PAGE 5 of 61 HO-7-1237 & HO-4-1234 OIL-FIRED HEATERS
© SAMUEL JACKSON, INCORPORATED 2003 ALL RIGHTS RESERVED
WHERE DO I INSTALL THE THERMOCOUPLES?
The thermocouples are color-coded to assist the user in the installation of the correct
thermocouple in the before and after-mix locations. A thermocouple with red on the mounting
threads is for installation before the mix-point. This is the high limit thermocouple. The stainless
protection sheath is trimmed back exposing the sensing tip for fast response. This exposed
thermocouple should not be used in pipes with cotton flow.
A thermocouple with blue paint on the pipe threads is for installation after the mix-point. This is
the primary temperature sensor. The stainless sheath is left intact over the sensor bulb to protect it
from abrasion.
Referring to Figure 2, placement of the primary thermocouple on the inner radius side after an
elbow will protect it from abrasion. Angling the thermocouple 45 degrees in the direction of
cotton flow will prevent cotton and trash from tagging on the thermocouple.
In Samuel Jackson drying systems, the blue primary thermocouple is placed after the dryer’s
skimmer in the skimmed air. For tower drying systems, this thermocouple should be placed in the
top of the tower or in the transition immediately before the tower. Due to the responsiveness of
the temperature controls, placing this thermocouple farther down in the tower will cause control
instability.
For heaters operating with Hot Boxes and module feeders, with the cotton going to an unloading
separator, place the primary thermocouple in the seed cotton pipe before the unloading separator.
Call the factory for information on feed control operation when used in conjunction with a
module feeder and heater.
Figure 2 –
Basic Temperature Control
14-3567.3
