Manual Reset High Limit Switches - L.B. White Premier TS080 Manuel Du Propriétaire

Manual Reset High Limit
Switches
WARNING
Fire 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 limit switches: one inside the solid
door end on the heat chamber, the other inside the
louvered door end mounted on the fan housing side
panel. Both are easily identifi ed by a red reset button in
the center of the switch. See Figs. 27 and 28, Premier
170 shown.
FIG. 27
Burner end high limit
FIG. 28
Fan end
high limit
Premier Ductable Heaters
Function
If the heater overheats, one or both of the limit switches
can trip, opening the electrcial circuit to the gas control
valve. Overheating is generally caused by duct restric-
tions, low voltage, blocking the heater's air inlet, or exces-
sive gas pressure.
Resetting
If either trips, remove the red cap and fi rmly press the
reset button in the middle of the switch. Then, shut the
heater off and turn it back on. Determine the cause of the
limit tripping.
Testing
To ensure proper function of these critcal safety compo-
nents, both switches should be tested annually, typically
when the heater is given a thorough cleaning.
1. Remove either high limit switch.
2. Holding the switch by one of its mounting legs, apply
a small, soft fl ame only to the sensing portion on the
back of the switch. See Fig. 29. Be careful not to melt
the plastic housing of the switch when conducting this
test.
3. Within a minute, you should hear a click coming from
the switch, indicating the contacts of the switch have
opened.
4. Allow the switch cool down for about a minute. Remove
the red cap and fi rmly press the reset button on the
switch.
5. Check for electrical continuity across the switch ter-
minals to make sure the contacts have closed. Install
the red cap.
FIG. 29
RESET BUTTON
MOUNTING
LEG
Owner's Manual • Premier 80-170
TERMINAL
27
SENSING
SURFACE
FLAME