Operating instructions

INSTALLATION
01 Jan 14 3-15
DE-7200VFDCentrifuge
BOWL, CONVEYOR, AND FEED PUMP MOTOR CONNECTIONS
The bowl and conveyor drive motors require three-phase VFD power and ground connections.
Power is derived through connections to terminal blocks inside the control cabinet. Similarly, the
customer’s feed pump motor must be connected to the centrifuge control system for control of its
operation.
Connect the bowl, conveyor, and feed pump motors to terminal blocks in the bottom left side of
the control cabinet as shown in Figure 3-14. The control system can operate a feed pump drive
motor of up to 30HP.
Figure 3-14. Electric Power Connections to Bowl, Conveyor, and Pump Motors
TANK LEVEL SWITCH CONNECTIONS
Tank level switches may be connected to the pump and bowl VFDs to prevent the pump from
being started when fluid in the tank falls below a predetermined level. Two normally open float
switches can be used to detect high and low tank levels. The switches may be placed at the
desired levels to permit the pump to operate under automatic PLC control within the designated
window set by the switch positions. The only requirement is to place the high level switch above
the low level switch. For hazardous locations, refer to the electrical schematic diagram in Section
8 for intrinsic barrier kit information.
During centrifuge operation, whenever the tank level is above the low switch position, the pump is
enabled by the closed low level switch. When the tank level rises sufficiently to close the high
level switch, the pump will cycle on and then off once the low level switch opens.
The low level switch is connected to the feed pump VFD through terminal block TB1 (Figure 3-
15), which is located to the left of the Ethernet switch. Depending on cabinet wiring, either
terminals 1 and 2 or 7 and 8 are used for the connections. The high level switch is connected to
the bowl VFD either through terminals 3 and 4 or 9 and 10.