Contact Woodward technical assistance via email
(EngineHelpDesk@Woodward.com) with detailed information on the
product, application, and symptoms. Your email will be forwarded to an
appropriate expert on the product and application to respond by telephone
or return email.
5. If the issue cannot be resolved, you can select a further course of action to
pursue based on the available services listed in this chapter.

OEM or Packager Support: Many Woodward controls and control devices are
installed into the equipment system and programmed by an Original Equipment
Manufacturer (OEM) or Equipment Packager at their factory. In some cases, the
programming is password-protected by the OEM or packager, and they are the best
source for product service and support. Warranty service for Woodward products
shipped with an equipment system should also be handled through the OEM or
Packager. Please review your equipment system documentation for details.

Woodward Business Partner Support: Woodward works with and supports a

global network of independent business partners whose mission is to serve the
users of Woodward controls, as described here:
 A Full-Service Distributor has the primary responsibility for sales, service,
system integration solutions, technical desk support, and aftermarket
marketing of standard Woodward products within a specific geographic area
and market segment.
 An Authorized Independent Service Facility (AISF) provides authorized
service that includes repairs, repair parts, and warranty service on
Woodward's behalf. Service (not new unit sales) is an AISF's primary
mission.
 A Recognized Engine Retrofitter (RER) is an independent company that
does retrofits and upgrades on reciprocating gas engines and dual-fuel
conversions, and can provide the full line of Woodward systems and
components for the retrofits and overhauls, emission compliance upgrades,
long term service contracts, emergency repairs, etc.

A current list of Woodward Business Partners is available at

www.woodward.com/directory.

Product Service Options

Depending on the type of product, the following options for servicing Woodward
products may be available through your local Full-Service Distributor or the OEM
or Packager of the equipment system.
 Replacement/Exchange (24-hour service)
 Flat Rate Repair
 Flat Rate Remanufacture

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Manual 02008 Reverse Acting Fuel Limiter
Replacement/Exchange: Replacement/Exchange is a premium program
designed for the user who is in need of immediate service. It allows you to
request and receive a like-new replacement unit in minimum time (usually within
24 hours of the request), providing a suitable unit is available at the time of the
request, thereby minimizing costly downtime.

This option allows you to call your Full-Service Distributor in the event of an
unexpected outage, or in advance of a scheduled outage, to request a
replacement control unit. If the unit is available at the time of the call, it can
usually be shipped out within 24 hours. You replace your field control unit with
the like-new replacement and return the field unit to the Full-Service Distributor.

Flat Rate Repair: Flat Rate Repair is available for many of the standard
mechanical products and some of the electronic products in the field. This
program offers you repair service for your products with the advantage of
knowing in advance what the cost will be.

Flat Rate Remanufacture: Flat Rate Remanufacture is very similar to the Flat
Rate Repair option, with the exception that the unit will be returned to you in “like-
new” condition. This option is applicable to mechanical products only.

Returning Equipment for Repair

If a control (or any part of an electronic control) is to be returned for repair,
please contact your Full-Service Distributor in advance to obtain Return
Authorization and shipping instructions.

When shipping the item(s), attach a tag with the following information:
 return number;
 name and location where the control is installed;
 name and phone number of contact person;
 complete Woodward part number(s) and serial number(s);
 description of the problem;
 instructions describing the desired type of repair.

Packing a Control
Use the following materials when returning a complete control:
 protective caps on any connectors;
 antistatic protective bags on all electronic modules;
 packing materials that will not damage the surface of the unit;
 at least 100 mm (4 inches) of tightly packed, industry-approved packing
material;
 a packing carton with double walls;
 a strong tape around the outside of the carton for increased strength.

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.

Replacement Parts
When ordering replacement parts for controls, include the following information:
 the part number(s) (XXXX-XXXX) that is on the enclosure nameplate;
 the unit serial number, which is also on the nameplate.

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 Reverse Acting Fuel Limiter Manual 02008

Engineering Services
Woodward’s Full-Service Distributors offer various Engineering Services for our
products. For these services, you can contact the Distributor by telephone or by
email.
 Technical Support
 Product Training
 Field Service

Technical Support is available from your equipment system supplier, your local
Full-Service Distributor, or from many of Woodward’s worldwide locations,
depending upon the product and application. This service can assist you with
technical questions or problem solving during the normal business hours of the
Woodward location you contact.

Product Training is available as standard classes at many Distributor locations.

Customized classes are also available, which can be tailored to your needs and
held at one of our Distributor locations or at your site. This training, conducted by
experienced personnel, will assure that you will be able to maintain system
reliability and availability.

Field Service engineering on-site support is available, depending on the product

and location, from one of our Full-Service Distributors. The field engineers are
experienced both on Woodward products as well as on much of the non-
Woodward equipment with which our products interface.

For information on these services, please contact one of the Full-Service

Distributors listed at www.woodward.com/directory.

Contacting Woodward’s Support Organization

For the name of your nearest Woodward Full-Service Distributor or service
facility, please consult our worldwide directory published at
www.woodward.com/directory.

You can also contact the Woodward Customer Service Department at one of the
following Woodward facilities to obtain the address and phone number of the
nearest facility at which you can obtain information and service.

Products Used In Products Used In Products Used In

Electrical Power Systems Engine Systems Industrial Turbomachinery
Systems
Facility---------------- Phone Number Facility---------------- Phone Number Facility---------------- Phone Number
Brazil ------------- +55 (19) 3708 4800 Brazil ------------- +55 (19) 3708 4800 Brazil ------------- +55 (19) 3708 4800
China ----------- +86 (512) 6762 6727 China ----------- +86 (512) 6762 6727 China ----------- +86 (512) 6762 6727
Germany: Germany------- +49 (711) 78954-510 India --------------- +91 (129) 4097100
Kempen ---- +49 (0) 21 52 14 51 India --------------- +91 (129) 4097100 Japan -------------- +81 (43) 213-2191
Stuttgart-- +49 (711) 78954-510 Japan -------------- +81 (43) 213-2191 Korea -------------- +82 (51) 636-7080
India --------------- +91 (129) 4097100 Korea -------------- +82 (51) 636-7080 The Netherlands - +31 (23) 5661111
Japan -------------- +81 (43) 213-2191 The Netherlands - +31 (23) 5661111 Poland--------------- +48 12 295 13 00
Korea -------------- +82 (51) 636-7080 United States ---- +1 (970) 482-5811 United States ---- +1 (970) 482-5811
Poland--------------- +48 12 295 13 00
United States ---- +1 (970) 482-5811

For the most current product support and contact information, please visit our
website directory at www.woodward.com/directory.

12 Woodward
 Manual 02008 Reverse Acting Fuel Limiter

Technical Assistance
If you need to contact technical assistance, you will need to provide the following information.
Please write it down here before contacting the Engine OEM, the Packager, a Woodward
Business Partner, or the Woodward factory:

General
Your Name

Site Location

Phone Number

Fax Number

Prime Mover Information

Manufacturer

Engine Model Number

Number of Cylinders
Type of Fuel (gas, gaseous, diesel,
dual-fuel, etc.)
Power Output Rating
Application (power generation, marine,
etc.)
Control/Governor Information
Control/Governor #1

Woodward Part Number & Rev. Letter

Control Description or Governor Type

Serial Number

Control/Governor #2

Woodward Part Number & Rev. Letter

Control Description or Governor Type

Serial Number

Control/Governor #3

Woodward Part Number & Rev. Letter

Control Description or Governor Type

Serial Number

Symptoms
Description

If you have an electronic or programmable control, please have the adjustment setting positions or
the menu settings written down and with you at the time of the call.

Woodward 13
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Please reference publication 02008.

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Email and Website—www.woodward.com

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as well as authorized distributors and other authorized service and sales facilities throughout the world.
Complete address / phone / fax / email information for all locations is available on our website.

2012/9/Colorado