Moffat turbofan E32SUBC, Руководство по обслуживанию

Страница: 33 / 68

29
5
Trouble-shooting
Revision 3
© Moffat Ltd, September 2009
E32SUBC OVEN and PROOFER
5.4.5 Auto-fill not filling or
overflowing
Water solenoid faulty
Empty water tank so float switch is in lowest
position. With power ON check voltage across
water solenoid coil terminals. If voltage is correct
(refer electrical rating plate) but solenoid is not
operating, disconnect electrical supply and
remove wire connections from solenoid. Check
solenoid coil windings resistance.
Correct coil resistance:
208 - 240 volt models 3650 Ω
NOTE: If open circuit/high resistance, then the
coil is faulty– replace.
If coil is correct, rewire and listen for audible
solenoid click when power is supplied. If solenoid
can be heard functioning and water supply is
turned on but no water is entering tank, remove
water solenoid and fittings and check for
blockages.
SOLENOID RELAY - TANK FILLING
Figure 5.4.5a
When the water level reaches the full position the
float switch supply’s power to the relay coil,
which in turn cuts power to the water solenoid
and supply’s power to the humidity tank element
relay through terminals 5 and 3. Terminals 2 and
6 supply a signal to the controller to show the
water tank is full. If the tank does not fill within
30 seconds a low water alarm will sound.
Figure 5.4.5b
SOLENOID RELAY - TANK FULL
5.4.4 No humidity control
Humidity probe faulty
To verify reading refer to 3.4.6
Switch the proofer on. Check that the humidity
control cycles on / off, and using a suitable probe
measure the temperature of the water in the
trough. The water temperature should be 50°
C/120°F ± 10%. If the temperature continues to
rise above this then the humidity temperature
probe is faulty - replace.
Water level float switch faulty
To verify reading refer to 3.4.6
To check correct operation of float switch
remove the float switch wire connections from
terminal 8 and terminal 5 on relay. With full
water tank (float switch in raised position) float
switch should be closed circuit. With empty
water tank (float switch in lower position) float
switch should be open circuit. If not, float switch
is faulty—replace.
Solenoid relay faulty
E32SUBC auto-fill models are fitted with a 2 pole
change over relay, with its coil controlled by the
float switch located in the water trough / tank.
When the water level is below the full position
the coil is not energised, allowing the relay to
supply power to the water solenoid through ter-
minals 5 and 1
Element blown
With controller on and heating check voltage
across wet element terminals. If there is no volt-
age check wiring. If voltage is correct,
element is faulty - replace.
To test element, disconnect terminals and check
resistance across element.
Resistances;
Proofer wet element:
72 Ω ± 5%
8
7
4 2 3 1
6 5
8
7
4 2 3 1
6 5