Fisher & Paykel Titan Aerotech OD302EU, Руководство по обслуживанию

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Service Manual 546596A: 302 Series Titan Oven June 2005
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5.22 Tracing element faults
(Refer to Technical Overview Section 2.10-2.15 & 2.33)
PROCEDURE:
If the element does not turn off (element run-away)
Note:
In normal operation the element will cycle (turn on & off) when the cavity
temperature has reached the set point. This can be detected by listening for the
switching noise of the element relay switch on the power module or using a current
meter.
1. Check the temperature sensor is reading the correct temperature. (refer to Section
5.23)
2. If the correct temperature is being read, isolate the supply and check that all the
elements are wired correctly and the element relay switches haven’t shortcircuited.
If the element does not heat up
Note:
Before testing refer to Technical Overview Sections 2.10-2.15 & 2.33 to find out
which elements are used for each oven mode.
1. Check for a tripped thermal limiter. (refer to section 5.24)
2. Test the element operation in Technician Mode. (refer to Diagnostics Section 4.3)
3. If the element does not heat up in Technician Mode, test the resistance of the
element. The appropriate range of resistance for each element is given in Table 5.22
below. Replace the element if its resistance is outside the given range.
Element
Min Resistance (
Ω
) Max Resistance (
Ω
)
Upper Inner 19 23
Upper Outer 35 50
Lower 34 47
Fan 21 26
Throat 77 218
Catalytic Converter 300 600
Table 5.22
4. Check the continuity of the element wiring back to the power module, including the
thermal limiters and the isolating relay.
Note: The isolating relay is only energised when an oven mode is selected.
5. If the wiring continuity is good, it is likely that the element is not faulty. (refer to
Symptom Procedure Checklist for further component tests)