The successful range of Lenze SMV refrequency inverters with IP65 enclosure has now been extended with four new powers up to 22kW. Dimensions and costs have been kept low by the use of a cooling fan that maintains the high enclosure level. This in turn means that no panel space is needed, a very useful feature when upgrading existing machinery, but also reduced costs on new machine designs. The SMV has found wide acceptance in food production, bakery mixers, conveyors, pumps and vacuum compressors.
With totally enclosed inverters such as the SMV, there are two options to get rid of the heat losses within the drive – either make the drive physically bigger to convect the heat away, or use a cooling fan. Lenze have chosen the latter route specifying a fan that is IP65 protected. The result is compact dimensions, for example 470 high x 240 wide x 241 deep at 22kW, small even for an IP20 enclosed inverter.
Another feature of the SMV inverter is the EPM pluggable memory chip. This 10mm x 10mm module holds all the settings of the drive. For the machine manufacturer this means that drives can be programmed in seconds, offline using a hand held programmer. In the unlikely event of a failure in the field or a need to change settings, a memory chip can be despatched rather than to send an expensive Service Engineer.
A popular option for the SMV inverter is a lockable mains isolator. This can save further panel space and cost. Where simple speed control at the inverter is needed, another new option provides a potentiometer in the lower panel of the inverter. This is a retrofit option that is available for all powers. Where the inverter is to be mounted outdoors, a polycarbonate casing is available to eliminate problems of UV degradation. A wide range of field bus options can be added as communication modules, for example CANopen, PROFIBUS, Ethernet/IP and DeviceNet.
SMV inverters are available for single phase supply up to 2.2kW and from there with three phase supply up to 22kW. Three phase voltages of 400, 480 and 600 V are possible. At the other end of the supply range, a more unusual option has 120V supply with a built in voltage doubler. The inverters give highly responsive open loop sensorless vector control with 200% overload available for 15 seconds. Settings include adjustable ramps and S-curve profiles. Great flexibility is enhanced by worldwide approvals and the ability to operate in ambient temperatures from -10 to +50ºC.
The IP65 enclosure of the Lenze SMV frequency inverters can give significant cost savings on production machinery. As no panel protection is required, drives can be positioned at the process, reducing cable runs and eliminating the need for shielded cables. The memory chip allows programming in seconds, and the keypad or the optional potentiometer give easy control for operators. These advantages are now available from stock for powers between 0.25 and 22kW.
electrical industry inverter drives news, e-lec.org