Motor Thermal Protection - Danfoss VLT AutomationDrive FC 300 Design Manual

6. How to Install

6.5.8. Motor Thermal Protection

The electronic thermal relay in the frequency converter has received the UL-approval for single
motor protection, when par. 1-90
current, I
For thermal motor protection it is also possible to use the MCB 112 PTC Thermistor Card option.
This card provides ATEX certificate to protect motors in explosion hazardous areas, Zone 1/21 and
Zone 2/22. Please refer to the
6.5.9. Motor Thermal Protection
The electronic thermal relay in the frequency converter has received the UL-approval for single
motor protection, when par. 1-90
current, I
For thermal motor protection it is also possible to use the MCB 112 PTC Thermistor Card option.
This card provides ATEX certificate to protect motors in explosion hazardous areas, Zone 1/21 and
6
Zone 2/22. Please refer to the
6.6.1. Installation of Brake Cable
(Only for frequency converters ordered with brake chopper option).
The connection cable to the brake resistor must be screened.
1.
2.
See Brake instructions, MI.90.FX.YY and MI.50.SX.YY for more information about safe installation.
6.6.2. RS 485 Bus Connection
One or more frequency converters can be con-
nected to a control (or master) using the
RS485 standardized interface. Terminal 68 is
connected to the P signal (TX+, RX+), while
terminal 69 is connected to the N signal
(TX-,RX-).
If more than one frequency converter is con-
nected to a master, use parallel connections.
In order to avoid potential equalizing currents in the screen, earth the cable screen via terminal
61, which is connected to the frame via an RC-link.
120
Motor Thermal Protection
is set to the rated motor current (see motor name plate).
M,N
Design Guide
Motor Thermal Protection
is set to the rated motor current (see motor name plate).
M,N
Design Guide
Connect the screen by means of ca-
ble clamps to the conductive back
plate on the frequency converter and
to the metal cabinet of the brake re-
sistor.
Size the brake cable cross-section to
match the brake torque.
NB!
Voltages up to 960 V DC, depending on the supply voltage, may occur on the ter-
minals.
MG.33.B9.02 - VLT
is set for ETR Trip
for further information.
is set for ETR Trip
for further information.
No. Function
81, 82 Brake resistor terminals
® is a registered Danfoss trademark
FC 300 Design Guide
and par. 1-24 Motor
and par. 1-24 Motor