GNB 2100LP industrial battery charger

[MartinConnolly]

I have two of these, both showing F06 error 'no output current'. They charge 48v banks of batteries in warehouse reach-trucks. I can find nothing on the net about this other than the manual says 'check the fuse, SCRs and connecting cable. I've checked the fuse and cables.
So, SCRs. What are they? Can anyone help? This is heavy electricals for me. It runs on 3 phase 240v power and looks scary!

[petehall347]

Re: GNB 2100LP industrial battery charger

silicon controlled rectifiers ..thyristors

[sam_sam_sam]

Re: GNB 2100LP industrial battery charger

Unless you have some troubleshooting skills I would suggest that you have some one repaired this charger for you

However if some understanding of electricity and electronics components you could attempt to fix it but you would have to take detail pictures of the board front and back of the board or boards and post them

But you would have to do your research on what a SCR is and what it does it work and what other compounds are on the board and how these components work in the circuit before you could even attempt to try to repair this board issue

[redwire]

Re: GNB 2100LP industrial battery charger

Posting clear pictures of the board would help in figuring out why there is no output current. Cold-solder joints I find are a problem on high power equipment.
It might not be the SCR's at all, don't fear them lol

[CapLeaker]

Re: GNB 2100LP industrial battery charger

[MartinConnolly]

Re: GNB 2100LP industrial battery charger

Here are photos of the the insides, plus the circuit diagram stuck to the inside of the cabinet. You can see the 3-phase lives come in to a circuit breaker, then each go to their own huge transformer. The output from these goes into this strange metal contraption at the top. Coming out of this is the 48v DC positive and negative. The positive goes through a fuse, the negative through a strip of metal. What is this? It is marked '150A 60mV'. Finally, the negative cable going out is melted through. The positive looks scorched too.
Can I just replace the melted cable? Why did it melt? It's 20 years old and so are the batteries it charges. Could age be an issue?

[redwire]

Re: GNB 2100LP industrial battery charger

I see the wire melted and badly overheated, sometimes this is a factory poor connection that just ran hot for years and finally cooked, or there was an overload - but there is a fuse on the (+) output so I don't think you can really do high current damage here without blowing the fuse.
The copper-looking block is a current-shunt resistor that would drop 50mV at 150A, it is used to meter the charging current.

I would replace the cable and it is customary to re-torque all the high current lugs as they do loosen up with age.
Look for any other short-circuits but I can't see one that would cook that wire specifically.
Wild guess is a defective factory cut/crimp on that lug made it run hot and eventually degrade and burn up.

[redwire]

Re: GNB 2100LP industrial battery charger

Also I noticed in a spot they used the wrong sized lug for the bolt size. The shunt right side you can see the lug hole is huge compared to the bolt - so it makes a crappy connection with all that air gap. This charger seems to be in the 100-150A league, that's a lot.

[CapLeaker]

Re: GNB 2100LP industrial battery charger

Also I noticed in a spot they used the wrong sized lug for the bolt size. The shunt right side you can see the lug hole is huge compared to the bolt - so it makes a crappy connection with all that air gap. This charger seems to be in the 100-150A league, that's a lot.

Redwire, nothing escapes your eye! Very good catch! Seems like the charger had problems there before.
Not sure what to think, but it seems there must be more to this charger than we see on the pic.

[eccerr0r]

Re: GNB 2100LP industrial battery charger

Where are the phantom SCRs?

[redwire]

Re: GNB 2100LP industrial battery charger

The power semiconductors appear to be mounted on the aluminum plates for small heatsinks. It should have a cooling fan? I think it has just six rectifier diodes? No SCR's in the schematic. The control board just seems to open the main contactor when charging is finished. It would be a bit hard on batteries with no regulation or equalize charge etc.

Sometimes in manufacturing you run out of the part (lug) and make do using some similar part (lug with bigger hole) while the boss yells at you just to get the things built and out the door.

[MartinConnolly]

Re: GNB 2100LP industrial battery charger

Please ignore the previous pictures. They were of much older chargers which we are going to scrap. Anyway, this is the insides of the charger in question. It's much more modern and I can't see any fault with it.
Here's what I know...... The three phase power comes into an RFI board you can just see at the bottom right, under the visible board. The three lives come out at the top, black wires, and go into a three phase bridge rectifier. There's then some MOVs, a smoothing cap etc to provide DC. On the side of the heat sink running top to bottom in the middle, not visible in this picture, are 8 power transistors which I guess provide the 48V DC, which is then transferred to the board on the left. I don't know much about this, other than it is marked '7kW output board' so some serious power here. I can't fathom what this does.

Can anyone help me here please.

[MartinConnolly]

Re: GNB 2100LP industrial battery charger

PS. Sorry the picture is rotated 90 degs anticlockwise. Turn it clockwise and it makes sense.