GE 469 Instruction Manual

Also see for Masoneilan 469 Series: Instruction manual Instruction manual Instruction manual Communications guide Instruction manual

Contents

S5 Thermal Model 469Motor Management RelaySetpointshttp://www.GEindustrial.com/multilin 5–39GE MultilinIf the motor is called upon to drive a high inertia load, it is quite possible andacceptable for the acceleration time to exceed the safe stall time (keeping in mindthat a locked rotor condition is different than an acceleration condition). In thisinstance, each distinct portion of the thermal limit curve must be known andprotection must be coordinated against that curve. The relay protecting the motormust be able to distinguish between a locked rotor condition, an acceleratingcondition, and a running condition. The Voltage Dependent Overload Curve featureis tailored to protect these types of motors. Voltage is continually monitored duringmotor starting and the acceleration thermal limit curve is adjusted accordingly.The Voltage Dependent Overload Curve is comprised of the three characteristicshapes of thermal limit curves as determined by the stall or locked rotor condition,acceleration, and running overload. The curve is constructed by entering a customcurve shape for the running overload protection curve. Next, a point must beentered for the acceleration protection curve at the point of intersection with thecustom curve, based on the minimum allowable starting voltage as defined by theminimum allowable line voltage. The locked rotor current and safe stall time mustalso be entered for that voltage. A second point of intersection must be entered for100% line voltage. Once again, the locked rotor current and the safe stall time mustbe entered, this time for 100% line voltage. The protection curve created from thesafe stall time and intersection point will be dynamic based on the measured linevoltage between the minimum allowable line voltage and the 100% line voltage.This method of protection inherently accounts for the change in motor speed as animpedance relay would. The change in impedance is reflected by motor terminalvoltage and line current. For any given speed at any given line voltage, there is onlyone value of line current.MESSAGE TIME TO TRIP AT6.50 x FLA: 8.5 sRange: 0.5 to 99999.9 s in steps of 0.1MESSAGE TIME TO TRIP AT7.00 x FLA: 7.3 sRange: 0.5 to 99999.9 s in steps of 0.1MESSAGE TIME TO TRIP AT7.50 x FLA: 6.3 sRange: 0.5 to 99999.9 s in steps of 0.1MESSAGE TIME TO TRIP AT8.00 x FLA: 5.6 sRange: 0.5 to 99999.9 s in steps of 0.1MESSAGE TIME TO TRIP AT10.0 x FLA: 5.6 sRange: 0.5 to 99999.9 s in steps of 0.1MESSAGE TIME TO TRIP AT15.0 x FLA: 5.6 sRange: 0.5 to 99999.9 s in steps of 0.1MESSAGE TIME TO TRIP AT20.0 x FLA: 5.6 sRange: 0.5 to 99999.9 s in steps of 0.1MESSAGE MINIMUM ALLOWABLELINE VOLTAGE: 80%Range: 70 to 95% in steps of 1MESSAGE STALL CURRENT @ MINVline: 4.80 x FLARange: 2.00 to 15.00 x FLA in steps of0.01MESSAGE SAFE STALL TIME @MIN Vline: 20.0 sRange: 0.5 to 999.9 s in steps of 0.1MESSAGE ACCEL. INTERSECT @MIN Vline: 3.80 x FLARange: 2.00 to STALL CURRENT @ MINVLINE – 0.01 in steps of 0.01MESSAGE STALL CURRENT @ 100%Vline: 6.00 x FLARange: 2.00 to 15.00 x FLA in steps of0.01MESSAGE SAFE STALL TIME @100% Vline: 10.0 sRange: 0.5 to 999.9 s in steps of 0.1MESSAGE ACCEL. INTERSECT @100% Vline: 5.00 x FLARange: 2.00 to STALL CURRENT @ MINVLINE – 0.01 in steps of 0.01