General Description - Danfoss VLT AQUA Drive FC 202 Design Manual

Selection
Illustration 3.12 Cascade Control of Multiple Pumps
The cascade controllers are optional hardware and
software components that can be added to the VLT
AQUA Drive FC 202. It consists of an option board
containing three relays that is installed in the B option
location on the drive. Once options are installed, the
parameters to support the cascade controller functions are
available through the control panel in parameter group 27-
** Extended Cascade Control. The extended cascade
controller offers more functionality than the basic cascade
controller. It can be used to extend the basic cascade with
three relays and even to eight relays with the advanced
cascade control card installed.
While the cascade controller is designed for pumping
applications and this document describes the cascade
controller for this application, it is also possible to use the
cascade controllers for any application requiring multiple
motors configured in parallel.
Master/follower operation
The cascade controller software runs from a single VLT
AQUA Drive with the cascade controller option card
installed. This frequency converter is referred to as the
master drive. It controls a set of pumps each controlled by
a frequency converter or connected directly to mains
through a contactor or through a soft starter.
Each additional frequency converter in the system is
referred to as a follower drive. These frequency converters
do not need the cascade controller option card installed.
They are operated in open loop mode and receive their
speed reference from the master drive. The pumps
connected to these frequency converters are referred to as
variable speed pumps.
Each additional pump connected to mains through a
contactor or through a soft starter is referred to as a fixed
speed pump.
Each pump, variable speed or fixed speed, responds to a
relay in the master drive. The frequency converter with the
cascade controller option card installed has five relays
available for controlling pumps. Two relays are standard in
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VLT AQUA Drive FC 202 Design Guide
the frequency converter and an additional 3 relays are
found on the option card MCO 101 or 8 relays and 7
digital inputs on option card MCO 102.
The difference between MCO 101 and MCO 102 is mainly
the number of optional relays being made available for the
frequency converter. When MCO 102 is installed, the relays
option card MCB 105 can be mounted in the B-slot.
The cascade controller can control a mix of variable speed
and fixed speed pumps. Possible configurations are
described in more detail in 3.6.9 General Description. For
simplicity of description within this manual, pressure and
flow are used to describe the variable output of the set of
®
pumps controlled by the cascade controller.

3.6.9 General Description

The cascade controller software runs from a single VLT
AQUA Drive FC 202 with the cascade controller option
card installed. This frequency converter is referred to as the
master drive. It controls a set of pumps each controlled by
a frequency converter or connected directly to mains
through a contactor or through a soft starter.
Each additional frequency converter in the system is
referred to as a follower drive. These frequency converters
do not need the cascade controller option card installed.
They are operated in open loop mode and receive their
speed reference from the master drive. The pumps
connected to these frequency converters are referred to as
variable speed pumps
Each additional pump connected to mains through a
contactor or through a soft starter is referred to as a fixed
speed pump.
Each pump, variable speed or fixed speed, responds to a
relay in the Master Drive. The frequency converter with the
Cascade Controller option card installed has five relays
available for controlling pumps. Two relays are standard in
the frequency converter and an additional 3 relays are
found on the option card MCO 101 or 8 relays and 7
digital inputs on option card MCO 102.
The difference between MCO 101 and MCO 102 is mainly
the number of optional relays being made available for the
frequency converter. When MCO 102 is installed, the relays
option card MCB 105 can be mounted in the B-slot.
The cascade controller can control a mix of variable speed
and fixed speed pumps. Possible configurations are
described in more detail in the next section. For simplicity
of description within this manual, pressure and flow are
used to describe the variable output of the set of pumps
controlled by the cascade controller.
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MG20Z102 - VLT is a registered Danfoss trademark
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