602
Thermo 230 / 231 / 300 / 301 / 350
6 Functional Checkouts
6.3
Components Testing
6.3.1 Temperature Sensor Resistance Check
When checking the temperature sensor with a digital
multimeter the values of the following diagram must be
obtained. Resistance checking is preferably performed at
ambient temperatures between 20 °C and approximately
100 °C (immerse sensor in water).
6.3.2 Flame Sensor Resistance Check
NOTE:
The glass bulb of the flame sensor and the viewing glass
of the window (refer to Fig.) are to be cleaned if
contaminated. In case of damage or not obtaining the
rated values replace flame sensor.
Check
–
cover flame sensor glass bulb
–
check resistance (rated value: < 20 kOhm)
–
uncover flame sensor glass bulb and expose to light
of strong lamp.
–
check resistance (rated value: < 400 Ohm)
6.3.3 Igniter Electrodes Check
NOTE:
The insulator of the igniter electrodes must show no
damage. Igniter electrodes with a gap out of tolerance or
not working properly must be replaced.
Check
–
inspect insulators of igniter electrodes for damage
6.3.4 Igniter Box Check
NOTE:
The igniter box may also be tested using the PC heater
diagnosis (component test).
High voltage; 13,000 volts arcing across the igniter
electrodes.
ATTENTION:
Do not apply voltage to igniter box without electro-
des.
Check
–
apply 24V as shown on figure
–
normal condition: spark between electrodes.
Water temperature °C
Resist
ance (O
hm)
100
50
10
1000
5000
10000
R/y
T/°C
20 °C
≅
4419 ..... 4892
W
100 °C
≅
319 ..... 348
W
Viewing glass
Glass bulb
High voltage!
Danger to life!
Warning!
Igniter electrodes 13,000 Volt
10kOhm
Summary of Contents for spheros thermo 230
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