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

operating at 40 °C ambient temperature. If battery packback-up fails, analog I/O option must be exchanged.3.1.9 Extended Cascade Controller MCO101 and Advanced CascadeController, MCO 102Cascade control is a common control system used tocontrol parallel pumps or fans in an energy efficient way.The cascade controller option provides the capability tocontrol multiple pumps configured in parallel in a way thatmakes them appear as a single larger pump.To satisfy the required system output for flow or pressurewhen using cascade controllers, the individual pumps areautomatically turned on (staged) and turned off (de-staged) as needed. The speed of pumps connected toVLT® AQUA Drive FC 202 is also controlled to provide acontinuous range of system output.Illustration 3.7 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. For simplicity of description withinthis manual, pressure and flow are used to describe thevariable output of the set of pumps controlled by thecascade controller.3.1.10 Extended Cascade Controller MCO101The MCO 101 option includes 3 pieces of change-overcontacts and can be fitted into option slot B.Maximum terminal load (AC) 240 V AC 2 AMaximum terminal load (DC) 24 V DC 1 AMinimum terminal load (DC) 5 V 10 mAMaximum switching rate at rated load/min load 6 min-1/20 s-1Table 3.11 Electrical DataWARNINGWarning Dual supplyNOTICEPlace the label on the LCP frame as shown (ULapproved).Selection Design Guide46 Danfoss A/S © Rev. 06/2014 All rights reserved. MG20Z20233