Has anyone else experienced pre-charge resistor fail in ABB ACS800 VFD's. Our particular model is 400 A 575 Volt. The pre-charge resistor is 3.3 ohms 65 watts and is always left in the circuit, under the assumption that the half wave rectifier diode that is in series with it will not be...
In UL 845 (Harmonized UL, ANCE and CSA LV MCC's Standars *US, Mexico & Canada*) states the following:
"5.3.1.2 In the United States, the supply rating of equipment that is marked to indicate it is suitable for use as service equipment, has provision for 2 watt-hour meters without provision for...
Has anyone experienced tripping of a magnetic overload protector in a 2 speed motor starter when switching from low to high speed. The units in question have a 3 pole contactor for low speed and a 5 pole contactor for high speed.
This is a new installation with new contactors and motors...
An existing centrifugal water pump requires 3458 lb-ft of torque at 100% speed (1182 rpm)
It's WR^2 is 215 lb-ft^2
It is presently operated by a 900 HP, solid shaft, 1185 rpm (6pole) vertical induction motor. 4000V, 3 phase, SF 1.15
Present starting method, across the line, utility...
