Connection problem 2

[jammyjim]

Hi all


I have a 3 phase 4 pole winding, 3 leads out 400v its a fan motor, at first glance it looked like a 3 tier winding 4 groups per phase 12 singles 24 slots, top to top connection.

the problem is its actually 8 coils 2 tiers 16 slots 1-4 pitch, it actually looks like a single phase winding, but the name plate is clear 3 phase 4 poles 400v, i cant see how i can get 4 poles from this kind of coil configration, can anyone help??

 

[teco]

jammyjim :- sounds like you have a scott "t" connected motor. woods fan co use this type of motor for small aom fans. back coils are connected in series and the top winding connects to the center point of the back winding this forms a star point.
hope this helps
kind regds.

 

[edison123]

Teco,

That's interesting. First time, I've heard of scott t connected motor. Any websites that explain this kind of connection in motors ?

 

[teco]

jammyjim:- dont know of any web site however samuel heller shows examples of this connection in his book multispeed and standard squirrel cage motors vol 1 single speed. ref "the offset T circiut"
hope this helps
kind regds

 

[jbartos]

Suggestion: Please, post the motor nameplate data, if available.

 

[aolalde]

Please review the data provided, since 8 coils with span 1-4 do not match with 16 slots. Are some slots shared or empty? How many turns, wires, terminal leads had the original winding? Provide complete nameplate data, current, rpm, frequency, etc.

 

[jammyjim]

Thanks for all the replies peeps, havn`t got turns and wire size as yet, as i want to sort the connection before i detail the job further

Btw it is a Woods Fan motor and is 50 hz, aolalde, the info i gave in my original post is accurat 8 coils probably singles 1-4 span 16 slots, no shared or vacant slots and the winding is 2 layer with 3 leads out 4 poles,

Teco i have never seen a "t" connected motor, and am having trouble comprehending it, anymore info you could supply me with would be great, if anyone knows how to connect this winding, could you use the info below to help me

ie

left of group 1 = supply lead U
right of group 1 goes to right of group 4 (cross conn) etc

--- --- --- --- --- --- --- ---
1 2 3 4 5 6 7 8

 

[jammyjim]

btw, ill post full nameplate data tommorrow...

 

[jammyjim]

Here are all the details i could get from the nameplate


Make Woods
Voltage 400/440
Hz 50
1380 rpm
0.22 amps

 

[jbartos]

Suggestion: Visit

http://www.woods-fans.com

http://www.engnetglobal.com/search/brands.asp?startat=420&brandid=&search=&ch=&companyid=HVA001

for more info

 

[aolalde]

You have an unbalance in magnitude and angle 3-phase winding, with a number of slots not divisible by the number of phases.

The best option to get 4 poles, 3-phase is to connect it as a consequent pole with six ( 6) active groups and one dead coil. Note the dashes in each group show the coils in the group.

A1 - - - A2 B1 - - B2 C1 - - - C2
A3 - - A4 B3 - - - B4 C3 - - C4 “-“

For WYE 1 circuit:
T1=A1, T2=B1, T3=C1; jumpers A2&A3, B2&B3, C2&C3, neutral A4&B4&C4

For DELTA 1 circuit:
T1= A1&C4, T2=B1&A4, T3=C1&B4; jumpers A2&A3, B2&B3, C2&C3

Check flux densities to decide the connection and circuits.

 

[petestro]

jammyjim
if u still need connection drawing,i can provide.

 

[jammyjim]

Yes i still need that drawing if you have it petestro, thanks

 

[petestro]

leave your email address and i'll get it to you

 

[jammyjim]

llewelen@hotmail.com