00:01
We're given a shunt motors application and asked to find its no load speed.
00:07
The key to solving this is understanding the relationship between the motors back, emf, speed, and flux.
00:18
So the first step is to calculate rated back emf.
00:24
So we have a rated armature current equal to or described as, call this ia rated rated rated is equal to, i sub l minus i sub f so this translates to the 55 amps minus the quantity of 240 volts divided into 109 .1 oms.
01:08
So we're dividing the voltage into the resistance to find the current and that's the function of oms law across a parallel circuit.
01:24
So then this difference yields 47 .6 ampires of rated armature current.
01:41
So the next step is to calculate the rated back emf.
01:48
So we can call this e sub a rated.
02:02
So we'll describe this as v sub t minus i sub a rated multiplied times rc.
02:20
Sub a, which translates to 240 volts minus 47 .6 amps times 0 .364 oms across that equation.
02:59
The yield is in voltage to 222 .8 volts...