YASKAWA iQpump1000 User Manual page 196

4.6 iQpump Presets and Functions
u
2-Motor Contactor Alternation
Parameter P4-14 enables and disables the 2-motor contactor alternation function.
This function allows one drive to power two motors in an "OR" configuration to evenly distribute the amount of wear on each
motor/pump.
Note: 1. This function is available in drive software versions PRG: 8552 and later.
2. Not available in drive models 4A0930 and 4A1200.
n
2-Motor Alternation Disabled (P4-14 = 0)
Setting P4-14 to 0 disables 2-motor alternation, clears all timers associated with the 2-motor alternation function, and de-
energizes digital output H2-0o = 43.
n 2-Motor Alternation Enabled (P4-14 = 1)
Setting P4-14 to 1 enables the 2-motor alternation function. The drive de-energizes digital output H2-0o = 43 to force the
relay/contactor logic to connect the first motor to the drive output terminals.
The alternation timer runs when the drive applies power to the motor (i.e., running, non-zero speed, not baseblocked). The
drive switches to the second motor when the timer reaches the time entered in P4-16, Alternation Time, depending on the
setting of P4-15, Two Motor Alternation Operation Selection.
If P4-15 is set to 0 (Wait For Stop), the drive will continue to operate on Motor 1 until the drive would normally go to zero
speed (zero reference, sleep mode, remove run command, fault). When the drive stops, digital output H2-0o = 43 energizes
so the drive will run motor 2 when it restarts.
If P4-15 is set to 1 (Immediate) and the drive is operating in Auto Mode when the alternation timer reaches the time set in
P4-16, the drive will immediately stop using the selected stopping method (b1-03). When the drive stops, When the drive
stops, digital output H2-0o = 43 energizes and the drive will restart and ramp back to speed after the minimum baseblock
time.
If the drive is operating in Hand Mode when the alternation timer reaches the time set in P4-16, the will continue to operate
on Motor 1 until the drive would normally go to zero speed (zero reference, sleep mode, remove run command, fault). When
the drive stops, digital output H2-0o = 43 energizes so the drive will run motor 2 when it restarts.
The alternation timer restarts after the digital output switches to drive Motor 2. The drive switches back to Motor 1 depending
on the setting of P4-15 after sufficient time passes with the drive running that the alternation timer reaches the P4-16 level.
The alternation timer and motor selection are stored to EEPROM when power is removed. Changing parameter P4-14 clears
the internal alternation timer and the alternation time stored in EEPROM..
P4-14 special considerations:
• Motor 1 is used first when P4-14 changes from 0 to 1
• Motor 2 is used first when P4-14 changes from 2 to 1
• Motor 1 is used first when P4-14 changes from 3 to 1
n Motor 1 Only (P4-14 = 2)
Setting P4-14 to 2 disables the 2-motor alternation function, clears all timers associated with the 2-motor alternation function,
and de-energizes digital output H2-0o = 43.
n Motor 2 Only (P4-14 = 3)
Setting P4-14 to 3 disables the 2-motor alternation function is disabled, clears all timers associated with the 2-motor alternation
function, and energizes digital output H2-0o = 43.
n Interaction with Sequence Timer (S2-oo)
Setting the sequence Selection (S2-04, S2-09, S2-14, S2-19) to 3, No Alternation, prevents 2-motor alternation during the time
set in the corresponding Sequence Timer. Alternation resumes normally when the timer deactivates.
Note: The Alternation Time set in P4-16 will run during the No Alternation time window. The timer will request for alternation after the No
Alternation time window is over if the timer expires.
196 YASKAWA TOEP YAIP1W 01F YASKAWA AC Drive - iQpump1000 User Manual