L.B. White Premier Owner's Manual And Instructions page 22

22
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
disconnect power to the gas control valve if either
senses an overheat condition.
Both high limit switches should be tested a
minimum 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.
A
2. Holding a switch by one of its mounting legs,
apply a small flame only to the sensing portion
on the back of the switch.See Fig. 30. Be careful
not to melt the plastic housing of the switch
when conducting this test.
FIG. 30
Reset Button
Terminal
Mounting Legs
A
3. Within a minute, you should hear a "click"
indicating the contact of the switch opened.
4. Allow the switch to cool for about a minute
before firmly pressing its reset button. Put the
red cap back on the switch.
5. Check for electrical continuity across the switch
terminals to make sure the contacts have
closed.
Owner's Manual • Premier 350 2.0
Fan Wheel, Bearings
and Shaft
1. Remove the following:
a. Belt guard and belt.
b. Bolts and washers securing the bearing platform at
c. Screws securing the fan panel to the fan housing.
2. Slide the complete assembly from the heater.
3. Replace the components as needed
4. When reinstalling, ensure fan shaft is flush with fan hub
and fan pulley. See Fig. 31
FIG. 31
Pulley hub
Shaft flush
with pulley hub
Shaft flat
Sensing Surface
Flame
Burner Orifice and Gas
Control Valve
1. Remove hose and pipe nipple from control valve inlet.
2. Open burner end door.
3. Remove the screws from gas control bracket and
disconnect control valve's electrical wiring. See Fig. 32.
the heater's base.
Bearing race flush with front edge of shaft flat.
Set screws tightened to flats.
Fan wheel
Fan hub flush with
shaft end
Main support
A-A
SECTION