Danfoss VLT HVAC Drive FC 102 Design Manual page 172

Electrical Installation Con...
10.3.4 Brake Cable Connection
The connection cable to the brake resistor must be shielded and the maximum length from the drive to the DC bar is
limited to 25 m (82 ft).
•
Use cable clamps to connect the shield to the conductive backplate on the drive and to the metal cabinet of the
brake resistor.
•
Size the brake cable cross-section to match the brake torque.
Terminal
81, 82
Table 10.5 Brake Resistor Terminals
®
See the VLT
NOTICE
If a short circuit in the brake module occurs, prevent excessive power dissipation in the brake resistor by using a mains
switch or contactor to disconnect the mains from the drive.
10.3.5 Transformer Connection
Transformers used along with 12-pulse drives (F8–F13) must conform to the following specifications.
Loading is based on 12-pulse K-4 rated transformer with 0.5% voltage and impedance balance between secondary windings.
Leads from the transformer to the input terminals on the drive are required to be equal length within 10%.
10 10
Connection
Phase shift between secondaries
Voltage difference between secondaries
Short-circuit impedance of secondaries
Short-circuit impedance difference between secondaries
Other
10.3.6 External Fan Supply Connection
In case the drive is supplied by DC or the fan must run independently of the mains supply, an external supply can be
connected via the power card.
The connector, which is on the power card, connects the mains voltage to the cooling fans. The fans are configured at the
factory to connect to a common AC line. Use jumpers between terminals 100–102 and 101–103. If external supply is
needed, the jumpers are removed and the supply is connected to terminals 100 and 101. Use a 5 A fuse for protection. In
UL applications, use a Littelfuse KLK-5 or equivalent.
Terminal
100, 101
102, 103
Table 10.6 External Supply
170
Function
Brake resistor terminals
Brake Resistor MCE 101 Design Guide for more details.
Function
Auxiliary supply S, T
Internal supply S, T
Danfoss A/S © 11/2017 All rights reserved.
®
VLT HVAC Drive FC 102
No grounding of the secondaries allowed. Static shield recommended
Dy11 d0 or Dyn 11d0
30°
<0.5%
>5%
<5% of short-circuit impedance
MG16C302