3.7 THERMOSTATS
The user thermostat is a Robertshaw RX model, snap
action electric control with a centre stemadjustment
of temperature up to 190
o
C.
The safety stat is an EGO model with interrupter with
a maximum fixed setting of 230
o
C. This interrupts the
thermocouple signal from pilot and will subsequently
shut down gas supply should user thermostat fail and
cause the oil to overheat.
Note
Manual intervention is required to reset the control in
event of a cut-out.
To Reset
Push button at control base when oil temperature
drops below 215
o
C.
3.7.1 Removal of Operating Thermostat
Isolate main gas supply and drain oil from pan.
Remove control knob from user thermostat and undo
fixing at either end of control panel. Pull panel forward
while easing bottomedge up slightly. Undo fixings
alongside user thermostat spindle and withdraw
thermostat. Follow thermostat phial lead to stuffing
box in pan front wall and undo small compression nut
which seals lead in position. Remove stuffing box nut
and withdraw thermostat phial. Undo thermostat
electrical connections prior to removal of thermostat.
Replace in reverse order.
3.7.2 Recalibration of User Thermostat
Remove knob from thermostat spindle taking care not
to rotate it in either direction. This would change the
setting. Steady spindle and rotate calibration screw
clockwise to decrease and anti-clockwise to increase
temperature. The approximate effect of a quarter turn
is 27
o
C. Replace control knob and allow unit to
operate until temperature has stabilised before
making a final check.
3.7.3 Checking the User Thermostat Calibration
Using a reliable thermometer immersed 25mm below
oil surface at pan centre, measure oil temperature
when a steady condition has been established.
3.7.4 Removal of Safety Thermostat
Isolate gas supply and drain oil frompan.
Undo fixings which secure safety stat to bracket.
Undo fixing which retains thermocouple capillary to
pan base and remove packing. Withdraw phial and
undo wires frominterrupter. Fit replacement stat
bracket and reposition parts in reverse order.
3.8 MULTIFUNCTIONAL GAS CONTROL
Unit is fitted with an SIT 820 Nova control
incorporating cock, governor, valve and flame failure
device.
Removal of the Multifunctional Control
Isolate main gas supply.
Disconnect thermocouple connection on MFC and
pull thermocouple clear. Undo thermopile
connections and withdraw. Undo main gas inlet and
outlet connections to MFC and withdraw control.
Replace in reverse order taking care when
reconnecting thermocouple. DO NOT overtighten as
this may cause damage, hand tight plus a quarter turn
is sufficient.
3.9 GOVERNOR
A governor is built in to multifunctional control. Refer
to Sections 1.9 and 3.8.
