Alcor Egt probe User manual

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Web site: www.alcorinc.com

E-Mail: [email protected]

PN 59180

REV. G, 01/08

FAA-PMA/STC SA 522

SW: This product is FAA

approved for installation

on ALL piston engine

aircraft. After installation

of complete system,

return aircraft to service

via Form 337 referenc-

ing STC SA 522 SW.

This is not required for

replacement parts. All

piston powered aircraft,

regardless of make, are

covered by this STC.

– 4 –

EGT Probe

Installation Instructions

FAA/PMA Approved

WARRANTY INFORMATION

www.alcorinc.com

Alcor©, Inc. warrants all parts in all new Alcor©, Inc. products to be

free from defects in material and workmanship under normal use and under

the following conditions: Alcor©, Inc.’s obligation under this warranty is limited

to the repair or exchange of any defective part, if the part is returned and return

shipping prepaid, within FIVE YEARS of the date of manufacture for grounded

thermocouples and within ONE YEAR of the date of manufacture for

ungrounded thermocouples.

Alcor©, Inc. is not responsible for any service charges, including removal and

reinstallation costs, or any other consequential damages. This warranty is

void as to any product damaged as a result of misuse, accident, negligence,

unauthorized repairs or handling in transit. If the Alcor©, Inc. product's serial

number or inspection date label has been altered, the warranty is void.

Questions concerning all Alcor©, Inc.’s products should be directed

to Customer Support at 1-800-FLI-SAFE (1-800-354-7233) or email:

[email protected].

GENERAL INFORMATION

When replacing a thermocouple ensure replacement is same type as one removed by

ensuring part number/wire colors match. If stagger does not match use stagger

adapter P/N 42523. In a new installation, make sure the location on a single probe

(thermocouple) Exhaust Gas Temperature system is in the exhaust pipe of the cylin-

der that is leanest during full throttle. Particularly in carbureted engines, the leanest

cylinder can change when throttle, altitude, carburetor heat, and/or ambient air temper-

ature changes. The leanest cylinder is the one that reaches peak first when leaning

from full rich, which is sometimes the cylinder with the highest EGT. Additional informa-

tion on mixture management can be found in

Alcor's

®publication EGT Combustion

Analysis in a Nutshell and Lycoming Service Bulletin 1094D, and Continental Service

Bulletin M89-18. The probe should be located a minimum of 2 inches from the cylinder

exhaust port flange (5 inches for highly supercharged engines) in an area free from

weld beads or pipe irregularities. If the pipe has a longitudinal weld bead, orient the

clamp so that the bead does not interfere with flush fit of shoulder of flange at base of

probe tip (gas seal). Determine the location that will allow probe and wire to be free

from interference with spark plugs, baffling, cowling, exhaust and other components.

For screw-in type

Alcor

®probes use weld boss, P/N 28113 located the same distance

as clamp style probes or 3-5 inches from the turbocharger inlet in Turbine Inlet

Temperature sensing applications. All work to be done in accordance with FAA,

Advisory Circular 43.13-1B or later revision.

INSTALLATION, CLAMP TYPE

1. For new installations, carefully drill a hole at selected location using a #31 (0.120

inch/3.05mm) or #32 (0.116 inch/2.95mm) drill. If available, carefully ream hole using

#30 (0.1285 inch/3.26mm) drill. The correct hole size and alignment assures a press

fit of probe element shoulder to prevent exhaust gas leakage.

2. Open clamp and place around exaust pipe ensuring correct orientation of clamp tight-

ening screw. Place probe tip into hole and tighten clamp to remove looseness.

3. While probe element is perpendicular to exhaust carefully push and rotate probe to

fully seat element shoulder to exhaust pipe. If necessary use a small wooden dowel

and light hammer or other suitable tool to lightly tap clamp at junction of probe body

to seat probe shoulder.

4. Torque clamp to 30-35 inch pounds and cut off excess clamp and deburr. To ensure

clamp does not loosen during operation it may be safety wired from the end of slot-

ted clamp tab to body of probe or slot in screw may be safety wired to screw hous-

ing.

5. Slide fiberglass insulation sleeve over lead. Connect instrument lead to probe lead

with screws and nuts ensuring correct stagger/color combinations. Slide sleeve over

lead connection and secure with nylon ties.

6. Allow enough slack in probe lead to provide a finger-sized loop (see Figure 1) to

minimize strain on wire and secure remainder of lead to engine/airframe away from

exhaust pipe.

INSTALLATION, SCREW-IN TYPE

1. For new installations, carefully drill a hole at selected location using a #30 drill. Insert

probe into weld boss and hand tighten. Insert probe tip into drilled hole and tack

weld boss. Remove probe and weld boss to exhaust pipe.

2. Drill a .125 inch hole through the exhaust pipe at the center of the boss taking care

not to damage internal threads in boss.

3. Insert element into exhaust no deeper than .75 inch (see Figure 2).OPTIONAL- lubri-

cate probe threads with high temperature lubricant (2000°F)

4. Tighten probe nut finger tight, then with appropriate sized wrench tighten an addi-

tional 3/4 turn or till snugly locked in place.

Follow steps 5 and 6 above to complete installation.

FREQUENTLY ASKED

QUESTIONS

On a new single probe installa-

tion, which cylinder do I install

the thermocouple on?

This would be the cylinder where

the temperature peaks first while

leaning. Not all engines, even of the

same make and model, will peak the

same due to differences in internal

airflow characteristics, carburetion,

injection, etc. A worst case scenario

would be installing the probe on the

richest running cylinder (peaks last)

where lean misfire would be

reached before peak while leaning.

I installed a new probe and the

meter is still dead or went dead

again after being in operation for

awhile?

First make sure that the correct type

of probe was installed by verifying

color code matches lead and meter

(Type K, Red/Yellow, or Type E,

Red/Brown). If that checks all right

then disconnect the lead from the

meter and measure the loop resist-

ance of the lead and probe and

compare it with the value marked on

– 2 – – 3 –

NOTE: This is typically the recommended depth of

insertion for all

Alcor

®thermocouples.

Alcor

®P/N Type Color Resistance @ 70°F Millivolts at 1550-1650°F Weight Size

All Clamp K Red/Yellow .6 -1.0 ohm 34.12 - 36.36 mV .12 lbs 3.25 max dia.

All Screw-in K Red/Yellow .6 -1.0 ohm 34.12 - 36.36 mV .12 lbs call

All Clamp E Red/Brown .7 -1.0 ohm 63.04 - 67.33 mV .12 lbs 3.25 max dia.

All Screw-in E Red/Brown .8 -1.1 ohms 63.04 - 67.33 mV .12 lbs call

the meter label. If the value is approximately the same then the problem is most like-

ly the calibration potentiometer or the movement in the meter. The old probe removed

is probably good! Call

Alcor

for repair of meter.

Is there any way I can test a thermocouple without expensive equipment?

Yes, by using an

ALCAL

2000

EGT/CHT System Tester. If not available then meas-

ure the loop resistance (see resistance table) of the probe with a digital multi-meter, if

available. While viewing display, move probe wire to detect internal wire breaks. If the

reading is steady then the probe is probably good. When heated to just turning red,

the temperature is about 1550-1650°F.

RESISTANCE AND WEIGHT ARE APPROXIMATE

Figure 2. Welded Boss Type

INCORRECT (COCKED)

INCORRECT

(HOLE TOO SMALL)

CORRECT (PRESS FIT)

Ideal probe location for minimum

interference with welded seam

slack loop

lead too tight

.75"

Typical probes shown, type may vary

Weld Boss 28113

300 Breesport

San Antonio, Texas 78216

Phone 210/349/6491

Fax 210/308/8536

Toll free 800/354/7233

Figure1. Welded Boss Type