Danfoss VLT AHF 005 Design Guide

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 Function
81, 82 Brake resistor terminals
Table 10.5 Brake Resistor Terminals
See the VLT
®
Brake Resistor MCE 101 Design Guide for more details.
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 specications.
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%.
Connection Dy11 d0 or Dyn 11d0
Phase shift between secondaries 30°
Voltage dierence between secondaries <0.5%
Short-circuit impedance of secondaries >5%
Short-circuit impedance dierence between secondaries <5% of short-circuit impedance
Other No grounding of the secondaries allowed. Static shield recommended
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
congured 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 Function
100, 101 Auxiliary supply S, T
102, 103 Internal supply S, T
Table 10.6 External Supply
Electrical Installation Con...
VLT
®
HVAC Drive FC 102
170 Danfoss A/S © 11/2017 All rights reserved. MG16C302
1010

Danfoss VLT AHF 005 Specifications

General

Brand	Danfoss
Model	VLT AHF 005
Category	DC Drives
Language	English