Danfoss VLT HVAC Series

3.23.2 25-0* System Settings
Parameters related to control principles and configuration of the system.
25-00 Cascade Controller
Option: Function:
For operation of multiple devices (pump/fan) systems where capacity is adapted to actual load by
means of speed control combined with on/off control of the devices. For simplicity, only pump sys-
tems are described.
[0] * Disabled The cascade controller is not active. All built-in relays assigned to pump motors in the cascade
function will be de-energized. If a variable speed pump is connected to the adjustable frequency
drive directly (not controlled by a built-in relay); this pump/fan will be controlled as a single pump
system.
[1] Enabled
25-02 Motor Start
Option: Function:
Motors are directly connected to the line power with a contactor or a soft starter. When the value
of par.25-02
Motor Start is set to an option other than Direct on Line [0], then par.25-50 Lead Pump
Alternation
is automatically set to the default of Direct on Line [0].
[0] * Direct on Line Each fixed speed pump is directly connected to line via a contactor.
[1] Soft Starter Each fixed speed pump is connected to line via a soft starter.
[2] Star-Delta
3 Parameter Description VLT
®
HVAC Drive Programming Guide
3-236 MG.11.C6.22 - VLT
®
is a registered Danfoss trademark
3