Replacing a Remote Switch

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Little Bill

Little Bill

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I was at a machine shop and the owner asked me to see if I could help or repair a remote switch. The switch operates a portable lift, similar to a crane, that lifts/lowers parts into a cleaning machine. The switch has up, high & low, down, high and low. It seems the mfg is no longer in business and a replacement switch couldn't be found.
Does anyone know how something could be fabricated or constructed to mimic the actions of this switch. I don't know the exact current draw but the machine runs on 240V. In case my earlier description isn't clear, I will try to show what the actions are.
Lifting something up - 1 button for low speed, 1 button for high speed
Lowering something down - 1 button for low speed, 1 button for high speed

This switch is connected by a SO or SOW cord from the switch to the machine motor. Whatever is used to replace it would need to be on the cord the same way for portability.
Thoughts?
 
I would think just a 4-button control box/station and install push-buttons. I'd imagine the controls are operating contactors or power relays and not handling the full load of the machine, though it would be good to confirm that.

1629896788636.png
 
I was there for another reason and didn't have time to do much looking. I have asked the guy to send me the nameplate info and picture of the switch. I'll post that when I receive it.
 
I also recommend buying the pre-fab ones, the box is designed to be ergonomic so that it doesn’t slip out of the hand of the operator. I used to use this outfit, they were good quality components.

Push Button Pendants | United States of America

www.conductix.us www.conductix.us

Hubbell has a crane control division too, they bought what used to be the old Square D crane controls before Schneider bought them so it’s the old NEMA grade stuff.

Pushbuttons and Pendants | Hubbell Industrial Controls (ICD)

Discover our selection of Pushbuttons and Pendants. Our product experts are here to assist you. Get in touch with our team now.
www.hubbell.com www.hubbell.com
 
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You should be able to add contact blocks to the push button operators as you need, just have to go through all the existing blocks to see what you need, and as you probably already know, document where each wire goes. Are all of the push buttons momentary? Or a mixture of both momentary and maintained?
 
I don’t think I have ever seen maintained push buttons used for hoist control, I would think that would be dangerous. But I have seen where there is a maintained selector switch for choosing Up or Down prior to pushing the Fast or Slow button.
 
Jraef said:
I don’t think I have ever seen maintained push buttons used for hoist control, I would think that would be dangerous. But I have seen where there is a maintained selector switch for choosing Up or Down prior to pushing the Fast or Slow button.
Click to expand...
It may be for the speed control, not the actual movement of the hoist, it also may be mechanically interlocked where low and high speed cannot be engaged at the same time. Too little of info to give a clear answer.
 
Jraef said:
I don’t think I have ever seen maintained push buttons used for hoist control, I would think that would be dangerous. But I have seen where there is a maintained selector switch for choosing Up or Down prior to pushing the Fast or Slow button.
Click to expand...

We had a crane with a button that could be rotated for Fwd/Rev, then pressed to actually move. The press function was momentary, of course. I have no idea how the contacts were positioned on the actuator to work that way??
 
Little Bill said:
I got some pics of the controller and motor. The controller still works, it's just the cover is busted off.


Click to expand...
yeah, definitely not getting any parts for that! Surprised that small of HP motor is three phase! Is there a starter/reversing contactor seperate from that? Or are they doing line voltage through the hand held controller?
 
hillbilly1 said:
yeah, definitely not getting any parts for that! Surprised that small of HP motor is three phase! Is there a starter/reversing contactor seperate from that? Or are they doing line voltage through the hand held controller?
Click to expand...

I'm not sure but I would think there would be some type of control or gear box. I do have a little more info on how the pendant works. There is supposed to be two buttons, (I thought it was 4) marked "up" and "down". When you lightly push either button it goes in the direction indicated in low speed, then push it all the way down and it goes into high speed. So theses are definitely momentary switches.
 
A suggestion is to disconnect the spade connectors and measure the continuity between the different switch terminals for all of the switch states: 1.) no button pushed, 2.) UP button partially pushed, 3.) UP fully pushed, 4.) DOWN partially pushed, 5.) DOWN fully pushed.
Then you can see if one of the following pendants on pg. 7 of the document at the link below could be wired to provide this fuctionality. This document is from the website that Jraef provided.

34296...2-Speed, 4NO, w/interlock
34297...2-Speed, Double Contact, 2NC, 4NO, w/interlock
34298...2-Speed, Double Contact, 2NC, 2NO x 2 w/interlock (Late Break)

https://www.conductix.us/sites/default/files/downloads/Manual_-_Push_Button_Pendants_80_Series.pdf
 
That has 3 momentary microswitches in there, and it looks like the wires go to the normally open contacts. The silver metal plate likely pivots and acts as the interlock to prevent pressing both outer switches (up/down) at the same time. The middle one is probably the fast/slow one.
/mike
 
If you go the replacement route, a bit of advice: the "SO" cable to the pendant likely has a steel aircraft strength member inside that takes the tugging of the pendant much better than the copper conductors. That aircraft cable will absolutely mangle the jaws of a normal electrical cable cutter, being steel. Ask me how I know...

You need a snips specifically designed for aircraft cable to get through it; Felco C7 or C19 are good choices. A lineman's pliers won't do much but make a mess either.



SceneryDriver
 
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