Baldor MN770 manual Inverter, 15H Control, 21H Control

Inverter	Series 15H	Inverter
	Series 21H	Inverter (Line Regenerative) IEEE-519 Compliant
	Typically Inverters are used in elevator applications where speeds up to 150 FPM are
	required.
	The Baldor inverter converts the three phase AC line power to fixed DC power. The DC
	power is then pulse width modulated into synthesized three phase AC line voltage for the
	motor.
	The rated horsepower of the control is based on a NEMA design B four pole motor and
	60Hz operation at nominal rated input voltage. If any other type of motor is used, the
	control should be sized to the motor using the rated output current of the control.
	Speed regulation of an Inverter Drive is dependant upon the slip of the AC induction
	motor. Typically this regulation will be 3% of base speed. Speed regulation can be
	increased to 1% of base speed by the addition of a DC tachometer for feedback.
	The output of the inverter is a Sinewave of current to the motor. The more pure the
	Sinewave is, the less additional heat produced in the AC induction motor. If a motor
	produces less heat, more torque is available to drive the load. The PWM control method
	produces less heat and gives a better approximation of a Sinewave of current to the
	motor when compared to a Six-Step type of inverter.
15H Control	The Baldor Series 15H control may be programmed to operate in one of four operating
	zones; standard constant torque, standard variable torque, quiet constant torque or quiet
	variable torque. For elevator applications, only the quiet constant torque or quiet variable
	torque modes are used. It can also be configured to function in a number of operating
	modes for custom operation. These choices are programmed using the keypad as
	explained in the programming section of this manual.
	Regenerated power from the motor is applied back to the DC bus and must be dissipated
	by REGEN Hardware (resistive load). The REGEN (or dynamic brake) hardware is
	selected based on the power to be dissipated. The amount of power, duration and
	frequency of the braking must be taken into consideration when sizing these resistors.
21H Control	The Series 21H Inverter is a line regenerative control. Regenerated power is applied
	back to the incoming power lines.

Regenerated power from the motor is applied to the incoming AC power lines. The Series 21H control meets IEEE 519 (1992) for total harmonic distortion. By returning the excess power back to the line, energy use is reduced for the building. The lower THD causes fewer power problems for sophisticated equipment on the same power grid. No external dynamic braking hardware is required.

MN770 Technologies 2-3