Toshiba VF-A7 Resolution, Calibrating a meter when the inverter is out of operation

[Terminal AM-related parameters]

Title	Function	Adjustment range	Default setting
	AM Terminal meter selection	Same as (: disabled)	
	AM Terminal meter adjustment	－	－

■Resolution

Both the terminals FM and AM have a maximum resolution of 1/1024.

★With the default settings, FM terminal outputs about 16 V (external impedance is infinity) or about 3mA (external impedance is 0 ohm), when running frequency is 80Hz. AM terminal outputs about 16 V or about 3mA, when the output current reading on the control panel is 150%

■Calibrating a meter when the inverter is out of operation

If it is difficult to calibrate a meter because of large fluctuations of its reading, you may put the inverter out of operation to make its calibration easier.

It is possible to adjust the meter for hte data item selected with the parameter  or . Refer to the table on the next page for the calibration procedure.

Adjustment level:

(a): The output voltage FM/AM-CC reaches 100% at the maximum frequency ().

(b): The output voltage at FM/AM-CC reaches 100% when the reading on the control panel is 150%.

(c): The output voltage at FM/AM-CC reaches 100% when the reading on the control panel is 100%.

(d): Special output (Refer to the instruction manual for the applicable device.)

(e): The output voltage at FM/AM-CC reaches 100% when the electric power is √3×200V(400V)×(inverter rated current).

[Example of the calibration of the frequency meter connected to the terminal FM-CC]

*Before proceeding to calibration, make the zero-adjustment of the meter itself.

Key operated,		LED display		Operation
	－		The running frequency is displayed.(If the monitor display
			mode setting  is set at [Running frequency])
	MON		Press the MON key to call up the first basic parameter
			 (automatic acceleration/deceleration).
▲	▼		Select  by pressing the △ or ▽ key.
	ENT		Press the Enter key to display the running frequency.
			Adjust the meter by pressing the △ or ▽ key.
			Note that the meter reading varies during adjustment,
			though the reading in the digital LED (monitor) on the
▲	▼		control panel does not change.
				[Point] Holding down the key for several
				seconds facilitates this adjustment.
			★By setup, before	the needle of meter begins to sway,
			it will take time.
	ENT		Press the Enter key to terminate the meter calibration.
		⇔	Then,  and the running frequency are displayed
			alternately.
	MON		Press the Monitor key to return to the running frequency
			display mode.(If the monitor display mode setting parameter
			 is set at [Running frequency])

★For meter connection, the VF-A7 inverter has two output terminals; FM and AM, which can be used simultaneously.

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