20-Ampere Fuse, Fuse Failure - Thermador CM301B Service Manual

Lit. No. 94-30-006B
The Microwave Oven is protected from interlock switch failure by a 20 ampere Fuse. A
defective switch or any other factor causing an overload on the microwave circuit will
blow the fuse and stop the operation of the microwave section of the oven. The fuse is
located in a fuse holder in the upper plenum.
Microwave Fuse Failure:
The purpose of the fuse system is to prevent operation of the unit in the event of a safety
switch failure. The safety switches prevent the unit from emitting microwave energy if
the door is not completely closed. The following is an explanation of the safety switches
and an explanation of the fuse protection system. The safety switches are the monitor
switch and the latch interlock switch (primary switch), and the right side door interlock
switch (secondary switch).
The latch interlock switch (primary switch) is mounted on the latch assembly. The latch
interlock switch is closed by the latching of the motorized oven door latch.
The monitor switch and the right side door interlock switch (secondary switch) are
activated by the door strike movement.
Fuse Failure Modes:
The fuse can open due to any of the following failure modes:
1) A short in the microwave circuit or a component failure that causes the microwave
circuit to draw more than 20 amps.
2) The monitor switch is closed when the latch's interlock switch is also closed.
DO NOT ATTEMPT TO REPAIR A SAFETY SWITCH.
REPLACE A FAILED SAFETY SWITCH.
20 AMPERE FUSE
Page 65
CM Oven Service Manual