Geared motors

Accessories 8200 motecBraking operation8200 motec – Braking operation with brake resistorExternal brake resistors are required to brake highmoments of inertia or for extended generator mode operation.The brake resistor converts mechanical braking energyinto heat.The brake resistor integrated into the 8200 motec frequencyinverter activates the external brake resistor if the DCSelection of brake resistorsThe Lenze brake resistors recommended in the tables areappropriate for each frequency inverter (based on 150 %regenerative power). They are suitable for most applications.bus voltage exceeds the switching threshold. This preventsthe frequency inverter setting a pulse inhibit due to the"Overvoltage" fault and the drive coasting. Braking isalways controlled when using an external brake resistor.For specific applications, e.g. for centrifuges, hoists, etc., thesuitable brake resistor must meet the following criteria:Brake resistorApplicationCriteria With active load With passive loadContinuous brakingt 1≥ P max · e · m ·≥ P max · e · m t 1power [W] ·t cycl 2 t cyclThermal capacity [Ws]Resistance [Ω)≥ P max · e · m · t 1 ≥ P max · e · m ·t12R min ≤ R ≤U DC2P max · e · mActive loadPassive loadU DC [V]P max [W] e mt 1 [s]t cycl [s]Can be set in motion independently of the drive(e.g. hoists, unwinders)Will be brought to a standstill independently of the drive(e.g. horizontal motion drives, centrifuges, fans)Switching threshold, brake transistorMaximum braking power defined by the applicationElectrical efficiency (controller + motor)Guide value: 0.54 (0.25 kW) … 0.85 (11 kW)Mechanical efficiency (gearbox, machine)Braking timeCycle time = Time between two consecutive braking operations (= t1 + rest time)Brake resistors for the 8200 motec are supplied with high degrees of protection in order that they can be installed outsidethe control cabinet. This means that expensive HVAC units do not have to be installed to dissipate resulting power lossesfrom the control cabinet.9G-motion motec en 11/20049-69