• Welcome to our site! Electro Tech is an online community (with over 170,000 members) who enjoy talking about and building electronic circuits, projects and gadgets. To participate you need to register. Registration is free. Click here to register now.

No output power (welding current or auxiliary power

Panagioite

New Member
Hi, I just signed on, have a Lincoln Ranger 10,000 plus, Kohler 23hp eng. runs good 350 hrs. Was Tig welding, lost all power, welding and auxiliary, Any ideas? Brushes are new, brass rings good, ?? Am in PNG end of the world.
Thank you,
Peter
 

dr pepper

Well-Known Member
Most Helpful Member
Presumable the motor still runs.
Check for any blown fuses.
And for any wires rubbed through and shorted.
Is there a contactor for the weld current, does it pull in?
 

Les Jones

Well-Known Member
Most Helpful Member
From the information in the service manual there are separate winding for welding and AC output power so I would check that the rotor was being energised.. You could first check the resistance between the brushes with them disconnected from the control board. It should be about 5 ohms according to the manual.

Les.
 

Panagioite

New Member
Thank you to both reply’s, firstly, the engine starts, runs, idles and high revs fine, no issue. No voltage reading at two terminals coming out from brushes (brass slip rings) I have cleaned, but no joy. Voltage regulator tests good according to specs, battery is being charged. Tested yesterday both wires running grim idle control to motherboard and no readings. Some research indicates Stator? The machine was being used daily no issues, then lost power all of a sudden.
 

rjenkinsgb

Well-Known Member
Most Helpful Member
No voltage reading at two terminals coming out from brushes (brass slip rings)
The brushes are the energising feed to the rotor, initially powered from the battery; there should be some voltage there.

See the schematics on the last two pages of the service manual Les Jones linked to a couple of posts above -

Look at the top right section: From the battery switch through what looks like a PTC fuse, then two resistors and a diode to field +

The negative field connection goes to 0V (battery -) via a resistor and I believe also by the transistors just below and left; D3 connects straight across the field, though the drawing is missing the lower link.

Do you get a voltage reading between field + and battery - when the battery switch is on?
If not, it's one of the components in the chain to the positive terminal or D3 has shorted out.
(Or the rotor coil has shorted).

I'm guessing it's either the battery switch or a fault on the electronics board is causing the PTC fuse to trip every time it is turned on.
 

Les Jones

Well-Known Member
Most Helpful Member
What is the voltage reading with respect to frame ground on the brush terminals ? Also measure the voltage with respect to frame ground at J1-9 , J1-5 and J1-11 on the control board and report the readings. do these tests with S3 in either of the two idle positions. I don't think the engine needs to actually be running for these tests to be valid. I am very impressed with the service manual as it makes it very easy to understand how it works. I did not expect to find any useful service information when I searched the web.

Les.
 

Panagioite

New Member
Thank you for both of your (quick) replies, it is 8:50 pm here in Papua New Guinea so I will run some tests tomorrow morning and come back to this with some results for the testing. Again, I want to thank you for your reply and the timelines.
Peter
 

shortbus=

Well-Known Member
Most Helpful Member
Thank you to both reply’s, firstly, the engine starts, runs, idles and high revs fine, no issue.
This may be a dumb idea, but are you sure the motor is driving the welder rotor? I mean, is the rotor turning? Maybe as simple as the flex coupling is broken between motor and welder.
 

Les Jones

Well-Known Member
Most Helpful Member
Funny that you say that SB, I thought of that possibility but discounted it after looking at the picture of the unit in the manual, It looks like the alternator is mounted directly on the end of the crankshaft of the engine. (But there still could be a coupling of some sort.) The fact that in post #4 it is reported that there is no voltage reading at the brushes to the rotor goes away from the coupling theory as it should have some voltage across it from the 12 volt battery. Once the alternator is working the excitation winding provides a higher voltage to power the rotor (Field.)
Peter, Thanks for giving your location as it helps to know what time zone you are in.

Les.
 

Panagioite

New Member
Hi all, I have some info and pics if I can post them in here. But firstly, the eng shaft is turning the Stator shaft so yes it’s all engaged. There is (14*) v at the batt and also at the voltage regulator. At the two terminals which connect to the brushes there is (12.41) V when testing the wire terminals, (meaning, they are not connected to the terminals) this is with eng running high rev. On low / or idle (7.31) V and with the wires connected to the brushes terminals and engine running at high rev’s the output is (2.58) V.
I have tested individual wires running to and from the PC motherboard for continuity and all wires test positive (good) continuous/ no burn outs no breaks etc...
On the welding coils / top connectors (positive and negative connections I am getting (10.14) V on high rev, and (5.09) V at Eng. idle.
I ran out of time to do further tests.F0792C7E-AE2C-42AE-BAA3-A05A2AFADEE8.jpegB3DD66FB-6408-4ECB-A6EC-D95F42C848B1.jpegFE872A75-052F-46BD-90FC-52ED6F8508E2.jpegAm trying to load other pics but server is too slow.
 

Les Jones

Well-Known Member
Most Helpful Member
So we now know that the fault is on the negative side of the feed to the rotor. If you can locate the field current feedback resistor can you measure the voltage on both ends of it with respect to the frame ground. Do these tests with S3 in either of the two idle positions. I don't think the engine needs to actually be running for these tests to be valid. This will be a 0.1 ohm resistor with a 5 watt power rating. I can't read the control board schematic to give you the component designation as it just pixelates when you try to zoom in. If you can't find it post pictures of the components side and etch side of the control board and one of us may be able to locate it from the pictures.

Les.
 

Panagioite

New Member
I can’t seem to upload other pics so I will just spell it out. The two wires (+ & -) that attach to the brushes terminals, when testing the wires (disconnected) from the brushes / terminals and eng on high rev’s I get a reading of (12.41) V) when I connect the wires to terminals, and engine running on high revs, testing brushes for voltage I get (2.48) voltage DC.
The test on the welding coil connections (too) pos &neg with eng on high revs I get a reading of (10.14) DCV.
All wires running to the PC/ mother board are continuous no breaks, burns, etc...
I have not disturbed any (internal) parts yet.
 

Panagioite

New Member
I can’t seem to upload other pics so I will just spell it out. The two wires (+ & -) that attach to the brushes terminals, when testing the wires (disconnected) from the brushes / terminals and eng on high rev’s I get a reading of (12.41) V) when I connect the wires to terminals, and engine running on high revs, testing brushes for voltage I get (2.48) voltage DC /
 

Les Jones

Well-Known Member
Most Helpful Member
While reading back though the posts to try to make sense of the readings from posts #13 and #14 I realised that I had not read all of post #10 I had read up to where you say "At the two terminals which connect to the brushes there is (12.41) V " Then going back to post #6 I had not made it clear enough that the reading I requested was with the brushes connected as normal. I am not clear about the readings in posts #13 and #14 if those readings are between the terminals or the voltage with respect to frame ground at one or both of these terminals. As you now seem to have indicated that the brush terminals are marked + and - in future can you give the readings in the form ground to + terminal and ground to - terminal or voltage between the terminals. I m not clear what you men in post #10 when you say "the output is (2.58) V." Can you clarify these readings. If the problem you are having uploading pictues is due to the file size then there is program that I use to reduce the resolution and thus the file size called "Image Resizer for Windows"
This is the URL to download it https://www.bricelam.net/ImageResizer/

Les.
 
Last edited:

Panagioite

New Member
G’day all,
Didn’t mean to keep you chaps hanging, power outage and network done, joys of living in PNG.
I am going to try and make this a bit more clear.

1. Brushes / terminals- testing / with(wires disconnected) and
Switch on (S3) low - (+) wire - 0.001;
“. “. (S3) high (+) wire -0.002
“. “. (S3) low (-) wire - 0.002
“. “. (S3) high (-) wire 0.001

Terminal Wires - Testing; with Switch (S3) off:
1. POS- wire - 2.37 vdc
2. Neg - wire - 0.160 vdc
3. Switch (S3) on: Low. High
POS wire - 4.20 3.04
Neg wire- 0.253. 0.173

Brushes Terminal Testing with wires connected:
W/ Switch on- Low. High
1. POS terminal - 0.278. 0.258
2. Neg terminal - 0.280. 0.261

Batt/ Starter switch testing: Switch on;

1. Batt feed wire - 12.92 vdc same as batt
2. 1st red wire to switch - for idle - (12.92) low
(1.30) high
3. 2nd red wire - for high revs - (12.92) low
(12.92) high

Coming to the P.C. Board / two wires running out from PC to windings # 6 &7 (0) reading

PCBoard - ID numbers: L12198-1C1
Potted - 7032869

I am working on the conversion of the pics. If it is the mother board (P.C.) any idea where I can g t one?
Cheers,
Peter
 

Les Jones

Well-Known Member
Most Helpful Member
This is the only relative information to tracing the fault at the moment.
Brushes Terminal Testing with wires connected:
W/ Switch on- Low. High
1. POS terminal - 0.278. 0.258
2. Neg terminal - 0.280. 0.261
This now points to the fault being in the positive feed to the brushes for the field. (Not the negative side as I thought when I only read as far as where you gave the voltage at the brush terminals. I had assumed that this was at the brush terminals with the wires connected to them.)
Measure the voltage with respect to frame ground at J1-9 , J1-5 and J1-11 on the control board as requested in post #6. Check that J1 is properly connected and that the connections are not corroded. I suspect the problem is around the 20 ohm resistor on the block diagram of the control board shown in drawings G7,8,9.
It is not quite as simple as a single resistor when looking at the schematic of the control board. It seems to be two 10 ohm resistors in series and a thermistor or thermal fuse. If you get a reading of about 12 -14 volts at J1-9 but only get a low reading at J1-11 then the fault is on the control board and we would need pictures of the control board to direct you to doing tests on the board.
I don't know where you would get a control board other than from the manufacturer. (I have never worked on generator sets other than one I made about 40 years ago using a Fiat 500 engine and a 5KVA alternator.)

Les.
 

EE World Online Articles

Loading

 
Top