High Temperature Monitor System; Location Of Original High Temperature Limit Switch; The Present Configuration Of The High Temperature Limit Switch - Norcold 121X Series Service Manual

Resettable high temperature limit switch
(replacement for non-resettable switches
Figure 8-3. —Location of original high temperature
limit switch (resettable switch shown).

High Temperature Monitor System

The purpose of the high temperature monitor
system is to prevent damage to the cooling
unit due to an overheating condition in the
boiler.
An overheating condition may be cause by one
or a combination of the following:
 Insufficient or obstructed ventilation.
 Inadequate installation in enclosure.
 Heat deflector cap blocked by insulation.
 Heat deflector cap jammed against flue
opening.
 Exceeding off-level limits.
 Operation with two heat sources active.
 Cooling unit blockage.
The high temperature limit switch acts as a
temperature supervising device. This switch is
positioned near the boiler to provide the best
possible monitoring of temperature. Figure 8-3
illustrates the original high temperature limit
64
S 8
ection
Canister
Figure 8-4. —The present configuration of the high
switch configuration with a resettable switch.
Figure 8-4 illustrates the present configuration
of the high temperature limit switch at the time
of this publication.
If the boiler normal operating temperature
begins to rise to an abnormal level, the
electrical contact in the switch opens to
prevent the boiler from overheating.
The controls are programmed to detect when
the switch is open. If the switch is open or not
connected to power board terminals LIMIT IN
and LIMIT OUT, the controls;
 Fault code oP L1 displays
 Stop AC and LP gas operation.
 Record fault in non-volatile memory.
temperature limit switch.