Chapter 4 Parameters
VFD-EL-W 
4-93 
 
1: Fixed time circulation (alternative operation) 
2: Fixed quantity control (multi-pump operating at constant pressure) 
  When using the multi-pump control mode, you must set Pr.10.35 for each pump to the same value. 
 
10.36 
Multi-pump ID 
  Settings  0–4 
0: Multi-pump control mode is disabled 
1: Master 
2–4: Slave 
Default: 0
  When using the multi-pump control mode, the settings of each pump for Pr.10.36 cannot be the same. 
 
10.37 
Multi-pump’s Fixed Time Circulation Period  
  Settings  1–65535 minutes  Default: 60
  This parameter is only valid for master pump settings. 
  Fixed time circulation mode (alternative operation): Assume that when pump #1’s operating time is longer 
than the setting for Pr.10.37, pump #1 stops, and then pump #2 activates, and so on.  
  Fixed quantity control (multi-pump operating at constant pressure): Assume that when the master pump’s 
operating time is longer than the setting for Pr.10.37, the master pump and the slave pump switch 
alternatively.  
 
10.38 
Frequency to Start Switching Pumps 
  Settings  0.00 Hz–F
MAX
  Default: 60.00
 
10.39 
Time Detected When Pump Reaches the Starting Frequency 
  Settings  0.0–3600.0 sec.  Default: 1.0
 
10.40 
Frequency to Stop Switching Pumps 
  Settings  0.00 Hz–F
MAX
  Default: 48.00
 
10.41 
Time Detected When Pump Reaches the Stopping Frequency  
  Settings  0.0–3600.0 sec.  Default: 1.0
  This parameter is only valid for master pump settings. 
  This parameter is only valid for fixed quantity control (multi-pump operating at constant pressure) mode. 
  When the master pump’s operating frequency ≥ Pr.10.38, and the time exceeds Pr.10.39, slave pump #1 
activates. If the quantity of water is still insufficient, slave pump #2 and #3 activates under the same 
conditions. 
  If the master pump’s operating frequency ≤ Pr.10.40, and the time exceeds Pr.01.41, slave pump #1 stops. 
If the master pump can fulfill the conditions, slave pump #2 and #3 stop in sequence, and leave the master 
pump in operation only.  
  Whether the master pump stops depends on the stopping detection function. 
 
10.42 
Pump’s Frequency at Time-out (Disconnection) 
  Settings  0.00 Hz–F
MAX
  Default: 0.00
  This parameter is only valid for slave pump settings. 
  For details on the conditions of communication disconnection and treatment, refer to Pr.09.02 
Transmission Fault Action and Pr.09.03 Time-out Detection.  
  If disconnection (time-out) occurs in the fixed quantity control (multi-pump operating at constant pressure) 
mode, the frequency for the slave pump is Pr.10.42. When you press the STOP key, the disconnected 
slave pump is in single-pump mode. (The RUN command and operating frequency is set by the parameter 
settings for the slave pump.) 
  The master pump can re-detect the disconnection of the salve pump.