FINALLY! Here we go again.
I ended above with the single pump setup using the internal setpoint controller.
Now we are going on to control multiple pumps. The drive can control as many as six pumps with option cards installed but, in standard configuration, it will control up to four. Let's use four to keep it simple. Also, we are going to assume one variable speed and three across the line with mag starters. That's usually called lead/lag.
Turn to page 49 in the instruction manual. This is the PFC macro or Pump and Fan Control. Notice that it is set up like the PID macro except that the bottom relay is labeled "Auxiliary Motor Switch". This would be a single extra motor as in a total of two pumps. A change in the software would reconfigure the relays so there would be two auxiliary motors as in a total of three pumps or three auxiliaries for a total of four.
Notice that on pin 15 (DI3) we have the speed regulator/PID selector. I am going to proceed assuming that this is jumpered to +24V so we are in PID mode.
At the bottom of page 63 is the PFC Group parameter summary with the detailed descriptions on page 136.
Starting in right at the first parameter 8103, 8104, and 8105 provide a little additional amount to the setpoint reference each time an additional pump is added to the system. These are not often used and default to zero.
Parameters 8109, 8110, and 8111 set the frequency of the variable speed motor which, if the motor operates there for a set amount of time, the next auxiliary pump will be started. These are typically set to the same frequency around 60Hz and the time is typically 10 seconds. To add auxiliary pumps, the drive picks up one of its output relays which pilots a mag starter on the extra motors.
Parameters 8112, 8113, and 8114 set the low speed on the variable speed motor which, if it operates there on dropping demand for a set number of seconds, the drive will drop out one of its output relays which drops out one of the starters on the auxiliary pumps.
Each time the drive adds or subtracts a motor, the PID loop senses the change and changes the variable speed motor to compensate for the addition or loss of the auxiliary pump.
The pickup and dropout delays are set at 8115 and 8116.
8117 is where you tell the drive how many motors you have in the system. Read this material carefully as it is the heart and soul of the Leag/Lag system. It also provides a nice diagram of the Lead/Lag with Rotation (or Autochange as they call it!).
I'm going to stop here to see that everyone is with me at this point.
If you've got questions, now is a good time to ask them.