Electricians out there?

[Ryunker]

Trying to get my lift running, it is 3 phase, I have a three phase converter. My hold up is I have a square D contactor and need to utilize it with a micro switch. This worked well years ago when I purchased the lift. Since then, well I have no clue how to wire it up?

 

[Bentworker]

I might know what I am doing with wiring...

More info / pictures?

 

[Don C]

Why the microswitch and what activates it?

What voltage/wattage is required for the coil on the contactor?

 

[Ryunker]

First photo is the microswitch, next is the contactor assembly, last is my two phase to three phase converter yet to be installed. Please help if you can. I understand the contactor to be like a relay, if thats true if I had info on where the microswitch ties into that, the rest I believe will work itself out.

 

[Ryunker]

Why the microswitch and what activates it?

What voltage/wattage is required for the coil on the contactor?

A lever down low activates the switch, I do not know the answer to the second question.

 

[Bentworker]

Okay- we’re entering liability territory.

In the photo you do not have a three phase converter.  That is a frequency drive.  Very cool - but it is going to take a bit more wiring as it needs to be directly wired to the motor.

Can you post the make / model of the lift and the frequency drive?  You are going to need instruction literature.

Wire the motor directly to the output of the frequency drive (try to keep the run short and in Flex metallic conduit for shielding). The micro switch (Maybe not???) will be wired to the control input of the frequency drive, and most likely you will have to program the drive to function with the microswitch. The power to the frequency drive needs to be fed through an over current device (breaker or fuse) and be connected to the frequency drive as shown in the instruction literature from the frequency drive manufacturer.

Putting it on a frequency drive is actually a pretty cool idea.  You can set up the frequency drive to start the motor slowly and ramp it up to speed.  

 

[Carolina_Mountain_Mustangs]

Hey I served a 10,000 hour apprenticeship in tool & die at Square D. I can build any tool you need to make the components but know nothing about that wiring, lol. Then I went to Cutler Hammer and worked 16 years and still did not learn how to wire except normal home stuff, lol.

 

[Don C]

You are correct, a contactor is a heavy duty relay. The input voltage for the coil should be shown on the label. Hopefully your phase converter is single phase to three phase. There are only a few cities on the east coast that still have 2 phase power available. Even though 240 volt systems have two hot leads they are single phase.

I'm assuming the microswitch acts as a limit switch to turn it off when the lift reaches bottom. In that case the limit switch will be connected to the controller. The contactor just provides power to the lift, and not up and down. It looks like the contactor is for 3 phase power, so it will be after the phase converter and before the lift controller. The lift controller should provide the power to actuate the contactor.

I'm with Bentworker, you really need the wiring diagrams for everything. Did the phase converter and contactor come with it as part of a package, or were they added on to make it work?

 

[rvrtrash]

A little trivia, just because. 240V is indeed two 120V sources, measured to ground, but they are 180 degrees out of phase with each other. That's how you get to 240V.

 

[Bentworker]

Figured I should follow up what I said earlier.  A lot of this will be in the manual for the frequency drive.

When using a frequency drive you CAN NOT put any sort of switch In the circuit from the frequency drive Output to the motor.  If you switch the output you risk destroying the frequency drive.
 

If frequency drives were not finicky you could just wire the output of the drive to the lift contactor and be good to go.  Unfortunately that IS NOT the case.  Whatever permissive devices previously made the contactor coil energize (limit switch + raise lever?) now must be Isolated and reconfigured to the inputs on the frequency drive.

Frequency drive always has power.

Frequency drive only outputs three phase power if the input tells it to.
 

The frequency drive takes the place of the contactor in a roundabout way.
 

Hope that makes sense.  If you want message me a number and time and I can call you.

 

[turtle5353]

Like Bentworker said, you need some wiring prints for this from the drive or manual. Most places do not have 3 phase power outside of large industrial applications. He is also correct that your 3rd pic is a VFD not a 3 phase converter. You dont want to wire it wrong and blow it up, they are not cheap. Are you positive this was wired for 3 phase originally? I have seen a contactor like that used on single phase 220 applications but only use 2 of the 3 poles.  The microswitch is probably a safety mechanism. Its a travel limit switch to prevent you from running the car up too high. They usually get wired into the control voltage side and shuts off the control input to the drive to prevent the lift from being run up too high. 

Although a drive seems a bit excessive for a lift. The stand alone contactor and microswitch would do everything needed on their own.  Definitely need  some more information. 

I work on overhead cranes for a living and they have all these same features and components. 

 

[rvrtrash]

Can I suggest a possible change in direction? My lift has a 240V motor and a push button to turn it on when I want it to go up. You might consider changing the motor and eliminating the VFD and contactor.

Steve

 

[Don C]

How a clear closeup picture of the motor data plate, so we can see what kind of motor you have and what size it is. Did all of the components you have come as part of a package?

While the VFD can also serve as a three phase converter the motor has to be able to handle the variable frequency speed control. 

Do you know what the input voltage for the VFD is supposed to be?

Please clean the lens on your phone so we can get some clear pictures and read model numbers and load requirements.

 

[Ryunker]

This was all working three phase when I purchased it a decade ago? I do not have three phase is why I purchased that vfd. It came with a manual, but have not gotten back to see if I could switch it there.

I really have no intention to go with a different style pump and switch as others suggested.

Probably be the weekend to get back at it, work gets in the way.

 

[turtle5353]

I have never seen a VFD used as a phase converter. I'm curious to see how that works.  Keep us posted. 

 

[Bentworker]

I have never seen a VFD used as a phase converter. I'm curious to see how that works.  Keep us posted. 

It works pretty good.  The VFD takes the single phase AC - rectifies it to DC then inverts it back to 3 phase AC at whatever frequency you want.  Many of the three phase input VFD's can operate off of single phase input but you have to de-rate them.  IE use a 5 hp drive on a 3 hp motor.  I have a 5hp three phase motor running off a VFD at home that is powered by a single phase 240V circuit.  It is actually pretty trick for speed control on machine tools and other things like band saws.  Not that expensive to do as long as long as the motor horsepower is low.  For something like a lift where it will be starting and running near max HP you cannot use a static phase converter (as they de-rate the motor's horsepower)  If you want full nameplate horsepower out of a three phase motor the two options are a rotary phase converter or a VFD.