3–30

“B” Group: Fine Tuning Functions

Configuring

Drive Parameters

 

 

 

 

“B” Function

Run

 

Defaults

 

 

 

 

 

 

 

 

 

 

Func.

Name /

 

 

Description

Mode

–FE

–FU

–FR

Units

 

 

Edit

Code

SRW Display

 

(CE)

(UL)

(Jpn)

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

B_86

Frequency scaling

 

Specify a constant to scale the

✘

1.0

1.0

1.0

—

 

conversion factor

 

displayed frequency for D_07

 

 

 

 

 

 

 

 

 

monitor, range is 0.1 to 99.9

 

 

 

 

 

 

/Hz01.0

0.00

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

B_87

STOP key enable

 

Select whether the STOP key

✘

00

00

00

—

 

 

 

 

on the keypad is enabled, two

 

 

 

 

 

 

STOP-SW

 

ON

 

 

 

 

 

 

 

option codes:

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

00 ...enabled

 

 

 

 

 

 

 

 

 

01 ...disabled

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

B_88: Restart Mode Configuration – You can configure how the inverter resumes motor output control after a free-run stop. Setting B_88 determines whether the inverter will ensure the motor always resumes at 0 Hz, or whether the motor resumes from its current coasting speed (also called frequency matching). The Run command may turn OFF briefly, allowing the motor to coast to a slower speed from which normal operation can resume.

In most applications a controlled deceleration is desirable. However, applications such as HVAC fan control will often use a free-run stop. This practice decreases dynamic stress on system components, prolonging system life. In this case, you will typically set B_88=01 in order to resume from the current speed after a free-run stop (see diagram below, right). Note that using the default setting, B_88=00, can cause trip events when the inverter attempts to force the load quickly to zero speed.

NOTE: Other events can cause (or be configured to cause) a free-run stop, such as power loss (see “Automatic Restart Mode” on page 3–22), or an intelligent input terminal [FRS] signal. If all free-run stop behavior is important to your application (such as HVAC), be sure to configure each event accordingly.

An additional parameter further configures all instances of a free-run stop. Parameter B_03, Retry Wait Time Before Motor Restart, sets the minimum time the inverter will free-run. For example, if B_03 = 4 seconds and the cause of the free-run-stop lasts

10 seconds, the inverter will free-run (coast) for a total of 14 seconds before driving the motor again.

 

B_88 = 00

Resume from 0Hz

 

B_88 = 01

Resume from current speed

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Zero-frequency start

 

 

 

 

 

 

 

 

 

 

 

B 03

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Motor

 

 

 

 

 

 

 

 

 

Motor

 

 

 

 

 

 

 

 

 

Wait time

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

speed

 

 

 

 

 

 

 

 

 

speed

 

 

 

 

 

 

 

 

 

 

 

 

[FRS]

 

 

 

 

 

 

 

 

 

[FRS]

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

[FW, RV]

 

 

 

 

 

 

 

 

[FW, RV]

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

t

 

 

 

 

 

 

 

 

 

 

 

 

 

t