single phase motor hook up 3

[excal103]

I have a 3 phase Square D Type S motor starter w/integral low voltage control panel, with forward and reverse contactors. I need to hook a Baldor 5Hp single phase motor with forward and reverse control.
For forward operation motor leads are: Line A 1,8 _ Line B 4 _ and tied Together J,5.
For reverse operation Motor leads are: Line A 1,5 _ Line B 4 _ tied together J,8.
How could the motor leads be wired to the to the forward and reverse contactors?

 

[dtracy03]

Hook up the leads to T1 and T3 on each of the contactors for forward and reverse but the contactors should be mechanically interlocked.

 

[excal103]

The explanation fails to explain the proper lead wires of the motor to hook to T1 and T3

 

[Barry1961]

I can see a way to do it if you can run the neutral (B,4?) straight to the motor.
This would involve running leads 1 and J to the top or line side of starter. Not sure if this is kosher so you better wait for an answer from someone who knows for sure.

1 J L1 1 J L1
= = = = = =
8 5 8 5 8 5

Of course all like wires are jumped together.

Just a thought.

Barry

 

[SteveKW]

If this is what you have...

http://www.baldor.com/products/drawing_files/pdf/CD0152.pdf

You won't be able to use your existing contactors!

You will need something like this...

http://grainger.com/Grainger/productdetail.jsp?xi=xi&ItemId=1611704589&ccitem=

Of course this example is too small for your motor!

 

[excal103]

Still need for imformation

 

[skiier]

Just a couple of questions.
What voltage is this single phase motor?
I am assuming this is at least a 240Vac motor?
A 5HP, 120Vac draws about 50A while a 240Vac motor draws about 1/2 that at 25A. A 5HP 3 phase motor draws about 15A at 240Vac. What I am getting at is that for a given HP rating the single phase contactor will always be bigger. The size increase is to accomadate more current and larger wires. So when you go to connect a single phase load to a 3 phase contactor you must be sure the contactor is rated for the load. A 5HP 3 phase conatctor may only be good for say 2HP for the same single phase voltage rating. Another problem is that you may not be able to match an overload unit to the contactor you have. The current rating being beyond the range of your contactor. Will your #10, or worse yet, your #6 wire even fit in a terminal on your contactor?

Let's say all the ratings are ok.

If your contactors are 4 pole and interlocked then you are ok.

Since Line B is always connected to ter.4 then you only have to switch the remaining leads. I sketched a drawing but i don't know how best convey it to you. It can be done quite simply.
You have a pencil? Draw 8 contacts on a page left to right. Label contacts left to right, 1 to 8. Top of contact is A, bottom of contact is B. Contacts 1 to 4 are "rev" starter, contacts 5 to 8 are "fwd" starter. This is strictly for the motor wiring not the control. I assume you can handle that?
Connect/JUMPER as follows;
1A TO 2A,
3A TO 4A TO 7A TO 8A TO LINE A,
5A TO 6A,
1B TO 7B TO MOTOR TER.8,
2B TO 6B TO MOTOR TER.J,
3B TO 5B TO MOTOR TER.5,
4B TO 8B TO MOTOR TER.1,
LINE B TO MOTOR TER.4.

Happy motoring.

skiier

 

[SteveKW]

Skiir...

LINE B TO MOTOR TER.4.

Is there no code/safety concern in leaving a motor lead across the line all the time?

 

[skiier]

Not as long as you fuse the conductor properly.
A disconnect for operator safety and fuse all ungrounded conductors. All code as far as I know. I guess your system is 240vac?
Equipment manufacturers do this all the time. A/C unit compressors, washing machines, dryers you name it. You think your the first to do such a connection arrangement?
Leaving one lead live means that the motor will always have a potential to ground. This may possibly reduce the insulation life of the motor. With the contactors you have what else are u going to do?

Did you manage to draw a diagram from my directions? I am eager to know if my instructiona were easy to follow.

Skiier

 

[SteveKW]

Skiir...

"A/C unit compressors, washing machines, dryers"

Can you give an example where the motor is external to the unit?

 

[resqcapt19]

Steve,
430.84 in the NEC says that the motor controller "shall not be required to open all conductors to the motor." Only the motor disconnect is required to open all of the ungrounded conductors. The controller only has to open the number of conductors required to cause the motor to stop.
Don

 

[excal103]

I'm not sure whether this will work or not but it looks good
5Hp 1 phase 230V 23A Size 1 starters
Wires off of motor are: 1,4,5,8,J

Reverse direction:
Line A: wires #1,#5
Line B: wire #4,
Joined: #J,#8

Froward direction:
LineA: wires #1,#8
LineB: wire #4
Joined #J,#5

Reverse Froward
L1 L2 1 J L1 L2 1 J
. . . . . . . .
A - - - - C - - - -
B - - - - D - - - -
. . . . . . . .
1 4 5 8 1 4 8 5

Jumper AL1 to CL1
Jumper AL2 to CL2
Jumper A1 to B1
Jumper B1 to D1
Jumper D1 to C1 D1 to motor
Jumper B4 to D4 D4 to motor
Jumper B5 to D5 D5 to motor
Jumper B8 to D8 D8 to motor
Jumper Aj to CJ CJ to motor