Maker Pro
Maker Pro

Help repairing power lift

dmccoyks

Sep 26, 2017
23
Joined
Sep 26, 2017
Messages
23
I got the number EB2011 from the picture you posted so I assume it's what you want.

Good luck.
Okay, where does it show that number? I don't see it on the board. Thanks

Never mind I see it now engraved on the switch. Should have looked closer. Sorry
 

Tha fios agaibh

Aug 11, 2014
2,252
Joined
Aug 11, 2014
Messages
2,252
Yep, Just make sure the normally open pin of the switch is at the top when you insert it.
 

73's de Edd

Aug 21, 2015
3,613
Joined
Aug 21, 2015
Messages
3,613
Sir dmccoyks . . . .

Indeed . . . . the specified 2011 switch given by our Right Honorable and Esteemed . . . .Tha fios agaibh . . . is being the proper one to use, as your referenced unit was using a shaft collar that was geared to solder mounting to a PCB.
The use of your same type of threaded shaft is required.
Also that switch that you initially referenced would have needed a jumper wire between the YELLOW end terminal and the center terminal, since switch common is being at the YELLOW end of the three terminals.
The Tha fios (I see) specified relay has the required center common terminal.
I have marked the blow up below to specify the RED and BLUE pairs of terminals that you would want to orient the switches N.O. contacts to, and use for each switch install.

FAILURE ANALYSIS:

In looking at my supplied bottom pic of the aspects of the control box . . . . .
Examining the stick on label of the control box, there is the high probability that the build of this unit ( with the adjunct visibility blocking effect upon the up down arrows) was altered from initially using the common supplied miniature hex nuts to mount the switches.
They modified it upwards by the use of a protective threaded metal sleeve / shroud to give aditional lateral impact protection to the switch shafts.

Somewhere in the lifetime of this unit . . .logically it being recent . . . their might have been an accident which led up to your end predicament.
Look at one of the left sides of one of those just mentioned protective sleeves and you can see impact dingy-dingies, where the whole system seems to have made hard contact with the concrete.

These lift units can use different base mounts so that the whole systen can be transferred between different vehicles. Possibly that somewhat weighty unit got dropped in one of those transfers ?

A caused secondary effect, I can see, would be the related hard pressure inwards on the two pushbuttons.
Look at my right bottom corner pic of the end of the switch portions of an old switch and you can see the 4 tang tabs that are pressed into divots recessed in the plastic molding to unite the plastic to the metal portions of the switch. I think that impact likely splayed the tabs apart and loosened them.
Then you come along an give a firm to hefty press on the switch button and the loosened tangs then slip along the side of the plastic and separate from the plastic and leave the contacts loose and the compression spring of the switch shaft being unable to let the switch pop back.

Thereby . . .your final situation.

Back to the switch, I believe that the old switches and the proposed new switch units inter terminal solder lug spacings are being the same . . .Perhaps your acuity in visual measurment has declined from possibly discriminating between a presumed .125 in and an actual 5/32nds in.
If it indeed requires some hole alterations, looks like a mini rat tail jewelers / tool and die file is needed.

The reason for the NEC POWER RELAY data sheet is so that you can see its LIKE MANNER of utilization, as is being shown in the second pages top corner illustration. Your switches contacts are merely supplying the minute power needed for the coils at 2-3 or 6-7.
The actual POWER switching actions within the relay proper, will flip the polarity of the voltage being sent to the drive motor to switch direction, that differentiates between lift or lower action.
Looks like the hole plugs on the housing and the extra paths on the PCB also tell us that there is being another upgrade and a motor that provides a power rotation of the boom, fo people that might need that extra assistance. . . .OOOOMPH.

SUGGESTION . . . .
While you are at it why not fabricate a metal barrier as I have being shown on only one of the switches in GREEN.
The switch screw on sleeves or separate screw sets can hold it down.
It is physically being about 3/4 " in width or greater and extends in its overall height as to be ABOVE the end heights of the switch buttons. Round the corners off from having any sharp corners. Use 1/8 in thick steel or even thicker aluminum ( thus requiring the screws, since the thread length of the switch shafts would be inadequate.)
You then have a sacrifical barrier for your switches mechanical protection .


Photo Assists . . . .

Lift Switch Info.png

73's de Edd
 
Last edited:

dmccoyks

Sep 26, 2017
23
Joined
Sep 26, 2017
Messages
23
Thank you very much for the very detailed and precise explanation. I agree that the switch was probably impacted during a fall. I usually keep it sitting up in my garage when not in use and I believe it fell down on the side with the switches. I will have to find a better solution for storing so it cannot fall down.

I should have the switches in next couple days and will let you all know how it turns out. I really appreciate everyone's time and help with fixing this issue and saving me time and money of getting it repaired.
 

Tha fios agaibh

Aug 11, 2014
2,252
Joined
Aug 11, 2014
Messages
2,252
Great post 73's de Edd.
Not a bad suggestion about about fabricating a protective bracket but it may not be necessary if the switch mounting nuts are installed correctly so that the shaft height is minimally exposed.

If the shaft sits too high (because nut under the mounting plate is missing or too low) the shaft can travel too far down when pushed and the bottom of switch gets blown out from the force).

So try to adjust the nuts so the button portion is only slightly raised above the surface. That way the switch should stay intact even if it takes a hard hit.
 

dmccoyks

Sep 26, 2017
23
Joined
Sep 26, 2017
Messages
23
My lift is fixed and working great. Thanks again for all your time and great help!
 
Top