S1 signal can be ignored between the period of the tool ejection command and
the next tool lock command.
S2 is very important in tool change process. It checks whether the tool holder has
ejected, allowing for next step of tool change cycle.
Condition
The tool holder is locked
No tool holder
The tool holder has pop-up (open collet)
THERMAL CONTROL SWITCH
Output S2
0V
0V
十 24V
The electrospindle is protected by two normally closed, bimetallic switches, which protects an
electrospindle motor and cooling fan motor respectively.
The thermal switch must be connected to the numerical control, which in turn must stop the machining
operations as quickly as possible and stop the rotation of the shaft of the electrospindle, if the switch opens.
The switch opens when a temperature that is harmful for the electric coils is reached; the contact closes
automatically when the temperature drops and returns to safe values.
Pin
Power connections (see
section 9.6.4)
Pin
Bimetallic switch
Pin
Electrospindle motor
Pin
Pin
Cooling fan motor
Electrical protection
Pin
Pin
Pin
The thermal control switch of the fan only detects the overheating of the fan motor.
It cannot detect if the fan is working unless the fan is stopped because of
overheating. So, the fan must be checked regularly.
30
