
B-65332EN/01 HANDLING, DESIGN, AND ASSEMBLY 2.MECHANICAL DESIGN
2.2 THERMOSTAT CONNECTION
A stator has a built-in thermostat used to prevent the motor from
overheating. The specification of the thermostat is as follows:
- Actuation temperature: 90°C±5°C (temperature inside the motor)
- Normal close (Usually, the contact is closed. The contact is
opened at 90°C±5°C.)
- Use 24 VDC (1A or less).
From the stator, two leads are extended. These leads are to be
connected to the I/O (PMC) of the CNC. The leads have no polarity.
Configure a system (such as a PMC ladder) so that when the
thermostat is actuated (the contact is opened), alarm information is
passed from the PMC to the CNC and the machine stops safely for an
mergency stop. The normal method of connection is shown below. e
In normal operation (when the motor is not overheated)
PMC
CNC
Drives the
system.
TH1
TH2
Stator
Contact closed
When the motor is overheated
PMC
CNC
Emergency
stop
TH1
TH2
Stator
Contact opened
larm information
CAUTION
1 Without connecting a thermostat, the motor can be
driven. In such a case, however, the motor cannot
be protected from overheating. So, be sure to
connect a thermostat according to the method
described above before driving the motor.
2 If an emergency stop is performed immediately
after an overheat is detected, the motor can coast,
for example, during acceleration, or an axis drop
can occur. It is recommended that when an
overheat is detected, the machine be stopped
safely and quickly by using a brake as required
before performing an emergency stop.
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