Thermocouple – L.B. White I-17 Infraconic User Manual

Page 18

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18

LEAD END OF THERMOCOUPLE

THERMOFUSE

5/16"

COVER

UPPER NUT

THERMOCOUPLE
LEAD

COVER

LOWER NUT

THERMOCOUPLE INSTALLED

UPPER RETAINING NUT

KEY HOLE SLOT

COVER

THERMOCOUPLE INSTALLED

INJECTOR TUBE

THERMOCOUPLE BODY

RETAINING NUT

COVER

THERMOCOUPLE TIP
LOCATION HOLE IN PLATE

1/2 IN TO 9/16 IN

FINISHED

THERMOCOUPLE

POSITION

1. Loosen the thermocouple connector nut at the safety

control valve. See Fig. 23.

2. L o o s e n t h e s c r ew s e c u r i n g t h e c l i p h o l d i n g t h e

thermocouple’s auto reset temperature switch to the air
housing. See Fig. 23.

3. Loosen upper retaining nut on thermocouple.

See Fig. 24.

4. Remove the thermocouple, with nuts and cover, from the

heater.

5. Position the thermocouple cover and nuts onto the

replacement thermocouple as shown in Fig. 25 Use the
cover from the original thermocouple and the nuts
supplied with the replacement.

6. Angle the thermocouple slightly so its tip and lower nut

pass through the keyhole slot. The tip must be located
within the thermocouple location hole of the burner plate.
Pull up on the thermocouple lead so the lower nut is tight
against the inside of the heater housing. Tighten upper
nut against the cover and housing. See Fig. 26.

7. The installed finished position of the thermocouple is 1/2

to 9/16 inch from the top edge of thermocouple to the
heater housing. See Fig. 26.

8. Thread the nut on thermocouple into gas control valve.

Tighten finger tight and snug in place. Position the
thermocouple’s auto reset switch under the retaining clip
and tighten the screw. See Fig.23.

FIG. 23

FIG. 24

FIG. 25

FIG. 26

TESTING THE THERMOCOUPLE

The thermocouple includes an auto reset temperature
activated switch. See Fig.23. The switch will open the
thermocouple circuit and shut off the safety valve if the
temperature at the air housing increases abnormally. To
test the thermocouple proceed as follows:

-- Remove the thermocouple from the heater

. -- Connect an ohm meter between the thermocouple

contact nut and tip.

-- A reading of less than 1 ohm is acceptable. A reading

showing overload or infinite resistance indicates an
open auto reset.

-- If open, allow the thermocouple to cool for 5 minutes.

Retest the thermocouple. If the reading is not 1 ohm or
less, replace the thermocouple.

THERMOCOUPLE

VENTURI TUBE

VENTURI TUBE

AIR HOUSING

RETAINING CLIP AND SCREW

LOOSEN THERMOCOUPLE NUT

AUTO RESET
TEMPERATURE
SWITCH

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