Yaskawa iQpump1000 AC Drive Quick Start - Manual (Page 185)

Related Parameters, Faults, and Alarms
No. Parameter Name Setting Values
P4-21 Low City Input Select
Default: 1
Range: 0, 1
P4-22 Low City On-Delay Time
Default: 10 s
Min.: 1
Max.: 1000
P4-23 Low City Off-Delay Time
Default: 5 s
Min.: 0
Max.: 1000
P4-24 Low City Alarm Text
Default: 0
Range: 0 to 2
H1 Multi-Function Digital Input Settings
H1-oo
Setting
Function Description
73 Low City Press
Indicates that sufficient or insufficient pressure is present on the inlet to the pump. Used mainly for pressure
booster situations.
HOA Keypad Display Minor Fault Name
Low City Pressure Low City Pressure
Cause Possible Solution
Insufficient pressure is present on the inlet
to the pump.
• Check pressure switch contact for correct operation.
• Check control wiring to drive terminal strip from pressure switch contact.
• Check to make sure that suction pressure is present by means of a separate measuring device.
HOA Keypad Display Minor Fault Name
Low Suction Pressure Low Suction Pressure
Cause Possible Solution
Insufficient suction pressure is present.
• Check pressure switch contact for correct operation.
• Check control wiring to drive terminal strip from pressure switch contact.
• Check to make sure that suction pressure is present by means of a separate measuring device.
HOA Keypad Display Minor Fault Name
Low Water in Tank Low Water in Tank
Cause Possible Solution
The water level in the tank is too low.
• Check pressure switch contact for correct operation.
• Check control wiring to drive terminal strip from pressure switch contact.
• Check to make sure that suction pressure is present by means of a separate measuring device.
n Current Limit
This function provides a current limit of the pump (motor). The function is designed to prevent long-term overload conditions
of the pump, especially if the motor and drive are oversized compared to the pump. The drive will attempt to limit the output
current by reducing the frequency reference. The frequency is reduced using an internal current PI regulator. When the Current
Limit function is active, the alarm "Current Limit Foldback" will be displayed on the HOA keypad. This function will only
operate correctly when the drive is connected to a variable torque motor load such as a centrifugal pump. More specifically,
it will only operate if the load is such that output current increases as output frequency increases (and vice-versa). The current
limit function reduces the pump speed to just above the lower value between the minimum pump speed (P1-06) or the minimum
output frequency. If PI mode is enabled (b5-01 > 0), a special limit will be applied to the PID integrator when output current
limit is active to prevent integrator wind-up.
Start Up Procedure
1.
Set all other parameters required for the application such as PI control loop, sleep, motor, and I/O parameters
2.
Turn on the current limit function by setting Q3-01 to 1 (enabled). The default setting is 0 (disabled).
3.
Set the desired current limit in Q3-02. This value should not exceed the motor, pump or drive’s ratings. This does not
in any way change the motor (oL1) and inverter (oL2) overload functions.
4.
If desired, program a multi-function digital output (H2-oo) to 89 (Output Current Limit) to annunciate the alarm.
4.5 iQpump Presets and Functions
YASKAWA TOEP YAIP1W 01B YASKAWA AC Drive - iQpump1000 Quick Start Guide 185
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Start-Up Programming & Operation