Vacon OPTAF, User Manual

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vacon • 40 THERMISTOR FUNCTION (ATEX)
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4.1 Technical data
Figure 17. The layout of the OPTAF board
4.1.1 Functional description
The thermistor supervision circuit of the OPTAF board is designed to provide a reliable way of dis-
abling the drive modulation in case there is an overtemperature at the motor thermistor(s).
By disabling the drive modulation the feeding of the energy to the motor is prevented and a further
heating up of the motor due to this is avoided.
The thermistor supervision circuit meets the requirements in the ATEX directive by acting directly
on the "STO" safety function of the VACON
®
NXP (See Figure 16) and is thus providing a reliable,
software and parameter independent way of preventing the energy supply to the motor.
11052.emf
+24V+
+24V-
+24V+
+24V-
SD1
SD2
Jumper wire X12
See Chapter 4.2.4.
Jumper X10 for selecting
thermistor short
circuit supervision
Thermistor input
Thermistor Input: Thermistor
active > 4000 ohm. After being
active, the fault can be reset if
resistance is < 2000 ohm.
STO inputs two
independent channels
Programmable
Relay
"NO/NC"
Programmable
Relay
"NO"