1.5.1.1 Markings of the Frequency
Converter
A sticker is delivered with the option as spare part or with
the frequency converter to signify ATEX certification. Apply
this sticker to the front of the frequency converter in
which the ATEX module is integrated. The sticker indicates
that the ATEX module is installed in the frequency
converter.
MS 220 DA / MCB112
Code no.: 130B1137
Motor protection inside
See manual
for additional instruction
PTB 14 ATEX 3012U
CAUTION:
II (2) D [Ex tb][Ex tc]
II (2) G [Ex e] [Ex d] [Ex n]
ε
130BE103.10
Illustration 1.1 Label to Apply to Frequency Converter
1.5.2 Foreseeable Misuse
Any use not expressly approved by Danfoss constitutes
misuse. This also applies to failure to comply with the
specified operating conditions and applications.
Danfoss assumes no liability of any sort for damage attrib-
utable to improper use.
Only operate with explosion-protected 3-phase motors
which are built, tested and labelled separately for
frequency converter use.
WARNING
EXPLOSION DANGER
Zone 0 and Zone 20 are not applicable to electric
motors.
To avoid explosion, only use motors in:
•
Zone 1/21.
•
Zone 2/22.
1.5.3 Thermal Motor Protection
According to ATEX Directive 94/9/EC and Standard EN
60079-14, motor overload protection is a requirement.
The MCB 112 monitors the temperature in the motor
windings with an ATEX-approved motor overload
protection device. If there is a critical temperature level or
a malfunction, switch off the motor. If the frequency
converter is equipped with 3–6 PTC thermistors in series
according to DIN 44081 or 44082, the MCB 112 offers
ATEX-approved monitoring of the motor temperature.
Alternatively, an external ATEX-approved PTC protection
device can be used.
1.5.4 ATEX ETR Thermal Monitoring
NOTICE
The ATEX ETR thermal monitoring function only applies
to Ex-e and Ex-n motors and is only available for VLT
®
AutomationDrive FC 302 frequency converters.
The FC 302 with firmware version V6.3x or higher is
equipped with an ATEX ETR thermal monitoring function
for operation of Ex-e motors according to EN 60079-7 and
Ex-n motors according to EN 60079-15. Combined with an
ATEX-approved PTC monitoring device like MCB 112, the
installation does not need an individual approval from an
approbated organisation, that there is no need for
matched pairs.
The feature makes it easier to apply Ex-e and Ex-n motors
instead of the more expensive, larger, and heavier Ex-d
motors. The use of Ex-e and Ex-n motors is possible by
ensuring that the frequency converter limits the motor
current to prevent the motor from heating up.
1.5.5 Tripping Function
The MCB 112 includes a tripping stage for PTC thermistor
sensors with safe potential separation of supply voltage
from ground. The tripping function switches off the +24 V
DC directly at terminal 37 on the frequency converter.
The PNP logic output terminal X44/10 signals the status in
case of failure. The MCB 112 works according to the
closed-circuit principle. The device trips in case of short
circuit or line interruption.
1.5.6 Safe Separation
The PTC thermistor circuit (T1, T2) has a safe separation of
low-voltage electric circuits PELV, see
chapter 3.2 Instal-
lation of Sensor Circuit Wires
.
1.5.7 Safe Disconnection Principle
The Safe Torque Off function disables the control voltage
of the power semiconductors or the frequency converter
output stage. Disabling the control voltage prevents the
inverter from generating the voltage required to rotate the
motor.
Introduction
VLT
®
PTC Thermistor Card MCB 112
4
Danfoss A/S © 01/2015 All rights reserved.
MG33V302
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