EDM 760

J.P. Instruments EDM 760 User Manual

EDM-760 Quick Reference Guide

PEAK EGT

Pre-lean

the mixture

Tap LF

button

Lean the

mixture

Stop at

peak

Enrich to

peak or

100° rich of

peak

t a p S T E P b u t t o n

t a p L F b u t t o n , t h e n S T E P b u t t o n

L F

t a p S T E P b u t t o n

t a p L F b u t t o n

t a p

b o t h

S T E P a n d L F

s i m u l t a n e o u s l y

T o g g l e

i n c l u d e / e x c l u d e

p a r a m e t e r i n

i n d e x i n g

D i s p l a y s p e a k

E G T v a l u e

A U T O I N D E X :

p a r a m e t e r s

i n d e x e d

a u t o m a t i c a l l y

M A N U A L

I N D E X :

p a r a m e t e r s

i n d e x e d w h e n

S T E P i s t a p p e d

L E A N F I N D :

s t a r t s

L e a n F i n d

p r o c e d u r e

r e l e a s e b u t t o n s

r e l e a s e L F b u t t o n

h o l d L F b u t t o n

How to use LeanFind (page 13)

How to Change Modes (page 7)

EDM-760 enters Automatic indexing mode two minutes after power up

How to …

interpret CHT trends page 6 reset an alarm page 26 lean turbocharged engines page 19 set start up fuel page 29 diagnose engine problems page 23 accumulate total fuel page 30 calibrate OAT readings page 37 reset fuel used page 30 change from °F to °C page 37, 44 set fuel tank capacity page 47 dump data to a PC page 36 set K factor page 41

Note Tank size can be entered by holding in the step button upon start-up.

Specifications

FAA Approved

Indicator TSO & STC Fuel Flow Option STC

Display Size:

3 1/8 in panel mount

3.5 in. sq., 7.5 in. deep

Common Mode Range:

+ 4v, rejection > 80db

Analog Thermocouples

Response curve: All Linearized.

Resolution: 1.0 oF

Accuracy: + 1.0 oF Calibration: type K (J CHT avail.)

Operating Temperature Range:

-40 to 195 oF

Temperature Range:

EGT bar graph: variable

EGT, TIT digital: -40 to 2500 oF

CHT, OAT, IAT: -40 to 800 oF

Analog input channels:

12 Exhaust Gas Temperature (EGT) 12 Cylinder Head Temperature (CHT) 2 Turbine Inlet Temperature (TIT) 2 additional channels (either OIL, CRB or second TIT) 1 Outside Air Temperature (OAT) 1 System Bus Voltage (BAT)

Resolution and Display Range (Fuel Flow Option)

display maximum display value resolution

K factor range: 5,000 to 99,990 10

Fuel flow: Accuracy (8 to 60 GPH) 1 %

140.0 GPH at K factor 85,000 0.1 GPH

410.0 GPH at K factor 29,000 0.1 GPH 820 PPH at K factor 85,000 1 PPH 2400 PPH at K factor 29,000 1 PPH 560 LPH at K factor 85,000 1 LPH 1640 LPH at K factor 29,000 1 LPH 372 KPH at K factor 85,000 1 KPH 1088 KPH at K factor 29,000 1 KPH

Fuel Remaining: 999.9 Gal 0.1 Gal

999 Lbs., L, or Kg 1 Lb., L, or Kg

Fuel Used: 999.9 Gal. 0.1 Gal

9999 Lbs., L, or Kg 1 Lb., L, or Kg

Time to Empty: 50 hours 1 minute

Long Term Memory

Data capacity: up to 17 hours sampled every 6 seconds Recording rate: programmable, every 2 seconds to 500 seconds

Pilot’s Guide

EDM-760 TWIN

Printed in the United States of America

J.P.INSTRUMENTS

Information: P. O. Box 7033 Huntington Beach, CA 92646

3/15/2012 13:29:00 a3/p3

Factory: 3185-B Airway Avenue Costa Mesa, CA 92626

(714) 557-5434 Fax (714) 557-9840

jpinstruments.com ,

JPITech.com and BUYJPI.com

Rev L

Table of Contents

Section 1 - Introduction 1 Section 2 - Displays and Controls 4 Section 3 - Operating Procedures 11 Section 4 - Diagnosing Engine Problems 23 Fuel Flow Option Operation 28 Long Term Memory 34 Personalizing 37 Fuel Flow Option—Formats, Diagnostics 48 Section 5 - Option Connector Pin Assignments 50 Reference Reading 51 Section 6 - Technical Support 51 Limited Warranty 52 Index 53

Section 1 - Introduction

Product Features

EDM-760 Standard Instrument:

• Hands-free, automatic scanning

• Bar graph

• LeanFind mode

• Battery voltage

• Normalize view

• DIF low to high EGT spread

• Shows largest EGT variance

• Oil temperature option

• EGTs to 1°F resolution

• Shock cooling monitoring

• Outside air temperature (OAT)

option

• User selectable index rate

• Alarm “red line” limits

• Fast response probes

• Real-time serial data port

Fuel Flow Option:

• Solid-state pulse generating rotor

fuel flow transducer

• Fuel quantity measured in gallons,

kilograms, liters, or pounds

• Low fuel quantity alarm

• Low fuel time alarm

• GPS interface

• Instantaneous fuel flow rate,

• Total amount of fuel consumed,

• Total fuel remaining, and

• Time to empty at the current fuel

flow rate.

Long Term Memory:

• Records and stores data every 2 to

500 seconds

• Non-volatile memory

• Post-flight data retrieval

• Data retrieval software

• 17 hours data capacity at 6 second

sample rate

Engine Data Management

The EDM-760 Engine Data Management system is the most advanced and accurate piston engine monitoring instrument on the market. Using the latest microprocessor technology, the EDM-760 will monitor up to twenty-four critical measurements in your engines, three times a second, with a linearized thermocouple accuracy of better than 0.1 percent or 2°F.

As your built-in flight engineer, the EDM-760 is constantly “red line” checking: all critical measurements are automatically checked several times a second, regardless of the current display status. Leaning is

accomplished quickly and automatically using the LeanFind procedure.

With the EDM-760 it is now possible to have substantially more

CHT probe

EGT probe

cylinder

head

exhaust

manifold

diagnostic information available to you in a timely and usable manner.

The included data memory permits you to record all measurements for later down loading to your laptop or Palm handheld.

Benefits of Proper Mixture Control

• Improved engine efficiency • Reduced maintenance

costs

• Greater fuel economy • Reduced operating costs

• Smoother engine operation • Proper engine

temperatures

• Longer spark plug life • Reduced engine vibration

JPI Probes

Temperature information processed by the EDM-760 is captured by fast response, grounded JPI temperature probes, that accurately measure the small temperature changes—as small as 1°F—that occur during mixture adjustment.

Temperature and Mixture

In a piston engine only a small portion of the energy from combustion produces movement of the piston during the power stroke. The majority of energy passes into the exhaust pipe as hot gasses. By monitoring the temperature of these exhaust gasses you will have an indication of the quality of the combustion process. Low compression, non-uniform fuel distribution, faulty ignition, and clogged injectors diminish the efficiency of the combustion process that generates power.

From the cockpit you can adjust the fuel/air ratio by a process called leaning. Retarding the mixture control changes the fuel/air ratio and hence the resulting Exhaust Gas Temperature (EGT).

The following figure depicts the mixture and temperature relationship.

Page 2 Engine Data Management

EGT °F below peakPercent of best power

CHT °F change from

best power

Best

economy

range

Best power range

-200

-100

-300

-20

-60

-40

-80

100

Too lean

LeanRich

Full Rich

(Take-off)

Peak EGT

Leaner Mixture

Peak

Power

As the mixture is leaned, EGT rises to a peak temperature, and then drops as the mixture is further leaned. Peak power occurs at a mixture using more fuel than at peak EGT. Best economy occurs at peak EGT. Accurate leaning yields optimal engine temperatures. By being able to precisely adjust the mixture, your engines can produce either the highest fuel economy or maximum power, whichever you choose.

A single EGT gauge merely gives you an average of each cylinder’s temperature: some cylinders can be too rich, while others too lean. Variations produced by differences in fuel distribution, ignition, and compression will cause each cylinder to follow its own mixture and temperature relationship such that one cylinder will reach peak before another.

For Your Safe Flight Page 3

Section 2 - Displays and Controls

I 4 0 I I 4 5 2

S T E P L F

% M A X

1 2 3 4 5 6 T

° F L R P

3 9 0 3 6 3

E G T

C H T

E D M - 7 6 0

C H T s h o w n o n c a l i b r a t e d s c a l e

E G T b a r g r a p h r a n g e i s 8 2 5 ° F ( h a l f r e d l i n e ) t o 1 6 5 0 ° F

N o r P

i n d i c a t e s N o r m a l i z e o r P e r c e n t v i e w





T I T b a r g r a p h ,

O I L a s m i s s i n g

s e g m e n t

 



D o t i n d i c a t e s w h i c h

c y l i n d e r t e m p e r a t u r e s

a r e s h o w n i n t h e

d i g i t a l d i s p l a y



D i g i t a l t e m p e r a t u r e i n ° F o r ° C

1 2 3 4 5 6 T

E x h a u s t G a s T e m p e r a t u r e

( E G T ) i s t h e t o p

o f t h e c o l u m n

C y l i n d e r H e a d

T e m p e r a t u r e

i s s h o w n a s a

m i s s i n g b a r

3 0 0

4 0 0

5 0 0

C H T

The EDM-760 monitors engine temperatures and voltages, assists in adjusting the fuel/air mixture, and helps diagnose engine malfunctions. There are three components of the user interface:

• Analog display including cylinder number and index dot

• Digital display for numeric readouts and messages

• Two front panel operating buttons.

Displays

Analog Display

The upper half of the face of the EDM-760 is the analog display.

The following is a description of the analog display, from top to bottom. Numbers in circles refer to features in the above diagram.



Page 4 Engine Data Management

Temperature Units (°F or °C)

• °F temperatures in the digital display are in Fahrenheit

degrees.

• °C temperatures in the digital display are in Celsius degrees.

To change the display of OAT see “Pilot Programming” on page 37. To change the display of engine temperatures see “Changing the Alarm Limits” on page 44.



Cylinder Numbers and Dot Index

A row of numbers 1 through 6 and the letter T are the column labels for the analog display. The 1 through 6 are the cylinder numbers. If the TIT option is installed, the T denotes the last column is displaying Turbine Input Temperature (TIT). If the T is absent and the Oil temperature option is installed, the last column displays Oil temperature. If both TIT and Oil temperature options are installed, the last column displays TIT and the missing segment displays OIL. A round dot under the numbers 1 through 6 indicates that particular column is shown numerically in the EGT and CHT digital display.



Normalize and Percentage View Indicators

• Percentage view: when there is a P at the top of the display,

the columns indicate percent of EGT red line. Each column is composed of a stack of segments. A maximum height column depicts 100 percent of red line and a one segment-high column depicts 50 percent of red line. For example, if the red line is 1650°F, a maximum height column represents 1650°F and a one segment-high column represents half that value, or 825°F. The Percentage view permits comparison of EGTs across all cylinders. Hotter cylinders display higher columns than cooler cylinders.

• Normalize view: when there is an N at the top of the display,

the EGT columns are displayed normalized. When you change to the Normalize view, all column peaks are set to the same half-height level for trend analysis. Any changes are shown as an increase or decrease in column height. A onesegment change in column height represents a 10°F change. The Normalize view permits rapid visualization of EGT trends, rather than a percentage of red line. You may use normalize in level cruise.

To toggle between Percentage and the Normalize views, hold the LF button for three seconds. The analog display becomes half height and the

display changes to the Normalize view. Selecting the Normalize view does not affect the digital display nor alter the measurement sequence. The

For Your Safe Flight Page 5

CHT display—described later—is not affected by the Normalize or

3 0 0

4 0 0

5 0 0

C H T

Percentage view.

You may select the Normalize view in either the Manual or Automatic indexing mode. Normalize view is most helpful for engine trend monitoring of each cylinder’s operation. For example using the Normalize view during engine run-up, a fouled spark plug will appear as a higher column.

A common mistake is to be in the Normalize view and then change your power setting, causing all columns to go off scale, high or low. Set to the Percentage view before adding or reducing power. Always set Percentage View when beginning your descent.



Bar Graph EGT and CHT

Each column in the bar graph is composed of a stack of segments. The total height of each column represents the EGT and the missing segment in the column represents the CHT trend.

• In the Percentage view, the EGT and TIT (or

Oil temperature) columns’ resolutions depend on the programmed red line limits.

• CHT is displayed by a missing segment or a

single isolated lighted segment, in 25°F increments.

The CHT display is the not affected by mode or view.

Digital Display

Beneath the bar graph is the 9-segment alphanumeric display.

EGT and CHT

When the dot index is beneath a cylinder number, 1 through 6, the digital display shows the EGTs on the top (four digits for each engine) and the CHTs on the bottom (three digits for each engine). Other measurements are displayed in the digital display as described in the subsection “Measurement Indexing—without Fuel Flow Option” on page 10.

Page 6 Engine Data Management

I 4 0 I I 4 5 2

S T E P L F

% M A X

1 2 3 4 5 6 T

° F L R P

3 9 0 3 6 3

E G T

C H T

E D M - 7 6 0

3 d i g i t d i s p l a y

o f C H T

L e f t E n g i n e

4 d i g i t

d i s p l a y o f

E G T

L e f t E n g i n e

3 d i g i t d i s p l a y

o f C H T

R i g h t E n g i n e

4 d i g i t

d i s p l a y o f

E G T

R i g h t E n g i n e

1 2 3 4 5 6 T

3 0 0

4 0 0

5 0 0

C H T

C H T s h o w n o n c a l i b r a t e d s c a l e

Display Dimming

The entire display panel features automatic dimming. Allow ten seconds for the display to adjust to ambient lighting conditions.

Modes

There are three standard operating modes of the EDM-760: Automatic indexing, Manual indexing, and LeanFind. These modes will be

described in more detail beginning on page 11. Most of the time you will operate the EDM-760 in the Automatic indexing mode. When you first turn on the power the EDM-760 starts in the Manual indexing mode, but will enter the Automatic indexing mode after two minutes. The three modes affect primarily the digital display.

Automatic Indexing Mode

Just tap the LF button, then tap the STEP button. No user intervention

is required to use this mode. Each cylinder and each measurement value is automatically sequenced and shown in the digital display for a few seconds.

Manual Indexing Mode

Just tap the STEP button. Automatic Indexing stops. Each indexed

measurement is frozen in the digital display until you manually index to the next measurement by tapping the STEP button.

For Your Safe Flight Page 7

LeanFind Mode

Simply pre-lean, tap the LF button and begin leaning. The EDM-760

will assist you in finding the first cylinder to peak.

Buttons

Buttons, Front Panel

Two operating buttons control all functions of the EDM-760.

The term tap will be used to denote pressing a button momentarily. The term hold will be used to denote pressing and holding a button for five seconds or longer.

STEP Button

Located on the lower left side near the instrument face.

• In the Automatic indexing mode, tapping the STEP button will

stop indexing and change to the Manual indexing mode. Then each tap of the STEP button will display the next measurement in the sequence.

• In the LeanFind mode tapping the STEP button will terminate

the LeanFind mode and change to the Automatic indexing mode.

Secondary functions of the STEP button include:

• In the Manual indexing mode holding the STEP button will

display the previous measurements in the sequence (rapidly backwards).

• In the programming procedures, described on page 37, tapping

the STEP button will advance to the next item in the list.

• When an alarm is displayed (“Alarms” are described on page 43),

tapping the STEP button will temporarily delete that measurement from the sequence for the next ten minutes.

• When an alarm is displayed, holding the STEP button until the

word OFF appears will delete that measurement from the sequence for the remainder of the flight.

Page 8 Engine Data Management

LF Button

N: Normalize viewP: Percentage view

hold LF button

for 3 seconds

Located on the lower right side near the instrument face.

• In Automatic or Manual indexing modes, tapping the LF

button will change to the LeanFind mode.

• In Automatic or Manual indexing modes holding the LF

button for three seconds will toggle between Percentage and Normalize views.

• In the LF mode holding the LF button after peak EGT is

found will display peak EGT.

• In the LF mode tapping the LF button twice will mark a data

record in memory.

Secondary functions of the LF button include:

• In the pilot programming procedure, holding or tapping the

LF button is used to increment or decrement parameter values and toggle between yes and no answers to questions.

STEP and LF Buttons

• Holding both the STEP and LF buttons simultaneously for

five seconds changes to the pilot programming procedure.

• Holding both the STEP and LF buttons simultaneously for

five seconds after tapping LF but before beginning to lean will toggle between Rich of Peak and Lean of Peak

• Tapping both the STEP and LF buttons simultaneously in

Manual indexing mode toggles to include or exclude the displayed measurement from the Automatic indexing mode. It has no affect on the displayed measurements in the Manual indexing mode.

For Your Safe Flight Page 9

Measurement Indexing—without Fuel Flow Option

The EDM-760 steps through the engine measurements in a specific sequence. Listed below is the indexing sequence, measurement description and example of the digital display.

Measurement Example Comments

Voltage, System Bus Outside Air

Temperature

I4.2 8I BAT OAT

Battery voltage and OAT °F or °C

Difference between hottest and coolest EGT

EGT, CHT

TIT, Turbine Inlet

Temperature

Oil Temperature

TIT #2 Second Turbine

Inlet Temperature

80 EGT 52 DIF DIF

I340 I430 376 385

I370 I450 TIT TIT

I 7 7 I80 OIL OIL

I450 I460 T I2 T I2

Dot indicates most widely deviating cylinder

EGT, left, CHT, right. Dot indicates cylinder

Only one of these three options may be installed in the aircraft

Carburetor Temperature

20 25 CRB CRB

Page 10 Engine Data Management

Shock Cooling

-30

-40

Dot indicates fastest cooling cylinder

CLD CLD

The display will pause at each measurement for four seconds in the Automatic indexing mode. (The four second indexing rate can be changed. See “Pilot Programming” on page 37.) In the Manual indexing mode, tap the STEP button to advance to next measurement. Only the measurements for the options that are installed will be displayed; uninstalled measurements will not appear.

Section 3 - Operating Procedures

Diagnostic Testing on Startup and During Flight

When your EDM-760 is first turned on, all digits light up for a few seconds, permitting you to check for non-functional segments. Then each column is self-tested in sequence while the EDM-760 tests internal components, calibration and integrity of the probes. If a problem is found, it will be displayed as OPEN PRB or CAL ERR, followed by the name of the probe or channel. During flight, probes are constantly checked for inconsistent or intermittent signals. A faulty channel or probe encountered during start-up or during flight will be deleted from the sequence, producing a missing column or blank digital data.

Modes

The EDM-760 has three different operating modes: Automatic indexing, Manual indexing and LeanFind. When you first turn on the power the

EDM-760 starts in the Manual indexing mode, but will enter the Automatic indexing mode after a few minutes. The Automatic indexing mode provides you with engine monitoring information for the majority of flight conditions. To adjust the mixture, use the LeanFind mode. And to display specific measurements, use the Manual indexing mode. In both the Automatic and Manual indexing modes the analog display shows a bar graph of EGT and CHT for each cylinder and the TIT, if installed (or Oil temperature, if it is installed and TIT is not installed).

For Your Safe Flight Page 11

Automatic Indexing Mode

Just tap the LF button, then tap the STEP button. No user intervention is required to use this mode. In the Automatic indexing mode the EDM760 displays the measurement sequence at a user-selected indexing rate (see “Personalizing” on page 37).

Individual measurements can be excluded from the Automatic indexing mode: tap STEP to enter the Manual indexing mode. Tap STEP to index to the measurement you want to exclude. Then tap both the STEP and LF buttons simultaneously. Excluded measurements display a decimal point before the measurement name.

For example:

↓

Included I84 OIL Excluded I84 OIL

Tapping the STEP and LF buttons simultaneously will toggle back and

forth between include and exclude.

• You can program whether every time you turn on the EDM-760, it

will remember which measurements were excluded or defaults to none excluded. See on page 45.

• All installed measurements are always displayed in the Manual

indexing mode. Exclusion only applies to the Automatic indexing mode.

• All measurements are checked for alarm conditions every second

regardless of their included or excluded status.

Manual Indexing Mode

Just tap the STEP button. Use the Manual indexing mode when you want to monitor one specific measurement such as shock cooling during descent, or a particular cylinder temperature during climbs. To change to the Manual indexing mode, tap the STEP button once. Subsequent taps will index the digital display through the measurement sequence (see “Measurement Indexing—without Fuel Flow Option” on page 10). To exit the Manual indexing mode and return to the Automatic indexing mode, either tap the LF button and then tap the STEP button (see “How

Page 12 Engine Data Management

to Change Views” in the front of this manual). You may disable the Automatic indexing mode. See “Personalizing” on page 37.

LeanFind Mode—Leaning Rich of Peak

• JPI’s EDM-760 provides two methods of leaning: lean

rich of peak (LEAN R) or lean of peak (LEAN L). The

standard method is to lean about 20° rich of peak. With the advent of GAMI injectors it is now possible to set the mixture lean of peak—saving fuel and running the engine cooler. Teledyne Continental recommends lean of peak for the Malibu. This manual primarily describes the rich of peak method, and provides the procedure for the lean of peak method. The factory default method is set to rich of peak, but you can change this to lean of peak. See Changing the Alarm Limits

Procedure on page 45.

Simply pre-lean, tap the LF button and begin leaning. Upon reaching cruise configuration, you will use the LeanFind mode to identify the first cylinder to reach peak EGT.

A more detailed explanation of the LeanFind procedure follows this stepby-step procedure.

For Your Safe Flight Page 13

EGT °F below

peak

Percent of best

power

CHT °F change from

best power

Best

power

range

-100

-50

-20

-60

-40

100

Too lean

LeanRich

Full Rich

(Take-off)

First

cylinder to

peak. Use for

Rich of Peak

leaning

Last

cylinder to

peak. Use for

Lean of Peak

leaning with GAMI injectors

Peak Power

Best

economy

range

GAMI

spread

Page 14 Engine Data Management

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