Rockwell Automation LC-Series Linear Motor - Manual (Page 29)

Item Number 814036 - Rev C
Installation 2-23
Motor (Coil) Thermal
Protection
1. Typical digital drives have “RMS” current protection and I
2
T or
estimated temperature vs. time software protection schemes. These
available features should be activated and set according to the motor
model ratings for this application.
2. The selected drive should have
±
peak current magnitude limits that
should be set according to the motor’s peak current rating, as a
maximum.
3. For drives without adjustable/available motor protection features,
motor fuses (current rating not to exceed motor continuous RMS)
should be installed per the Local/National Electrical Code. Fuses
should be time-delay type and rated for the drive PWM output voltage.
ATTENTION
!
LC motors with the thermal protection option will supply a
signal that indicates the motor temperature limit condition.
This signal should be used by the motor control/drive
system to immediately shut down the motor power on an
open condition. Since linear motors are generally not
repairable, and typically highly integrated into the
mechanical structure, redundant motor thermal protection
is strongly recommended.
Table 2.R Thermistor and Thermal Switch Resistance vs. Temperature
Temperature (°C) Resistance in Ohms
Thermistor
-20 to 110
≤ 300
125
≤ 1650
135
≥ 4000
Thermal Switch
20 to 130
≤ 1
>130 Open