I am trying to understand if Underexcitation limiter (UEL) is functional if the voltage regulator is set to manual mode when connected to a large system. By functional, I mean if the UEL will enforce the excitation limit when in manual mode. My understanding is that if the Automatic Voltage...
How does one set the stopped state cooling time of an induction motor without the datasheet providing that value? In some digital relays, there is a running cooling time (or rather running time constant entry), and also a separate entry for stopped cooling time. Since the shaft-connected fan or...
I understand that the Service Factor of the motor is the multiplier above the nameplate HP up to which the motor is rated for a continuous running capability -- my question is, technically how is this continuous capability limit defined and what exactly changes when the motor exceeds nameplate...
In the BH curve - H (the magnetic field strength) is in ampere turns per meter. If I keep the magnetic path length constant, H can be varied by varying the current. However, I want to make sure I understand this correctly - is current on the X axis of the BH curve referring only to the...
My understanding is that at no load, a transformer does have a certain no-load flux in the core, due to the magnetizing current in the branch. When it is loaded, the secondary draws more current, create an opposing flux (Lenz's law) that opposes the primary flux - and this inturn reduces the...
First, as per the attached picture in the link, a cross-compound unit with two generators is shown, and one is shown to rotate at 3600 rpm, while the other is at 1800 rpm.
1. Does the number of poles vary in each generator so as to produce the same frequency?
2. Why is it recommended (from...
Is an Induction motor considered to be operating at Service Factor 1.0 if it is operating at rated kW output but at 90% rated voltage with 111% of the rated full-load current?
In page 2 in the second paragraph from the link, the author discusses this, but I am not clear as to what the author...
