Bell & Gossett P2002379A User Manual

INSTRUCTION MANUAL

Duty-Standby Pumps
Alternation

Table of Contents

Operation.........................................................................................................................................2

Duty-standby pumps alternation...............................................................................................2

Drive connections diagram........................................................................................................3

Parameter values......................................................................................................................... 4

Table of Contents

Duty-Standby Pumps Alternation INSTRUCTION MANUAL 1

Operation

Operation

Duty-standby pumps alternation

Drives can be set up to operate two pumps running alternatively to provide a reliable
pumping system. This helps to extend the life of pumps, energy conservation, and reduce
maintenance costs.

1. The Master drive and Slave drive use Setup 3 and Setup 4 to operate the alternation
operation.

2. To enable the alternation, set the parameter 13–00 SL Controller Mode in the Master
drive to On or vice versa.

3. The Master drive will control the alternation operation:
a) Timed alternation: Alternation timing is determined by Timer 0 in the parameter

13–20.0 SL Controller Timer in the Master drive. Changing this timer changes the
alternation timing.

b) Manual alternation: Pressing the [OK] and [>] keys on the Master drive at the same

time resets the alternation timer and alternate the drives for running the pump.

c) If the Off key of the Master drive is pressed, both drives stop the pumps.
d) If the Off key of the Slave drive is pressed, the Master drive continuously runs the

pump.

e) If any drive loses power or is stopped due to an alarm condition, the lag pump

automatically starts and continuously operates.

f) If the Hand on key in each drive is pressed, the drives run their own pumps

independently.

4. Refer to the wiring diagram for the wiring connection between the Master and Slave
drives.

5. The alternation process is performed as follows:
a) At start-up and in normal condition, the State Controller of the Master drive starts

in Setup 3 and runs its pump while the Slave drive starts in Setup 4 and stops its
pump due to input high received from the Master drive.

b) When the Timer 0 expires, the Master drive changes to Setup 4 and stops its

pump. At this time the input to the slave is low, the Slave drive changes to Setup 3,
and runs its own pump.

c) When the [OK] and [>] keys on the Master drive are pressed at the same time, the

Timer 0 is reset and alternates the drives.

d) When the Master or Slave drive is powered off or gets in an alarm condition, it

sends a low output signal to the other drive for changing the drive’s setup to
Setup 3 to run its own pump.

e) When the Master drive is in the Off mode, the Master drive stops and sends a high

output signal to the Slave drive to stop the slave pump.

f) When the slave is in the Off mode, it sends a low output signal to the Master drive

for running the Master pump.

2 Duty-Standby Pumps Alternation INSTRUCTION MANUAL