Baldor mn722 Inverter Control Board Level 2 Parameter Definitions, Output Limits, Custom Units

Table 4-5 Inverter Control Board Level 2 Parameter Definitions

Block Title	Parameter	Description
OUTPUT LIMITS	Operating Zone	Sets the PWM operating zone to Standard 2.5KHz or Quiet 8.0KHz output carrier
		frequency. Two operating modes are also selectable: Constant Torque and Variable
		Torque.
		Constant Torque allows 170 - 200% for 3 seconds overload or 150% for 60 seconds
		overload.
		Variable Torque allows 115% peak overload for 60 seconds.
	MIN Output Speed	Sets the minimum motor speed in RPM. During operation, the motor speed will not be
		allowed to go below this value except for motor starts from 0 RPM or during dynamic
		braking to a stop.
	MAX Output Speed	Sets the maximum motor speed in RPM.
	PK Current Limit	The maximum output peak current to the motor. Values above 100% of the rated current
		are available depending upon the operating zone selected.
	PWM Frequency	The frequency that the output transistors are switched. PWM frequency is also referred
		to as “Carrier” frequency. PWM should be as low as possible to minimize stress on
		the output transistors and motor windings. It is recommended that the PWM
		frequency be set to approximately 15 times the maximum output frequency of the
		control. Ratios less than 15 will result in non-Sinusoidal current waveforms. See
		Figure 4-3.
	CUR Rate Limit	Limits the rate of torque change in response to a torque command.
CUSTOM UNITS	Decimal Places	The number of decimal places of the Output Rate display on the Keypad display. This
		value will be automatically reduced for large values. The output rate display is only
		available if the Value At Speed parameter value is non zero.
	Value At Speed	Sets the desired output rate per RPM of motor speed. Two numbers are displayed on
		the keypad display (separated by a slash “/”). The first number (left most) is the value
		you want the keypad to display at a specific motor speed. The second number (right
		most) is the motor RPM corresponding to the units in the first number. A decimal may
		be inserted into the left numbers by placing the flashing cursor over the up/down
		arrow and use the arrow keys.
	Units of Measure	Allows user specified units of measure to be displayed on the Output Rate display. Use
		the shift and arrow keys to scroll to the first and successive characters. If the
		character you want is not displayed, move the flashing cursor over the special
		up/down character arrow on the left side of the display. Use the up/down arrows and
		the shift key to scroll through all 9 character sets. Use the ENTER key to save your
		selection.
PROTECTION	Overload	Sets the protection mode to Fault (trip off during overload condition) or to Foldback
		(automatically reduce the output current below the continuous output level) during an
		overload. Foldback is the choice if continuous operation is desired. Fault will require
		the control be “Reset” manually or automatically after an overload.
		Note: The “Foldback” selection may not be available on some early versions of
		the software.
	External Trip	OFF - External Trip is Disabled.
		ON - External Trip is enabled. If a normally closed contact at J1-16 is opened, an
		External Trip fault will occur and cause the drive to shut down.

Local Enable INP

Following Error

Torque Proving

OFF - Ignores J1-8 input when in the “LOCAL” mode.

ON - Requires J1-8 input to be closed to enable the control when in the “LOCAL” mode.

This parameter determines if the control is to monitor the amount of following error that occurs in an application. Following Error is the programmable tolerance for the AT Speed Opto output as defined by the Level 1 Output block, AT Speed Band parameter. Operation outside the speed range will cause a fault and the drive will shut down.

When this parameter is set to ON the control measures output current in all three phases to the motor. If output current is unbalanced, the control will trip off generating a torque proving fault. In a hoist application, for example, this is useful to ensure that motor torque exists before the fail safe brake is released. “Drive On” output, if programmed, will not occur if torque proving fails.

4-18 Programming & Operation MN722