L.B. White Premier TS350DF 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 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.
2. Holding a switch by one of its mounting legs,
on the back of the switch.See Fig. 28. Be careful
not to melt the plastic housing of the switch
when conducting this test.
FIG. 28
Reset Button
Terminal
Mounting Legs
3. Within a minute, you should hear the contacts of
the switch have opening.
4. Allow the switch to cool for about a minute
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
Fan Wheel, Bearings
and Shaft
1. Remove the following:
a. Belt guard and belt.
b. Bolts and washers securing the bearing platform at
the heater's base.
c. Screws securing the fan panel to the fan housing.
2. Slide the complete assembly from the heater.
3. Replace the components as needed
and fan pulley. See Fig. 29.
FIG. 29
Pulley hub
with pulley hub
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 discon-
nect control valve's electrical wiring. See Fig. 30.
Fan wheel
shaft end
Main support