Lorch HT 180 AC DC : Fault code E3

[Weldoradoo]

Hi,
I own a Lorch Tig welder ( HT 180 AC DC) that has a fault code( E03). In the manual this fault code is listed as: Current sensor faulty. And the obigatory : Contact your nearest Lorch dealership :-/. Well is there a Lorch expert here, who can tell me what this fault means and how to solve it myself. The replacement part that is needed seems to be: Lorch 982.0939.0. "shunt 2pol microfit"

 

[Weldoradoo]

 

[matt1978]

Hello,

I see That your in the Netherlands. PM me your details and the serial number and I’ll put you in touch with a local Lorch agent.

 

[Weldoradoo]

Hi, just send me a repair manual for fault E03. I dont want to travel to some Lorch dealership. I know where they are. In my town is no Lorch agent anyway.

 

[Weldoradoo]

Serial Nr:

 

[Weldoradoo]

Serial Nr 731-1650-009

 

[Weldoradoo]

So I made a few pics. That this shunt could go bad seems impossible. The shunt measures the current to the plus Dinse socket. Maybe the red double wiring to X7 on Eprom Circuit board is broken. But then again why would this wire go bad ??

 

[matt1978]

Did you already try a master reset?

Disconnect the tig torch, then Press the Button for selecting DC or ACDC and the lower right hand button together for around 7 seconds. You should see the whole front panel light up, once this has happened you can release the buttons.

 

[Weldoradoo]

Yes i tried that. To no avail. I measured the Resistance of the red cable to Eprom circuit board (X7). The cable is just fine. The shunt is also not visibly broken.

 

[Weldoradoo]

Only possibility left would be the circuit board itself. Or am I missing something?

 

[matt1978]

Only possibility left would be the circuit board itself. Or am I missing something?

I don’t know as I’m not a service engineer.

The unit is 16 years old so it could be something like the PCB or something minor like a bad connection. I think it’s best that you take it to a service centre and let them diagnose the problem for you.

 

[Weldoradoo]

I give up. I have other welders that work just fine. I will keep it for parts. The only option would be used circuit boards. I will call some Lorch service centers if they have used parts.

 

[matt1978]

I give up. I have other welders that work just fine. I will keep it for parts. The only option would be used circuit boards. I will call some Lorch service centers if they have used parts.

I don’t know what else I can do for you. I priced up the part you asked me too, I gave you the info from the service manual relating to that error code.

I did say contacting a local agent would be the best way forward to begin with.

They may well find out it’s something stupid.

Did you buy it pre owned working or was it like that when you bought it?

 

[Weldoradoo]

I have the complete service manual myself. I checked the things that are listed there for Fault E03. Its an old machine, that did work fine until recently. Maybe its just over. I checked all connectors, cleaned them. Measured the cable. What else would a Lorch repair man do? Replace the PCB I guess. Only a used one would be affordable/ economic.

 

[Weldoradoo]

What is the part # of the Eprom 2 circuit board ? Considering my Serial Nr.

 

[eddie49]

You could do a basic go/no go test on the shunt by confirming that it has just about zero Ohms resistance across the two thin red wires, and then bolting the shunt into a circuit using the output of another of your welders. With a current flow of e.g. 50 Amps, you should be able to measure a few milliVolts ( up to 50 mV ) across the shunt.
You could also power-up the HT 180 welder with the voltage output of the shunt disconnected - plug X7 removed, and also with it replaced by a simple shorted wire, to see if the E03 error code changes.

 

[Weldoradoo]

Yes I already thought of just removing the X7 shunt connector. And see what would happen. But the shunt looks like factory new. How can a metal strip be broken? There is not even a tiny crack visible. Its just a whole piece of solid metal as far as I can see it. But I will try your tips.

 

[Weldoradoo]

Do all welders have a shunt current sensor like this? Whats its purpose? It already gives the fault code E3 without me welding or connecting a weld cable to the plus Dinse socket.

 

[Weldoradoo]

Its just this shunt inbetween. Cant I just fool the circuit board that its there?

 

[Jan-DIY]

Never seen such improvements in these machines.
Shunt error could be a problem in internal communication so first check adc bus.
Assuming it is connected to an FPGA.

Can be very tricky.