Schneider Electric 58 TRX User Manual

09/2003

©

 2000–2003 Schneider Electric All Rights Reserved

The pump switching option card can control a complete pumping installation 
using a single ATV58 TRX drive controller. It provides:

• Constant pressure in the system whatever the flow rate

• A simple method for installing and diagnosing the installation using the 

ATV58 TRX drive controller

The pump switching option card can operate up to four fixed speed pumps 
and one variable speed pump (the variable speed pump cannot provide the 
full flow range required on its own). A PI regulator is used for drive control and 
a pressure sensor is required to provide system feedback.

To prevent uneven wear of the pumps, the card allows pump switching 
according to operating time. The variable speed pump can be included in the 
swapping procedure.

Application Example (with 3 auxiliary pumps and one variable pump)

In this example, the auxiliary pumps are switched on and off according to the 
flow rate required by the installation. The variable pump is controlled to 
compensate for any flow rate variations.

The ATV58 drive controller controls the pumps via logic outputs DO1, DO2, 
DO3 etc., depending on the operating mode programmed. 

The logic inputs indicate the state of the pumps. 

• If LI = 1, the pump is ready to start and used in the automatic sequencing.

• If LI = 0, the pump is not ready and will not be used in the automatic 

sequencing.

Internal elapsed timers are used to keep track of the accumulated operating 
time of each pump. 

2

3

1

0

4

Control of auxiliary pumps

card

Number of pumps required

Flow rate
demand

PV: variable pump
P1, P2, P3: auxiliary pumps
M, M1, M2, M3: motors

Flow rate at 
constant 
pressure

Pressure 
measurement

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