Help needed with component identity

LesJones

Joined Jan 8, 2017
4,511
Your pictures confirm that Ylli's theory about the resistor is correct. The fact that the resistor has fallen off will NOT stop the welder from working.
I will try to get you to answer a question that has been asked before but you have refused to answer. DO YOU HAVE A MULTIMETER EITHER ANALOGUE OR DIGITAL ? Without knowing that we do not know the best way to suggest how to help you find the fault. Can you confirm that when you press the trigger that the wire feeds but there is now voltage at the torch ?

Edit. I have just seen post #59. If you do have a multimeter with the welder NOT CONNECTED TO THE MAINS measure the resistance between terminals 42 and 44 on the contactor.

Les.
 
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Thread Starter

Gary swift

Joined Mar 27, 2019
21
Your pictures confirm that Ylli's theory about the resistor is correct. The fact that the resistor has fallen off will NOT stop the welder from working.
I will try to get you to answer a question that has been asked before but you have refused to answer. DO YOU HAVE A MULTIMETER EITHER ANALOGUE OR DIGITAL ? Without knowing that we do not know the best way to suggest how to help you find the fault. Can you confirm that when you press the trigger that the wire feeds but there is now voltage at the torch ?

Edit. I have just seen post #59. If you do have a multimeter with the welder NOT CONNECTED TO THE MAINS measure the resistance between terminals 42 and 44 on the contactor.

Les.
I do have a multi meter it’s a fluke
 

Thread Starter

Gary swift

Joined Mar 27, 2019
21
Your pictures confirm that Ylli's theory about the resistor is correct. The fact that the resistor has fallen off will NOT stop the welder from working.
I will try to get you to answer a question that has been asked before but you have refused to answer. DO YOU HAVE A MULTIMETER EITHER ANALOGUE OR DIGITAL ? Without knowing that we do not know the best way to suggest how to help you find the fault. Can you confirm that when you press the trigger that the wire feeds but there is now voltage at the torch ?

Edit. I have just seen post #59. If you do have a multimeter with the welder NOT CONNECTED TO THE MAINS measure the resistance between terminals 42 and 44 on the contactor.

Les.
There is no resistance Gary .
 

LesJones

Joined Jan 8, 2017
4,511
What do you mean by no resistance ? Zero ohms or infinity (Greater than 20 megohms ?) I suspect you mean infinity as most meters would read the resistance of the test leads if they here shorted together. If it is either of those values it has an open circuit or short circuit coil. I would expect the resistance to be in the order of hundreds or thousands of ohms.

Les.
 

Tonyr1084

Joined Sep 24, 2015
9,744
f a resistor that size is not supported and there is some lead length then it can vibrate and the copper conductors break.
There's even engineering that goes into mounting components and the amount of lead length. In earthquakes (a huge source of vibration) much engineering goes into the height of a building. They say an 8 to 10 story building will resonate at what is very often the resonant frequency of most earthquakes. Buildings that tall suffer more damage than much taller buildings because at that height they go into resonance, which amplifies the forces. Same is true of lead length. When standing a resistor off a board in a high vibration setting there is a specific height for that length that would result in fracture and failure, and is to be avoided.

If you've ever seen resistors that are mounted to a board where the lead loops UP before going down, into and through the board is done for two reasons, vibration being one of them. The other may be due to hole spacing and component body might not allow sufficient stress relief when the lead bends immediately out of the component; which is an IPC and J-Standard reject.

A component that large (your broken resistor) may be vibrating at a resonant frequency due to the fan vibrating. It may have been a smooth operating fan at one time but with dust buildup on the blades, they can start to vibrate. Also available are spring clips that mount to something solid, and the resistor is stuck between the two clips. It DOES interfere with some of the air flow through the middle, but if the resistor is large enough it shouldn't pose a problem.

What I might do if this were my project would be to find an appropriately rated resistor with an aluminum body and mount it to a heatsink and run wires from that mounted resistor to the point where it was connected. Looking closely at your broken resistor, it looks like the leads may be oxidized. You may have to sand the oxidation off in order to get a good connection. At this point you're beating an old nag (horse). It's going to die soon enough. Sanding the leads may hasten the demise. That's why I'd go with an aluminum resistor mounted to a heatsink. Or even just to the metal cabinet along with some good thermal grease.
 

Tonyr1084

Joined Sep 24, 2015
9,744
Proper way to read a digital meter on ohms setting: Turn it to ohms (yes, I know you're smart enough to know that - just follow me please). Don't connect the leads to anything. The display should show "OL" which can stand for "Over Limit" or "Open Line", I never quite chased that rabbit. In other words, it's showing there is more resistance than it can read. Approaching infinity. Next, you short the test leads together. Typical meters will drop down and show you a resistance value of 0.02 to 0.5 ohms. Doesn't have to be exactly those numbers, but this is showing there is a dead short (the leads touching). I've seen people call both conditions "No resistance". Many of us have. That's why we ask you to be very precise. Lack of precision can lead us to the wrong conclusion. When you say there's no resistance, many of us will assume the resistor is an open circuit. Some may conclude there is nearly zero resistance, akin to a short circuit. Short circuits are not bad things in some cases. In the case of a precision resistor (yours is not likely a precision) you might have a resistance of 0.1Ω, the likes of such precision MOST common meters can not measure accurately. I've seen resistances as low as 0.01Ω. Yes, that's a resistor, and the purpose of such a low resistance is beyond my understanding. Nevertheless, I've seen it. At least I think I recall seeing them that low.

Anyway, clarity is very important.

I would expect the resistance to be in the order of hundreds or thousands of ohms.
Here's another issue for me (at least for me, maybe I missed something). Are we talking about the resistor or the contactor? Or something else? I was thinking the resistor itself is around 20 ohms. I've come to that thinking by calculations and some assumed values. Again, assumed values means lack of clarity. And I'd readily admit when I don't know something.
 

Wolframore

Joined Jan 21, 2019
2,619
I was looking at the huge rectifier in the innards. Welders vibrate all of mine do. I believe it’s from the current. You can hear and feel it. 50-180 amps is a lot of power
 

Ylli

Joined Nov 13, 2015
1,092
OK, the TS has a DMM and a non-operative MIG welder. The resistor in question is a safety device and should not affect the actual operation of the unit. The wire feed appears to work, so the Control Board is getting power - however, the main contactor is not pulling in. With the gas enabled and the mode set to 'Stitch', when you activate the unit does the gas valve open? If it does, the problem is the main contactor or beyond. If the gas valve does not open, then the problem is Control Board related.
 
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killivolt

Joined Jan 10, 2010
836
Post # 53 max said, mount it his way, order the appropriate resistor and secure it, by the way is that R1 in parallel with a relay? if so you have eddy current hum from the relay.

kv
 

Thread Starter

Gary swift

Joined Mar 27, 2019
21
What do you mean by no resistance ? Zero ohms or infinity (Greater than 20 megohms ?) I suspect you mean infinity as most meters would read the resistance of the test leads if they here shorted together. If it is either of those values it has an open circuit or short circuit coil. I would expect the resistance to be in the order of hundreds or thousands of ohms.

Les.
There is no reading there turn meter on it says O.L connect to 42-44 stays O.L
 

Thread Starter

Gary swift

Joined Mar 27, 2019
21
OK, the TS has a DMM and a non-operative MIG welder. The resistor in question is a safety device and should not affect the actual operation of the unit. The wire feed appears to work, so the Control Board is getting power - however, the main contactor is not pulling in. With the gas enabled and the mode set to 'Stitch', when you activate the unit does the gas valve open? If it does, the problem is the main contactor or beyond. If the gas valve does not open, then the problem is Control Board related.
Like I say I get wire feed and gas when I pull the trigger
 

Ylli

Joined Nov 13, 2015
1,092
If the gas valve opens, but the main contactor does not close, then there is an issue with the main contactor. Physically examine it and confirm there is nothing mechanically interfering with it to prevent it from closing.

Can you locate the connections to the contactor coil? If so, set your DMM to read AC Volts and connect it across the coil terminals. Operate the welder and note if you get an AC voltage reading. Use caution as this should be 220 VAC.

If you do see 220 VAC, but no contactor movement.... Set the gas flow to DISABLED. Be sure all power is off and measure the RESISTANCE between the contactor coil connections. Would expect a couple hundred ohms.
 

LesJones

Joined Jan 8, 2017
4,511
Hi Max,
42 & 44 are the ends of the contactor coil. (From the schematic on page 14 of the manual in the link I posted in post #55) My preferred test would have been for him to measure the voltage between those terminals when the trigger was pulled but he is very much a beginer with electrical things I decided it was probably not safe to suggest doing that. The contactor coil is fed via a relay on the PCB from the 220 volt tap on the small transformer primary.

Les.
 

Ylli

Joined Nov 13, 2015
1,092
[Sorry LJ, didn't mean to step on your instructions. I also did not see 'terminals 42 & 44' and didn't know what you were trying to do].
 

LesJones

Joined Jan 8, 2017
4,511
Hi Ylli,
It;s not a problem. I nearly did the same thing yesterday on this thread. I scrolled back through this thread to check something and noticed that you had already said what I was typing in. I think we are just thinking about thsi problem in the same way.

Les.
 
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