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  #11  
Old 12-31-2017, 09:36 PM
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MetalWolf MetalWolf is offline
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Ok Thanks guys ......ill prolly use something else...
if anyone needs them let me know they are available....
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  #12  
Old 01-01-2018, 04:17 AM
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Quote:
Originally Posted by terry lingle View Post
You might want to know how much current the switch will be interupting to be sure that it is operating within it's range. If the current is too high you will need to add a suitable magnetic contactor to handle the load current.
Terry are you referring to one of these contactors like ones used in residential
HVAC...? here's a pic.
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Thanks........ Randall
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  #13  
Old 01-01-2018, 11:42 AM
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terry lingle terry lingle is offline
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Yes that is the concept.
The contact rating on the contactor must be more that the current needed by the load device for reasonable life expectancy.
The contactor coil voltage is matched to what is available in the circuit.
The switch now sees only the coil current which will be within it's capacity.
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  #14  
Old 01-01-2018, 12:49 PM
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Quote:
Originally Posted by terry lingle View Post
Yes that is the concept.
The contact rating on the contactor must be more that the current needed by the load device for reasonable life expectancy.
The contactor coil voltage is matched to what is available in the circuit.
The switch now sees only the coil current which will be within it's capacity.
I'm not sure how to wire it in but ill get my brother to do it he is a HVAC teacher for the gov. so i would assume he will know how its done correctly

Thanks Terry..... much appreciated help......Randall
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  #15  
Old 01-01-2018, 01:48 PM
Norcal Norcal is offline
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Limit switches are generally pilot duty devices, not intended to directly control the load, but to switch other devices such as relays, contactors, etc., that do control the load.
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  #16  
Old 01-01-2018, 02:41 PM
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Default wire diagram help needed

Ok so I called my brother and I'm not sure if he's just being a horses ass or what but he says i cant do that with a contactor but does not understand what I'm trying to do ....

So here is what i want to do i want to use the limit switch pictured with the contactor pictured as a means to put 230v to my spot welder when the limit switch actuates

can anyone make a wiring diagram for me as he keeps saying what does the schematic show and i don't know how to explain it to him and the more i try to explain what I'm doing he gets agitated cause i don't know squat about this type of wiring

i thought was or would be fairly simple..

so if someone can draw me a diagram maybe he can understand what it is i need wired and how it needs to be wired.

he wants to know voltage amps to limit switch and to contactor and out of contactor coil voltage.
just maybe it will be simple enough i can do it my self and need not bother him with it....

sometimes i just get to flustered to clearly think when i get stumped, I do appreciate any help an advise that can be offered.

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  #17  
Old 01-01-2018, 02:58 PM
Samcord Samcord is online now
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Do you have the specs for the contactor?
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  #18  
Old 01-01-2018, 03:01 PM
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A diagram is easy but more information is needed to make sure it will work.

1 voltage to run the welder
2 max current to the welder
3 coil voltage of the contactor

Spot welders normally close the jaws apply pressure then turn on the current.
This means that the current flow through the contacts is high so it is better to use a higher current rated contactor than the rated current for the welder.
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  #19  
Old 01-01-2018, 03:13 PM
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GWIZ GWIZ is offline
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Quote:
Originally Posted by MetalWolf View Post
Ok so I called my brother and I'm not sure if he's just being a horses ass or what but he says i cant do that with a contactor but does not understand what I'm trying to do ....
In other words he does not know what a Spot welder is.........

My first issue is does this need a timer, spot welders don't like a lot of on time.
spot welders can range something like 15 amps input and ~6000 amps output ..... contactor likely goes on the input/line side (not going to handle 6k amps).

Post a model number of the HF spot welder.
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Last edited by GWIZ; 01-01-2018 at 03:20 PM.
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  #20  
Old 01-01-2018, 03:21 PM
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Scotts Scotts is offline
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Do you have the contractor yet?

On the contractor you have pictured the specs should be printed on the side.

You need amps of your spot welder.

Imagine your hvac the limit switch will take the place of thermostat the spot welder will take the place of the compressor.

The units I have run into at homes usually have 24 volts for controls. That adds a little more complication to the controls.

Scott


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