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wireing for rpc

racinjason

Aluminum
Joined
Sep 9, 2007
Location
coatesville indiana
i just got a 15 hp motor,it has a sepret set of wiring for starting. i was gona start it with a poney motor? will 1/2 hp work? so does this mean just wire it for the regular run curcuit? thanks Jason
 
It may be beneficial to post the nameplate data from the motor so folks have the same information you have. Your post makes no sense as to the seperate winding for starting.

If you have a 3 phase motor it has no start winding. It should be suitable for connection for high voltage (460 volts) or low voltage (230 volts) but these are the same windings just connected for the proper voltage. If it is not a dual voltage, 9 wire motor then it may not be suitable for a RPC. Post the nameplate info and we can see what it is.
 
more info

ok i have more info,its got 12 wires shows one way to hook it up to start and a second for run,im turning it with a pones motor so im figuring i dont need to use the start side

tag says for run 7 8 9
6 4 5
12 10 11
1 2 3

l1 l2 l3

i hooked all them up 7 6 12 1,8 4 10 2, 9 5 11 3. to l1 lo2 and l3. its a us motor 15 hp. this is the only motor i have with 12 wires,have wired up plenty 9 wire but this one has me stumped

jason
 
My Electrical Engineering Pocket Handbook shows for low voltage (240v), dual voltage motor, Y wound, 4,5,&6 joined, 10,11,&12 joined and 1,7; 2,8; 3,9 are the inputs. This is different than what you said the tag says. Can not find anything with that wiring configration. Typically, anytime only 1,2,&3 are the inputs, it's for 480v.
 
"My Electrical Engineering Pocket Handbook shows for low voltage (240v), dual voltage motor, Y wound, 4,5,&6 joined, 10,11,&12 joined and 1,7; 2,8; 3,9 are the inputs."

That is correct.

Clockwise from North, outside to inside.

1, 2, 3; 4, 5, 6; 7, 8, 9; 10, 11, 12.

A phase is 1---4, 7---10

B phase is 2---5, 8---11

C phase is 3---6, 9---12

If an internally connected "star point" is present, 10, 11 and 12 are internally connected and are not available externally.
 
Since your motor has 12 external leads, I would think it is a wye start / delta run connected motor. For lower voltage you would use the delta run connection
L1= 1,6,7,12
L2= 2,4,8,10
L3= 3,5,9,11
Now if you wanted to reduce your inrush current by 66%, you can use the wye start connection. After your idler motor is up to speed, the winding connection would have to be changed to delta run connection.
 
still confused

macplus yes thats the way i wired it,and yes it says y start and delta run,tried it and it did not like it,tried to switch 2 leades not knowing if that would mater once it is spining with the poney. i do not know for sure this motor works as i bought it used. thanks for the info ill have to research this a bit more

jason
 
Give me a few days, and I will post a diagram for wye start, delta run phase converter internal connections.
 
Perhaps some one with more first hand info will post with more info than I have. I tried one Delta run motor as a RPC and it would not work. I have had great success with Wye connected motors.
 
There should be no reason why a delta motor could not run off of a RPC. I would make sure that the delta motor was good and check to make sure it was wired up for a delta connection.
 
macplus, how do you switch from the wye to the delta after starting?

Here is the diagram for a 12 lead wye start / delta run RPC, with this setup you should be able to reduce the inrush current on the RPC around 66%
 

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MacPlus,

My comments about the delta connected motor concern using it as an idler. The one I tried would not work as an idler but will run just fine from 3 phase or from RPC generated 3 phase. I did not try a wye start / delta run so I have no idea how it will work.
 
Toolnut,
I wish I had a answer why that delta motor would not work as a idler motor. I do know that I have used RPC control panels on Leeson electric motors that were delta connected, and they worked great as a idler motor.
 
macplus, thanks for the diagram. I may play with wiring one later. A customer wants me to build a 60 hp converter and this may be a starting option. Otherwise I'll have to use a pony motor to get it up to speed.

I have built several Delta wound RPC's (mostly 20 & 30 hp's and one 7 1/2 hp) and all have worked well - the data plate said they were delta wound.

Question: If one has a 12 lead motor, can it be configured for either wye or delta. Or does one need to know which way it was wound for. One of the 40 hp converters I built, I first wired it delta, but it did not seem to like that so I changed it to wye and all was well. The delta's usually require less total capacitance to balance voltages.
 
I have never seen a 12 lead delta motor by itself. There are 12 lead wye motors and 12 lead wye start / delta run motors. This information is based on single speed motors.
 
I've been accumulating parts for a FW 10 hp. I have a 12 lead motor that i hope i can use. here is a very fuzzy picture of the wiring instructions. it says "For across the line start" and "for wye - delta start". I was going to hook it up as pictured in the upper left diagram. where could I read about wye/delta starting?
 

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