Danfoss VLT AQUA Drive FC 202 Design Manual

Also see for VLT AQUA Drive FC 202: Service guide Installation guide Installation guide Operating guide Installation guide

Contents

Illustration 3.12 Cascade Control of Multiple PumpsThe cascade controllers are optional hardware andsoftware components that can be added to the VLT®AQUA Drive FC 202. It consists of an option boardcontaining three relays that is installed in the B optionlocation on the drive. Once options are installed, theparameters to support the cascade controller functions areavailable through the control panel in parameter group 27-** Extended Cascade Control. The extended cascadecontroller offers more functionality than the basic cascadecontroller. It can be used to extend the basic cascade withthree relays and even to eight relays with the advancedcascade control card installed.While the cascade controller is designed for pumpingapplications and this document describes the cascadecontroller for this application, it is also possible to use thecascade controllers for any application requiring multiplemotors configured in parallel.Master/follower operationThe cascade controller software runs from a single VLTAQUA Drive with the cascade controller option cardinstalled. This frequency converter is referred to as themaster drive. It controls a set of pumps each controlled bya frequency converter or connected directly to mainsthrough a contactor or through a soft starter.Each additional frequency converter in the system isreferred to as a follower drive. These frequency convertersdo not need the cascade controller option card installed.They are operated in open loop mode and receive theirspeed reference from the master drive. The pumpsconnected to these frequency converters are referred to asvariable speed pumps.Each additional pump connected to mains through acontactor or through a soft starter is referred to as a fixedspeed pump.Each pump, variable speed or fixed speed, responds to arelay in the master drive. The frequency converter with thecascade controller option card installed has five relaysavailable for controlling pumps. Two relays are standard inthe frequency converter and an additional 3 relays arefound on the option card MCO 101 or 8 relays and 7digital inputs on option card MCO 102.The difference between MCO 101 and MCO 102 is mainlythe number of optional relays being made available for thefrequency converter. When MCO 102 is installed, the relaysoption card MCB 105 can be mounted in the B-slot.The cascade controller can control a mix of variable speedand fixed speed pumps. Possible configurations aredescribed in more detail in 3.6.9 General Description. Forsimplicity of description within this manual, pressure andflow are used to describe the variable output of the set ofpumps controlled by the cascade controller.3.6.9 General DescriptionThe cascade controller software runs from a single VLT®AQUA Drive FC 202 with the cascade controller optioncard installed. This frequency converter is referred to as themaster drive. It controls a set of pumps each controlled bya frequency converter or connected directly to mainsthrough a contactor or through a soft starter.Each additional frequency converter in the system isreferred to as a follower drive. These frequency convertersdo not need the cascade controller option card installed.They are operated in open loop mode and receive theirspeed reference from the master drive. The pumpsconnected to these frequency converters are referred to asvariable speed pumpsEach additional pump connected to mains through acontactor or through a soft starter is referred to as a fixedspeed pump.Each pump, variable speed or fixed speed, responds to arelay in the Master Drive. The frequency converter with theCascade Controller option card installed has five relaysavailable for controlling pumps. Two relays are standard inthe frequency converter and an additional 3 relays arefound on the option card MCO 101 or 8 relays and 7digital inputs on option card MCO 102.The difference between MCO 101 and MCO 102 is mainlythe number of optional relays being made available for thefrequency converter. When MCO 102 is installed, the relaysoption card MCB 105 can be mounted in the B-slot.The cascade controller can control a mix of variable speedand fixed speed pumps. Possible configurations aredescribed in more detail in the next section. For simplicityof description within this manual, pressure and flow areused to describe the variable output of the set of pumpscontrolled by the cascade controller.Selection VLT® AQUA Drive FC 202 Design GuideMG20Z102 - VLT® is a registered Danfoss trademark 613 3