The old field has 17 turns on each field. For a total of 34 turns for two
poles.
These two fields were wired in parallel. When you say "work out the total
amp turns"
Is that amp/turns per pole?
Since the two poles are is parallel that would be 1/2 times amp/turns or
(.5
x amps)/17turns
And, what wiring scheme should I use: all in series, all in parallel,
parallel
two and put in series with the other parallel two?
Thanks for your input, MikeK
Your reply is confusing, firstly you said you had a compound motor so
there should be two windings on each pole, series and shunt, you now
seem to have only one.
I'll try again.
I have a compound 4 pole motor. Two of the poles are series fields with
17 turns, these two are wired in parallel. The other two poles are shunt
fields
and wound with many (100s) of turns. These are wired in series.
Each pole has only one winding on it.
Secondly poles come in pairs, so a four pole
motor has 2 pole pairs, opposite each other.
This is correct.
Each pole pair needs to be considered as independent from the other
pole pair. Magneticaly the poles of a pair are in series so the amp turns
add up. eg: 17 turns at 1amp for each pole equals 34amp turns in total.
But, these are in parallel so the current is divided, that would make it,
1/2amp x 17turns x 2 poles = 17 amp-turns.
I think?
Someone on a forum suggested that shunt fields commonly have equal amp-turns
as the series field, so winding the new series fields the same as the
original would
give similar torque and rpm.
So, if I wire the two new 17 turn poles in parallel and put those in series
with
original two 17 turn parallel poles I should have 1/2 amp through each pole
of
17 turns, this equals 8.5 amp-turns. With 4 poles x 8.5 amp-turns I would
end
up with 34 amp-turns. I think this would be equal to the original series and
shunt fields as far as amp-turns.
What do you think?
Thanks, MikeK
