TWL: Exhaust overheat alarm sensor location on Lehman 120s
Subject: TWL: Exhaust overheat alarm sensor location on Lehman 120s
From: Martin G. White MD (mgwhite@XXX.XXX)
Date: Thu May 02 2002 - 08:55:33 EDT
While, I have no experience with Lehman engines, I have recently had the
following experience with overheat alarms with my single Isuzu 6RBIT. I have
both a pyrometer which is located in the engine exhaust gas stream just
before the mixing elbow, and heat sensors located above the engine, on the
engine overhead. The latter could be called "fire alarms" and are designed
to close the circuit at about 160 F. First the temperature measured by the
pyrometer when idling is about 240 F, when underway with moderate load, 440
F, and when WOT, black smoke, 880 F. Therefore, any of these temps would
have triggered an overheat alarm set for 160 F. Further, I had to move the
"fire alarm" from a position directly above the engine to the side, to
prevent it from going off inappropriately.
Hope these observations help.
Marty White
Skipper, INSPIRATION, Kristen 46
Van Isle Marina, Sidney, B.C.
