Onan DJA Series User Manual

VERNATHERM BRACKET
ADJUSTING AND MOUNTING
SCREWS IN SLOTTED HOLES
EARLY MODELS
ADJUST THE VERNATHERM
POWER ELEMENT TO REST
ON THE ROLL PIN WITH
SHUTTER CLOSED AT AMBIENT
TEMPERATURE
LATE MODELS
UPPER SHUTTER
ACTUATING ROD
SHUTTERS
VERNATHERM
POWER ELEMENT
LOWER SHUTTER
ACTUATING ROD
ADJUST THE VERNATHERM
POWER ELEMENT TO REST
ON THE ROLL PIN WITH
SHUTTER CLOSED AT AMBIENT
TEMPERATURE
FIG. 5-3
loosen the power element mounting screws and slide the
assembly until it touches the roll pin with the shutter closed.
Repair: If the shutter will not open, check the power element
for defects or binding of the plunger. Be sure the shutter
does not bind against the housing in any position.
To test the power element, remove it from the assembly and
heat it. When the unit reaches about 120
o
F, the plunger
should start to move out. Total movement should be at
least 1/5". Do not overheat.
If the unit will not close, check for a weak return spring,
binding in the nylon bearings or dirt in tiu- power element
plunger. If the nylon bearings are wom or bind, replace
them. Remove the shutters and pull out the stub shaft.
Push out the old and push in new bearings from the inside
of the shutter housing. The large bearing surface serves as
a spacer bushing so must be on the inside of the housing.
The shutters should be adjusted to obtain an end thrust
clearance of not more than 1/32".
HIGH TEMPERATURE CUT-OFF
When optional automatic air discharge shutter is used,
shutter includes a high temperature cut-off switch. This
switch protects the plant if shutter fails to open. The
switch is in series with the governor solenoid. Switch is
normally closed and opens at about 240
o
F. When it opens,
the solenoid is de-energized, stopping the unit. The switch
closes again at about 195°.
11

Onan DJA Series Specifications

General

Brand	Onan
Model	DJA Series
Category	Engine
Language	English