L2 momentary power loss ride-thru function – Yaskawa iQpump Controller Programming Manual User Manual

Page 117

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YASKAWA TM.iQp.07 iQpump Controller Programming Manual

117

L2 Momentary Power Loss Ride-thru Function

When momentary power loss recovery is enabled (L2-01

≠0), a speed search is executed to catch the potentially spinning motor shaft.

This speed search will occur regardless of the setting of b3-01 “Speed Search Selection”.

L2-01 Momentary Power Loss Detection Selection

L2-02 Momentary Power Loss Ride-Thru Time

Setting Range:

0.0 ~ 25.5 s

Factory Default: Model Dependent

The iQpump drive allows different responses to momentary power losses. The setting of L2-01 determines whether the iQpump drive
attempts to restart after a short loss of incoming AC power and for what length of time this capability remains active.

If L2-01 = “0: Disabled,” the iQpump drive detects a UV1 fault 15 ms after power loss and automatic restarting is disabled. The iQpump
drive cannot restart until the external run command is removed and the UV1 fault is reset.

If L2-01 = “1: PwrL Ride Thru t,” the iQpump drive restarts without the UV1 fault if power is returned within the time specified in L2-02,
the Momentary Power Loss Ride-thru Time. During the power loss but before the fault trip, the digital operator will display a UV alarm.
If L2-02 is set for a time longer than the control power supply can be sustained, a UV1 fault will not occur and the iQpump drive restarts
upon the return of AC power. The time that the control power supply can be maintained varies with iQpump drive size. The larger the
drive, the greater the potential ride-thru time.

If L2-01 = “2: CPU Power Active,” the iQpump drive ignores L2-02 and attempts a restart as long as the control power supply is still able
to maintain a minimal voltage level. In effect, setting L2-01 = “2: CPU Power Active” (factory default) is programming the iQpump drive
for maximum Power Loss Ride-thru. An equivalent setting is L2-01 = “1: PwrL Ride Thru t,” with L2-02 set to a time longer than the
control power supply can be maintained after power is lost.

Note: The run command must be held during power loss for any power loss ride-thru capability to be possible. It is for this

reason that 3-wire control is not recommended for use with the Momentary Power Loss function.

L2-03 Momentary Power Loss Minimum Baseblock Time

Setting Range:

0.1 ~ 5.0 s

Factory Default: Model Dependent

When momentary power loss recovery is enabled (L2-01

0) the iQpump drive will baseblock for a period of time specified by the L2-03

parameter. The baseblock time will be executed just prior to the speed search function in order to allow any residual magnetic fields in the
motor windings to decay before any new voltage is applied to the motor.

If the motor’s secondary circuit time constant is known, set L2-03 = 0.7x (value of time constant). If an OC or OV fault occurs during
momentary power loss recovery, increase the setting of L2-03.

The L2-03 parameter also sets the baseblock time for the DC Injection Braking function (b1-03 = “2: DC Injection to Stop”). If an OC or
OV fault occurs during DC Injection Braking to Stop, increase the setting of L2-03.

L2-04 Momentary Power Loss Voltage Recovery Ramp Time

Setting Range:

0.0 ~ 5.0 s

Factory Default: Model Dependent

When momentary power loss recovery is enabled (L2-01

≠0), a speed search is executed to catch the potentially spinning motor shaft. As

part of the speed search function full voltage is not immediately applied to the motor but is ramped up. The setting of parameter L2-04
determines the ramp time for increasing the output voltage from zero to maximum voltage (E1-05).

If a UV1 fault occurs during the current detection speed search function, increase the setting of L2-04.

Setting

Description

0

Disabled

1

PwrL Ride Thru t

2

CPU Power Active (

factory default

)

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