single phase reversing contactor

[cjphelps]

Hello,

I have a single phase motor(230V) that can be made to forward/reverse by wiring according to this information:

CCW:
L1 --------------- P1
L2 --------------- T4 -T5
T2-T3-T8
P2

CW:
L1 --------------- P1
L2 --------------- T4 -T8
T2-T3-T5
P2

Can I do this with a reversing contactor, and a 3C cable?
The reversing cable I have has 7 poles, a 3pole with 1 aux, interlocked to another 3 pole.

help!!!!!!!!!

 

[cadpoint]

I sure hope someone throws in some diagrams and pictures , terminating on L2 sounds like a trip....:roll:

 

[brian john]

Assuming what you say is correct, I believe you can do this, But I would need to draw it out, scan it in and from home that ain't happening.

Someone else with better control drawing capabilities will chime in.

 

[gar]

080823-0927 EST

cjphelps:

It appears you want to swap T5 and T8 between L2 and T2. That requires a DPDT switch function and 4 wires.

If you had a 3 phase motor it would require 2 leads to be swapped to change direction and the same DPDT function.
.

 

[cjphelps]

Hi yeah its a single phase motor,

Can I do it with a starting contactor? (2 contacctors connected through interlock switch?
If so , I am still a little confused about how to wire it using a 3C cable.

 

[mdshunk]

Must you use a contactor? A drum switch will be cheaper, if you can use it.

 

[peter d]

Must you use a contactor? A drum switch will be cheaper, if you can use it.

Ya. Quite cheaper. $20 or $30 at Grainger. I had this issue when I need to wire up a lathe. Reversing starter or drum switch....hmmmm....tough choice.

 

[mdshunk]

Just looked at the wiring layout again... essentially all you're doing is moving T5 and T8 around to change rotation. Yeah, I'd use a drum switch if I could.

 

[peter d]

Yeah, I'd use a drum switch if I could.

As would I.

One major drawback to the drumswitch is that there is almost zero room for the conductors within the enclosure. It takes some careful make-up of the conductors, and sledgehammer to get the cover on.

 

[hillbilly1]

To reverse a single phase motor, the start winding is reversed, which according to the information given is T5 andT8. I would give you a drawing, but my drawing program uses too many bytes to post on this forum. Two three pole contactors are used, which are mechanically and electrically interlocked. (Thats what the auxillary contact is used for) The contactor is wired basically as a double throw switch, reversing the start winding depending which contactor is energized. They are expensive, expect to pay from $200 bucks and up depending on the size you need. Drum controllers are from $30 and up.

 

[jrannis]

If you saw the first Back to the Future move they used a drum switch to operate the flux capacitor in the car

 

[cjphelps]

i agree, but we already have the contactors set up.

I need to know how to resolve the logic of swapping T8 and T5 with L2 and the jumped wires, from my contactor side of the connection. Only 1 Contactor will be operatonal at a time(either forw/reverse mode)

better wiring specs needed on the motor:

FORWARD:

L1 --------------------------P1

L2--------------------------T4---T5

Join together T2-T3-T8

REVERSE:

L1 --------------------------P1

L2--------------------------T4---T8

Join together T2-T3-T5

 

[cjphelps]

To reverse a single phase motor, the start winding is reversed, which according to the information given is T5 andT8. I would give you a drawing, but my drawing program uses too many bytes to post on this forum. Two three pole contactors are used, which are mechanically and electrically interlocked. (Thats what the auxillary contact is used for) The contactor is wired basically as a double throw switch, reversing the start winding depending which contactor is energized. They are expensive, expect to pay from $200 bucks and up depending on the size you need. Drum controllers are from $30 and up.

Hi hillbilly,

yeah we actually already bought one with the interlock, and I am trying to figure out the switching logic at the contactors side?

 

[nakulak]

I believe this is the wiring for a two position 2x1p contactor, or two 2x1p individual contactors ? (make sure F/R switch is break before make)

 

[gar]

080823-1232 EST

cjphelps:

Do you know what a DPDT switch does? Following is a scheamatic of sorts:

     L2 --.----|A1 |--------------.------- T5
          |                       |
          |----|A1'|--------|     |
                            |     |
                            |     |
     T2 --.----|A2 |--------.------------- T8
          |                       |
          |----|A2'|--------------|


  A is a single relay with DPDT contacts or a DPDT switch.
  A1 is one of the two poles, and A2 is the other.
  A1  and A2 are normally open contacts, 
& A1' and A2' are normally closed contacts.

  If you have a 4 pole contactor with reversible contacts, then 
  re-label A1' as A3', and A2' as A4'

  The structure above -.- means there is a connection.
                       |

  The structure above  |  means no connection.
                      ---
                       |

 

[Smart $]

080823-1232 EST

cjphelps:

Do you know what a DPDT switch does? Following is a scheamatic of sorts:

     L2 --.----|A1 |--------------.------- T5
          |                       |
          |----|A1'|--------|     |
                            |     |
                            |     |
     T2 --.----|A2 |--------.------------- T8
          |                       |
          |----|A2'|--------------|


  A is a single relay with DPDT contacts or a DPDT switch.
  A1 is one of the two poles, and A2 is the other.
  A1  and A2 are normally open contacts, 
& A1' and A2' are normally closed contacts.

  If you have a 4 pole contactor with reversible contacts, then 
  re-label A1' as A3', and A2' as A4'

  The structure above -.- means there is a connection.
                       |

  The structure above  |  means no connection.
                      ---
                       |

My version...

Note this cannot be accomplished with two 3P (3 ? NO contacts) if the reversing contactors are also the starting contactors, where L1 is also switched, because [motor] T4 is directly connected to L2 and would remain energized in the "OFF" state. So either two 4P-NO contactors are necessary or one 2P-NO starter contactor and two 2P-NO reversing contactors.

PS: Five conductors need to be run between starter and motor.

cj, ...is there a separate starter contactor controlling L1, L2 for RUN?

 

[gar]

080823-1428 EST

Smart $:

Yours is a much nicer drawing than mine. Thanks.

.

 

[jim dungar]

These are diagrams for a split phase motor. There are two versions, one uses some of the factory jumpers (works better if using their overload relay) and the other home-built ones (has the line terminals on the top).

I took the diagrams for a drum switch and converted them to 3-pole contactors. It wasn't hard once I got rid of the idea of "line side and load side" of the contactors.

 

[LarryFine]

Do you know what a DPDT switch does?

What you drew is a DPDT switch with cross-connections to form a reversing switch. A typical 4-way switch does the same thing, and could be used as a manual reversing switch.

 

[ronaldrc]

I think this would work?