Castle TSM-21 Serial 61076 to 64233 (Parker) Operator Manual - Manual (Page 30)

Safety Switch
The Safety Switch on the TSM-21 consists of a magnet (no wires) mounted near a magnetic reed
switch (with wires). (Figure 24) When the Safety Buttons are pushed by the work piece, they
raise an L-shaped metal blade that rests between the reed switch and the magnet inside the
machine. The assembly is wired in such a way that when the blade is raised the switch closes
allowing electricity to flow to the Foot Pedal.
Figure 24
ƒ Turn the power to the machine off.
ƒ First make sure that the side of the magnet housing with the notch in it is facing the
Safety Blade. This ensures that the magnet is as close to the reed switch as possible.
ƒ If there is no notch in the housing, then detach it from the machine and visually inspect it.
Make sure that the magnet is turned so that it is closest to the Safety Blade.
ƒ If the above steps don't work then test for proper function at the switch by connecting
ohmmeter leads to the screw terminals on the reed switch.
ƒ When the blade is resting between the reed switch and magnet, an open circuit should be
registered (a few kilo ohms of resistance is acceptable).
ƒ When the blade is raised a closed circuit should be registered (approximately 0 ohms). If
an open circuit is still registered, then the distance between the mounted assembly may
need to be reduced by
1
/
16
” on each side. Loosen the nuts holding the switch and magnet
to the case top, then pinch them slightly closer and retighten the nuts.
ƒ If this still doesn't fix the problem then a new switch assembly (magnet and reed switch)
should be installed.
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