Vacon OPTAF, User Manual

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THERMISTOR FUNCTION (ATEX) vacon • 43
Local contacts: https://www.danfoss.com/en/contact-us/contacts-list/
4.2 Commissioning
NOTE! Installation, testing and service work on the OPTAF board can be performed only by profes-
sional persons.
NOTE! It is not allowed to perform any repair work on the OPTAF board.
The OPTAF option board has an overvoltage protection that can activate due to fast transients when
connecting the +24 V. The activation causes the +24 V input to be short-circuited. It is essential to
protect the drive and the supply with a fuse placed on the supply line according to the instructions
in the drive operating guide. See, for example, VACON
®
NXS/NXP Air-cooled Wall-mounted and
Standalone Operating Guide. Do not use fuses with higher current rating. If the behavior reoccurs
after replacing the fuse, contact Danfoss for technical support.
4.2.1 General wiring instructions
The thermistor connection must be done using a separate control cable. It is not allowed to use
wires belonging the motor supply cables or any other main circuit cables. It is recommended to use
a shielded control cable.
NOTE! It is recommended to test the ATEX functionality using thermistor input on OPTAF board pe-
riodically (typically once a year). For testing, the thermistor connection to the OPTAF board is dis-
connected. The drive ready signal goes low (green LED on the keypad goes OFF). Check for the
corresponding warning or fault indication in the drive according to the parameter setting explained
in Chapter 4.2.2.
4.2.2 Parameter setting for ATEX function
In case of overtemperature, the drive modulation is disabled. The drive will not anymore feed ener-
gy to the motor thus preventing further overheating of the motor. See Figure 16.
When drive is connected to the main power and if the motor temperature is below overtemperature
limits (see Figure 18), the drive goes to ready state. The motor may start in presence of start com-
mand from a selected control place.
If the motor temperature is above the overtemperature limits (see Figure 18), fault /warning (F29)
thermistor is activated depending on the programming in the application.
The application programming for the thermistor fault is as follows e.g. in factory applications.
* With OPTAF board according to ATEX directive 94/9/EC (i.e jumper wire X12 not cut) , response
to thermistor fault = 2 is always same as response to thermistor fault =3, i.e. stop by coasting.
When the resistance of the thermistor(s) mounted in the motor goes above 4 k
Ω
due to motor over-
heating, the drive modulation is disabled within 20 ms. Fault F29 or warning A29 is generated in the
drive according to the above-mentioned programming.
Maximum cable length without
short circuit monitoring
X10: OFF Maximum cable length with
short circuit monitoring
X10: ON
>= 1.5 sq mm 1500 meters 250 meters
Code Parameter Default ID Note
P2.7.21 Response to
Thermistor Fault 2 732 0= No Response
1= Warning
2= Fault according to Stop Mode. *
3= Fault, stop by coasting.