3–36

“B” Group: Fine Tuning Functions

Configuring

Drive Parameters

 

 

Miscellaneous Settings

The miscellaneous settings include scaling factors, initialization modes, and others. This section covers some of the most important settings you may need to configure.

B080: [AM] analog signal gain – This parameter allows you to scale the analog output [AM] relative to the monitored variable.

B082: Start frequency adjustment – When the inverter starts to run, the output frequency does not ramp from 0Hz. Instead, it steps directly to the start frequency (B082), and the ramp proceeds from upward there.

B083: Carrier frequency adjustment – The internal switching frequency of the inverter circuitry (also called the chopper frequency). It is called the carrier frequency because the lower AC output frequency of the inverter “rides” the carrier. The faint, high-pitched sound you hear when the inverter is in Run Mode is characteristic of switching power supplies in general. The carrier frequency is adjustable from 2.0 kHz to 14 kHz. The audible sound decreases at the higher frequencies, but RFI noise and leakage current may be increased. Refer to the specification derating curves in Chapter 1 to determine the maximum allowable carrier frequency setting for your particular inverter and environmental conditions.

NOTE: The carrier frequency setting must stay within specified limits for inverter-motor applications that must comply with particular regulatory agencies. For example, a European CE-approved application requires the inverter carrier to be less than 5 kHz.

B084, B085: Initialization codes – These functions allow you to restore the factory default settings. Please refer to “Restoring Factory Default Settings” on page 6–8.

B086: Frequency display scaling – You can convert the output frequency monitor on D001 to a scaled number (engineering units) monitored at function D007. For example, the motor may run a conveyor that is monitored in feet per minute. Use this formula:

Scaled output frequency (D_07) = Output frequency (D_01) ⋅ Factor (B_86)