Manual Reset High Limit Switches - L.B.White TS350 Manual Del Usuario E Instrucciones

Manual Reset High Limit
Switches
WARNING
Burn Hazard
■ Do not operate the heater with the high limit
switch bypassed.
■ Operating the heater bypassed high limit switch
may lead to overheating, possibly resulting in a
fi re, with subsequent damage to the heater or
property damage.
This heater has two high limit switches. One is located at
the burner end of the heater on the heat chamber. See
Fig. 28. The other is located on the fan housing behind
the fan motor. See Fig. 29.
FIG. 28
Burner End Limit
FIG. 29
Their purpose is to safely shut the heater down if the
heater should overheat.
Burner end limit: Protects the burner and associ-
ated wiring from overheating caused by excessive gas
pressure.
Premier Ductable Heaters
Motor end limit: Protects from overheating if
the duct is kinked or restricted, or if the air inlet is
blocked.
The switches are wired in series and will discon-
nect power to the gas control valve if either senses
an overheat condition.
Both high limit switches should be tested a mini-
mum of once per year when the heater is given a
thorough cleaning.
1. Remove the high limit switches from the heater.
Also remove the red cap from both switches.
The burner end limit switch has a washer located
between each leg of the limit switch and the
heat chamber. The washers act as spacers and
prevent the switch from tripping prematurely.
Both must be reinstalled after conducting this
test. See Fig. 30.
FIG. 30
2. Holding a switch by one of its mounting legs,
apply a small fl ame only to the sensing portion
on the back of the switch.See Fig. 31. Be careful
not to melt the plastic housing of the switch
when conducting this test.
FIG. 31
RESET BUTTON
MOUNTING
LEG
3. Within a minute, you should hear the contacts of
the switch have opening.
Owner's Manual • Premier 350
(#8 - 3/16 ID x
7/16 OD x .041
TERMINAL
27
Washers
Thickness)
SENSING
SURFACE
FLAME