Repair Primary Heater
Replace Heater Element
1. Follow
Before Beginning Repair, page 52
.
2. Wait for heaters to cool.
3. Remove heater cover.
4. Disconnect heater element wires from heater
wire connector inside the electrical enclosure.
See
Electrical Schematics, page 94
. Test with
an ohmmeter.
System
Total
Heater
Wattage
Element
Ohms per
element
H-30
10 kW
2,550
18–21
H-30,
H-40,
H-XP2
15 kW
2,550
18–21
H-40,
H-50,
H-XP3
20 kW
2,550
18–21
5. If the RTD is on the heater element, remove
the RTD (512) to avoid damage. See
.
6. Use a wrench to remove the heater element
(508). Inspect element. It should be relatively
smooth and shiny. Replace element if there is a
crusted, burnt ash-like material adhered to the
element, or if the sheath shows pitting marks.
7. Install the new heater element (508), holding the
mixer (510) so it does not block the RTD port.
Torque to 120 ft-lbs (163 N•m).
8. Install the RTD (512), if removed earlier. See
.
9. Reconnect the wires inside the electrical
enclosure.
Line Voltage
The heater outputs its rated wattage at 230 VAC.
Low line voltage will reduce power available and the
heater will not perform at full capacity.
Repair Heater Overtemperature
Switch
1. Perform
.
2. Wait for heaters to cool.
3. Disconnect overtemperature switches (509) from
cable (88). Test across spade terminals with
ohmmeter.
a. If the resistance is not approximately 0 ohms,
the overtemperature switch (509) needs to
be replaced. Go to step 5.
b. If the resistance is approximately 0 ohms,
inspect cable (88) to ensure it is not cut or
open. Reconnect the overtemperature switch
(509) and cable (88). Disconnect cable from
the TCM. Test from pin 1 to 3 and 1 to 4. If
the resistance is not approximately 0, and
switches are 0, replace cable in place or
original cable.
4. If the switch fails the test, remove the screws.
Discard the failed switch. Apply a thin layer of
thermal compound 110009, install a new switch
(509) in the same location on housing (501).
Secure with screws (513) and reconnect cables
(88).
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