Additional Connections - Danfoss VLT Series Design Manual

®
VLT HVAC Drive Design Guide

5.4. Additional Connections

5.4.1. DC bus connection
The DC bus terminal is used for DC back-up,
with the intermediate circuit being supplied
from an external source.
Terminal numbers: 88, 89
5.4.2. Brake Connection Option
The connection cable to the brake resistor
must be screened/armoured.
1.
2.
5.4.3. Relay Connection
To set relay output, see par. group 5-4* Re-
lays.
NB!
Dynamic brake calls for extra equipment and safety considerations. For further in-
formation, please contact Danfoss.
Use cable clamps to connect the screen to the metal cabinet of the frequency converter
and to the decoupling plate of the brake resistor.
Dimension the cross-section of the brake cable to match the brake current.
NB!
Voltages up to 975 V DC (@ 600 V AC) may occur between the terminals.
NB!
If a short circuit in the brake IGBT occurs, prevent power dissipation in the brake
resistor by using a mains switch or contactor to disconnect the mains for the fre-
quency converter. Only the frequency converter shall control the contactor.
®
MG.11.B2.02 - VLT is a registered Danfoss trademark
Please contact Danfoss if you require further
information.
No 81 82 Brake resistor
.
R- R terminals
+
No 01 - 02 make (normally open)
.
01 - 03 break (normally closed)
04 - 05 make (normally open)
04 - 06 break (normally closed)
5. How to Install
5
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