4.3.6 Fixed Variable Speed Pump Wiring DiagramL1/L2/L3 L1/L2/L3 L1/L2/L3Power SectionRELAY 1RELAY 2130BA376.10Illustration 4.12 Fixed Variable Speed Pump Wiring Diagram4.3.7 Lead Pump Alternation WiringDiagram130BA377.13L1/L2/L3FCL1/L2/L3 L1/L2/L3k3k2k3k1K2K1K1 K1K4 K3K4K3R1R2Illustration 4.13 Lead Pump Alternation Wiring DiagramEvery pump must be connected to 2 contactors (K1/K2 andK3/K4) with a mechanical interlock. Thermal relays or othermotor protection devices must be applied according tolocal regulation and/or individual demands.• Relay 1 (R1) and Relay 2 (R2) are the built-inrelays in the frequency converter.• When all relays are de-energised, the first built-inrelay that is energised cuts in the contactorcorresponding to the pump controlled by therelay. For example, Relay 1 cuts in contactor K1,which becomes the lead pump.• K1 blocks for K2 via the mechanical interlock,preventing mains from being connected to theoutput of the frequency converter (via K1).• Auxiliary break contact on K1 prevents K3 fromcutting in.• Relay 2 controls contactor K4 for on/off control ofthe fixed speed pump.• At alternation, both relays de-energise and nowRelay 2 is energised as the first relay.For a detailed description of commissioning for mixedpump and master/slave applications, refer to VLT® CascadeController Options MCO 101/102 Operating Instructions.4.3.8 External Alarm ResetParametersFC+24 V+24 VD IND IND INCOMD IND IND IND IN+10 VA INA INCOMA OUTCOM12131819202729323337505354554239130BB682.10Function Setting5-11 Terminal 19Digital Input[1] Reset* = Default valueNotes/comments:D IN 37 is an option.Table 4.6 External Alarm ResetApplication Examples Design Guide106 Danfoss A/S © 09/2014 All rights reserved. MG20N60244
