terminal got burnt April 23, 2015 10:13PM |
Registered: 10 years ago Posts: 476 |
Re: terminal got burnt April 24, 2015 02:47AM |
Registered: 9 years ago Posts: 30 |
Quote
sarf2k4
Hi, I wanted to ask you guys about this problem, I got my terminal connection burnt last night after about 4 stressful print in total of about 15 hours I think. Last night when I tried to heat the bed, it suddenly turned off when it reaches 70'c. I believe I am using a 10awg wire; quite sturdy wire with a diameter of around 2.5mm (copper).
The board has little solder plate left (place to connect the joints using solder irons), and I am planning to solder the wire directly to the board tomorrow with the help of my friend, I am not sure if it is still usable to solder the wire on to it. I am running on 12v system and I believe the mosfet/terminal unable to handle 15a current. But mine was different from this guy here while referring to this site makes me confused with the terms in the table
I got few questions:
- Does household cable (neutral,live,earth, the one with blue, brown, yellow stripe green) can be used for 15-20a current?
- Is there a reference to a wire gauge and their rated current specifications?
- Was it my wrong cable selection of this 10awg, a hard cable that has memory effect when bent?
- Will the board still usable?
Regards
-Sarf
Re: terminal got burnt April 24, 2015 03:06AM |
Registered: 10 years ago Posts: 476 |
I will post a picture about the cable I used, it is a multi-stranded cable with about 7 strands and not too flexible. I believe I already clipped that burnt tip apart down to the bin.Quote
csambrook
Quote
sarf2k4
Hi, I wanted to ask you guys about this problem, I got my terminal connection burnt last night after about 4 stressful print in total of about 15 hours I think. Last night when I tried to heat the bed, it suddenly turned off when it reaches 70'c. I believe I am using a 10awg wire; quite sturdy wire with a diameter of around 2.5mm (copper).
The board has little solder plate left (place to connect the joints using solder irons), and I am planning to solder the wire directly to the board tomorrow with the help of my friend, I am not sure if it is still usable to solder the wire on to it. I am running on 12v system and I believe the mosfet/terminal unable to handle 15a current. But mine was different from this guy here while referring to this site makes me confused with the terms in the table
I got few questions:
- Does household cable (neutral,live,earth, the one with blue, brown, yellow stripe green) can be used for 15-20a current?
- Is there a reference to a wire gauge and their rated current specifications?
- Was it my wrong cable selection of this 10awg, a hard cable that has memory effect when bent?
- Will the board still usable?
Regards
-Sarf
That doesn't look to me like a problem with your choice of wire size but rather with the connection of the wire to the board or possibly with the type of wire. Assuming you used multi stranded flexible wire "flex", either the soldering of the connector to the board was poor and offered a high resistance (google "dry joint") or the connection of the wire into the connector was high resistance. That could be because you trapped some insulation in there so there was only a very small contact area of actual copper, or the copper was dirty/tarnished or you didn't do the screws up tightly.
On the other hand your phrase "a hard cable that has memory effect when bent" rings an alarm bell. Assuming your bed moves then you *must* use a multi-stranded flexible cable. If you used a solid cored mains fixed wiring cable then after a while the single cores will start to break and as that happens they will offer a high resistance and get hot at the bend point. It looks to me as if that could be your problem. Perhaps you could post a photo of the wire you used. Even better if you still have the burned bit - that should tell us a lot.
Your board is probably salvagable but it will take some care. I would solder in a new connector then solder a wire from each pin of the connector to wherever it tracks to on the PCB. Also look for how well it is now mechanically supported and possibly give it some more support with glue.
I'm really not trying to be insulting but you might perhaps want to get some soldering practice on a board you don't care about first as you are risking doing more damage as you try to repair it. Try to use a more powerful soldering iron so that the solder melts cleanly and the task can be done quickly. Make sure the solder is properly and fully melted before you try to move the component. Get hold of some flux (a flux pen works well) or as an alternative add some new solder before removing the old (the new solder contains flux). To be fair, power connections are the hardest to solder because of all the copper sucking the heat away.
Good luck with this,
Calvin
Re: terminal got burnt April 24, 2015 04:21AM |
Registered: 9 years ago Posts: 30 |
Quote
sarf2k4
I will post a picture about the cable I used, it is a multi-stranded cable with about 7 strands and not too flexible. I believe I already clipped that burnt tip apart down to the bin.Quote
csambrook
Quote
sarf2k4
Hi, I wanted to ask you guys about this problem, I got my terminal connection burnt last night after about 4 stressful print in total of about 15 hours I think. Last night when I tried to heat the bed, it suddenly turned off when it reaches 70'c. I believe I am using a 10awg wire; quite sturdy wire with a diameter of around 2.5mm (copper).
The board has little solder plate left (place to connect the joints using solder irons), and I am planning to solder the wire directly to the board tomorrow with the help of my friend, I am not sure if it is still usable to solder the wire on to it. I am running on 12v system and I believe the mosfet/terminal unable to handle 15a current. But mine was different from this guy here while referring to this site makes me confused with the terms in the table
I got few questions:
- Does household cable (neutral,live,earth, the one with blue, brown, yellow stripe green) can be used for 15-20a current?
- Is there a reference to a wire gauge and their rated current specifications?
- Was it my wrong cable selection of this 10awg, a hard cable that has memory effect when bent?
- Will the board still usable?
Regards
-Sarf
That doesn't look to me like a problem with your choice of wire size but rather with the connection of the wire to the board or possibly with the type of wire. Assuming you used multi stranded flexible wire "flex", either the soldering of the connector to the board was poor and offered a high resistance (google "dry joint") or the connection of the wire into the connector was high resistance. That could be because you trapped some insulation in there so there was only a very small contact area of actual copper, or the copper was dirty/tarnished or you didn't do the screws up tightly.
On the other hand your phrase "a hard cable that has memory effect when bent" rings an alarm bell. Assuming your bed moves then you *must* use a multi-stranded flexible cable. If you used a solid cored mains fixed wiring cable then after a while the single cores will start to break and as that happens they will offer a high resistance and get hot at the bend point. It looks to me as if that could be your problem. Perhaps you could post a photo of the wire you used. Even better if you still have the burned bit - that should tell us a lot.
Your board is probably salvagable but it will take some care. I would solder in a new connector then solder a wire from each pin of the connector to wherever it tracks to on the PCB. Also look for how well it is now mechanically supported and possibly give it some more support with glue.
I'm really not trying to be insulting but you might perhaps want to get some soldering practice on a board you don't care about first as you are risking doing more damage as you try to repair it. Try to use a more powerful soldering iron so that the solder melts cleanly and the task can be done quickly. Make sure the solder is properly and fully melted before you try to move the component. Get hold of some flux (a flux pen works well) or as an alternative add some new solder before removing the old (the new solder contains flux). To be fair, power connections are the hardest to solder because of all the copper sucking the heat away.
Good luck with this,
Calvin
I do admit I'm pretty bad at soldering as I have started soldering a bit recently for about a month ago, the joint was well last night, it was the wire that snapped, not on the soldered joints.
I bought this wire I thought it would be perfect and able to support 20a current rather than the household appliance cable (I thought just 13-15a) current, then I crimped it to a fork terminal (that looked like wishbone) because the cable perfectly fit to that wishbone terminal
So, uhm, does the home appliance cable can be used?
Regards
-Sarf
Re: terminal got burnt April 24, 2015 04:25AM |
Registered: 10 years ago Posts: 977 |
Re: terminal got burnt April 24, 2015 04:37AM |
Registered: 10 years ago Posts: 476 |
Quote
csambrook
Quote
sarf2k4
I will post a picture about the cable I used, it is a multi-stranded cable with about 7 strands and not too flexible. I believe I already clipped that burnt tip apart down to the bin.Quote
csambrook
Quote
sarf2k4
Hi, I wanted to ask you guys about this problem, I got my terminal connection burnt last night after about 4 stressful print in total of about 15 hours I think. Last night when I tried to heat the bed, it suddenly turned off when it reaches 70'c. I believe I am using a 10awg wire; quite sturdy wire with a diameter of around 2.5mm (copper).
The board has little solder plate left (place to connect the joints using solder irons), and I am planning to solder the wire directly to the board tomorrow with the help of my friend, I am not sure if it is still usable to solder the wire on to it. I am running on 12v system and I believe the mosfet/terminal unable to handle 15a current. But mine was different from this guy here while referring to this site makes me confused with the terms in the table
I got few questions:
- Does household cable (neutral,live,earth, the one with blue, brown, yellow stripe green) can be used for 15-20a current?
- Is there a reference to a wire gauge and their rated current specifications?
- Was it my wrong cable selection of this 10awg, a hard cable that has memory effect when bent?
- Will the board still usable?
Regards
-Sarf
That doesn't look to me like a problem with your choice of wire size but rather with the connection of the wire to the board or possibly with the type of wire. Assuming you used multi stranded flexible wire "flex", either the soldering of the connector to the board was poor and offered a high resistance (google "dry joint") or the connection of the wire into the connector was high resistance. That could be because you trapped some insulation in there so there was only a very small contact area of actual copper, or the copper was dirty/tarnished or you didn't do the screws up tightly.
On the other hand your phrase "a hard cable that has memory effect when bent" rings an alarm bell. Assuming your bed moves then you *must* use a multi-stranded flexible cable. If you used a solid cored mains fixed wiring cable then after a while the single cores will start to break and as that happens they will offer a high resistance and get hot at the bend point. It looks to me as if that could be your problem. Perhaps you could post a photo of the wire you used. Even better if you still have the burned bit - that should tell us a lot.
Your board is probably salvagable but it will take some care. I would solder in a new connector then solder a wire from each pin of the connector to wherever it tracks to on the PCB. Also look for how well it is now mechanically supported and possibly give it some more support with glue.
I'm really not trying to be insulting but you might perhaps want to get some soldering practice on a board you don't care about first as you are risking doing more damage as you try to repair it. Try to use a more powerful soldering iron so that the solder melts cleanly and the task can be done quickly. Make sure the solder is properly and fully melted before you try to move the component. Get hold of some flux (a flux pen works well) or as an alternative add some new solder before removing the old (the new solder contains flux). To be fair, power connections are the hardest to solder because of all the copper sucking the heat away.
Good luck with this,
Calvin
I do admit I'm pretty bad at soldering as I have started soldering a bit recently for about a month ago, the joint was well last night, it was the wire that snapped, not on the soldered joints.
I bought this wire I thought it would be perfect and able to support 20a current rather than the household appliance cable (I thought just 13-15a) current, then I crimped it to a fork terminal (that looked like wishbone) because the cable perfectly fit to that wishbone terminal
So, uhm, does the home appliance cable can be used?
Regards
-Sarf
I look forward to pictures of the cable. Too stiff a cable can be an issue but from your description I wonder if the crimp joint may have been the problem. Clearly the overheating was quite localised and near the connector or inside it. Crimp joints can be deceptively hard to make properly without specialist tools and for this application you are asking quite a lot of the joint, 20A is not trivial. The cheap crimp tools you can get in DIY shops are fairly rubbish and simply crush the connector onto the wire which can result in a joint with quite a small contact area, worse it is difficult to inspect to be sure it's good. Proper crimp tools (expensive) control the shape of the crimp to ensure good contact area which is vital at high currents. Personally, for this application, if I was using a cheap crimp tool I'd be tempted to also run some solder into the joint as well.
I'm not sure if home appliance flex could be used - I've not thought about it very much. My guess is that it would be absolutely fine and to be honest if I was doing this at home for myself I'd probably get hold of some "extra flexible" 13A mains cable, sometimes called "arctic cable". Although it's called "13A" it's actually capable of much more, the circuit is fused at 13A for safety. Current ratings for cable are a little odd anyway, they're a bit of a shorthand, it's really a calculation involving how much temperature rise you can tolerate, how much voltage drop, and how long a cable run.
Re: terminal got burnt April 24, 2015 12:25PM |
Registered: 9 years ago Posts: 30 |
Quote
sarf2k4
Quote
csambrook
Quote
sarf2k4
I will post a picture about the cable I used, it is a multi-stranded cable with about 7 strands and not too flexible. I believe I already clipped that burnt tip apart down to the bin.Quote
csambrook
Quote
sarf2k4
Hi, I wanted to ask you guys about this problem, I got my terminal connection burnt last night after about 4 stressful print in total of about 15 hours I think. Last night when I tried to heat the bed, it suddenly turned off when it reaches 70'c. I believe I am using a 10awg wire; quite sturdy wire with a diameter of around 2.5mm (copper).
The board has little solder plate left (place to connect the joints using solder irons), and I am planning to solder the wire directly to the board tomorrow with the help of my friend, I am not sure if it is still usable to solder the wire on to it. I am running on 12v system and I believe the mosfet/terminal unable to handle 15a current. But mine was different from this guy here while referring to this site makes me confused with the terms in the table
I got few questions:
- Does household cable (neutral,live,earth, the one with blue, brown, yellow stripe green) can be used for 15-20a current?
- Is there a reference to a wire gauge and their rated current specifications?
- Was it my wrong cable selection of this 10awg, a hard cable that has memory effect when bent?
- Will the board still usable?
Regards
-Sarf
That doesn't look to me like a problem with your choice of wire size but rather with the connection of the wire to the board or possibly with the type of wire. Assuming you used multi stranded flexible wire "flex", either the soldering of the connector to the board was poor and offered a high resistance (google "dry joint") or the connection of the wire into the connector was high resistance. That could be because you trapped some insulation in there so there was only a very small contact area of actual copper, or the copper was dirty/tarnished or you didn't do the screws up tightly.
On the other hand your phrase "a hard cable that has memory effect when bent" rings an alarm bell. Assuming your bed moves then you *must* use a multi-stranded flexible cable. If you used a solid cored mains fixed wiring cable then after a while the single cores will start to break and as that happens they will offer a high resistance and get hot at the bend point. It looks to me as if that could be your problem. Perhaps you could post a photo of the wire you used. Even better if you still have the burned bit - that should tell us a lot.
Your board is probably salvagable but it will take some care. I would solder in a new connector then solder a wire from each pin of the connector to wherever it tracks to on the PCB. Also look for how well it is now mechanically supported and possibly give it some more support with glue.
I'm really not trying to be insulting but you might perhaps want to get some soldering practice on a board you don't care about first as you are risking doing more damage as you try to repair it. Try to use a more powerful soldering iron so that the solder melts cleanly and the task can be done quickly. Make sure the solder is properly and fully melted before you try to move the component. Get hold of some flux (a flux pen works well) or as an alternative add some new solder before removing the old (the new solder contains flux). To be fair, power connections are the hardest to solder because of all the copper sucking the heat away.
Good luck with this,
Calvin
I do admit I'm pretty bad at soldering as I have started soldering a bit recently for about a month ago, the joint was well last night, it was the wire that snapped, not on the soldered joints.
I bought this wire I thought it would be perfect and able to support 20a current rather than the household appliance cable (I thought just 13-15a) current, then I crimped it to a fork terminal (that looked like wishbone) because the cable perfectly fit to that wishbone terminal
So, uhm, does the home appliance cable can be used?
Regards
-Sarf
I look forward to pictures of the cable. Too stiff a cable can be an issue but from your description I wonder if the crimp joint may have been the problem. Clearly the overheating was quite localised and near the connector or inside it. Crimp joints can be deceptively hard to make properly without specialist tools and for this application you are asking quite a lot of the joint, 20A is not trivial. The cheap crimp tools you can get in DIY shops are fairly rubbish and simply crush the connector onto the wire which can result in a joint with quite a small contact area, worse it is difficult to inspect to be sure it's good. Proper crimp tools (expensive) control the shape of the crimp to ensure good contact area which is vital at high currents. Personally, for this application, if I was using a cheap crimp tool I'd be tempted to also run some solder into the joint as well.
I'm not sure if home appliance flex could be used - I've not thought about it very much. My guess is that it would be absolutely fine and to be honest if I was doing this at home for myself I'd probably get hold of some "extra flexible" 13A mains cable, sometimes called "arctic cable". Although it's called "13A" it's actually capable of much more, the circuit is fused at 13A for safety. Current ratings for cable are a little odd anyway, they're a bit of a shorthand, it's really a calculation involving how much temperature rise you can tolerate, how much voltage drop, and how long a cable run.
I did read somewhere in other threads here too, about the cable would be at least 16awg while the link on my first post to the awg chart states that household cables runs on around 14-12awg. I compared mine with the table based on the diameter of the coppers inside.
The cable should be at a length of 50-100cm for the direct solder on the pcb later, I also remember I do read an info about the terminals where you better off by soldering the cable directly to the pcb long ago. I think I'm going to write my own experience off somewhere else later when I got these problem done, I got too much problems coming one after another on this printer
The hole on the pcb is should be around 1-2mm wide while my cable cannot fit the whole strand when I attempted to run it through the hole.
Apologies with fragmented information in this post
Regards
-Sarf
Re: terminal got burnt April 24, 2015 01:28PM |
Registered: 10 years ago Posts: 476 |
Re: terminal got burnt April 25, 2015 05:21PM |
Registered: 9 years ago Posts: 30 |
Quote
sarf2k4
I am unable to upload pictures of the cable used, i will upload after i bought another cable. I just checked some stores for extension sockets for reference, i found the thickest is 1.25mm2. I am confused by this number and the awg chart references on which i should refer, mm2 or the mm?
The hole in the pcb i think should be around 1mm was it? If i were to use a 1mm copper wire, that would be 17awg i think, and its too thin to carry 15a loads, most likely will end up like another thread in my first post.
Regards
-sarf
Re: terminal got burnt April 25, 2015 10:22PM |
Registered: 9 years ago Posts: 125 |
Re: terminal got burnt April 26, 2015 06:06AM |
Registered: 10 years ago Posts: 476 |
Re: terminal got burnt April 26, 2015 07:40AM |
Registered: 9 years ago Posts: 125 |
Re: terminal got burnt April 26, 2015 08:03AM |
Registered: 10 years ago Posts: 476 |
Quote
itchytweed
My apologies for not including mm3 for the wire. I deal with conversions between both professionally and just plain forgot. Here is a page that has a simple AWG/mm3/amps capacity chart - [www.wecoconnectors.com].
The rule of thumb is that any connection is a point of failure and thermal cycling aggravates that process because of expansion/contraction. I have replaced many a crimp connection and burnt wire because the crimp came loose, not properly compressed, or the wrong sized wire/crimp combination. Whenever I know that a crimp connection is going to be carrying high currents or subject to vibration, I always solder it after crimping. For me, that is an added insurance policy. One of the biggest issues with insulated crimps is transferring the compressive force from the crimp dies to the crimp itself through the insulation. The insulation can itself cause issues as well - moisture affects the material - as it does with our filament when printing. If the insulation soaks up moisture and you crimp it, it squeezes out and does not transfer the force correctly which results in an undercompressed crimp. Another issue is the crimp itself and the metal it is made from. I have had situations where I spent the funds for a batch of crimp connectors from what I thought to be a reputable manufacturer and they ended up to be substandard. So, in my book, it is a lottery and I don't like taking chances as the end result can be really expensive, especially in a production environment.
Because of this issue, I prefer to use uninsulated crimps. After crimping, I solder the connection and then use heat shrink tubing over the barrel part to insulate it. For this, I prefer white over black because I can use a black permanent marker and label what the wire is.
On to the subject of wire. I remember someone on a different thread talking about using teflon insulated wire for the heat bed wiring. My issue with teflon insulation is that it is fragile. Any rubbing against a sharp object, such as a corner, and it pierces very easily and to properly remove the insulation for connections, a thermal stripper has to be used to melt through it. I would suggest, instead of teflon, use a wire that uses a silicone insulation. As a suggestion, here is a wire distributor's webpage for UL 3239 / UL 10475 silicone wiring: [www.awcwire.com]. There is enough information on the page that can be taken and used to acquire the same from a different distributor. The insulation is thicker than regular wire, but it is quite flexible, heat tolerant (to 150 deg C / 300 deg F), and rugged. This would make for good use on the moving heat bed connection.
I think that I have covered enough for now. Have a good day.
Re: terminal got burnt April 26, 2015 10:01AM |
Registered: 9 years ago Posts: 125 |
Re: terminal got burnt April 26, 2015 10:44AM |
Registered: 10 years ago Posts: 476 |
Re: terminal got burnt April 26, 2015 12:52PM |
Registered: 9 years ago Posts: 125 |
Re: terminal got burnt April 26, 2015 08:30PM |
Registered: 10 years ago Posts: 476 |
Quote
itchytweed
Changing the connector to a 30 amp unit will make it more rugged but now the limit becomes what the board construction / traces can handle. Too much current there and the traces will fuse open.
This can help as using the fork style connector with a screw terminal will help with the current carrying.
Re: terminal got burnt April 27, 2015 09:02AM |
Registered: 9 years ago Posts: 125 |
Quote
sarf2k4
Quote
itchytweed
Changing the connector to a 30 amp unit will make it more rugged but now the limit becomes what the board construction / traces can handle. Too much current there and the traces will fuse open.
This can help as using the fork style connector with a screw terminal will help with the current carrying.
Wouldn't that be the same if I solder a higher capacity cables onto it?
Re: terminal got burnt April 27, 2015 09:15PM |
Registered: 10 years ago Posts: 476 |
Re: terminal got burnt April 28, 2015 11:56AM |
Registered: 9 years ago Posts: 125 |
Quote
sarf2k4
Let's say I'm running my bed at 110'c with 270'c extruder, how much amp would that be pulled?
I am using geeetech prusa i3 and the pid thingy should be default values, nothings changed
Re: terminal got burnt April 28, 2015 02:01PM |
Registered: 9 years ago Posts: 30 |
Quote
itchytweed
Quote
sarf2k4
Let's say I'm running my bed at 110'c with 270'c extruder, how much amp would that be pulled?
I am using geeetech prusa i3 and the pid thingy should be default values, nothings changed
Can't answer question. No usable information. Need two out of the three pieces of info listed: voltage, amps, resistance. If I have volts and resistance, amps is a simple calculation.
Re: terminal got burnt April 28, 2015 08:52PM |
Registered: 10 years ago Posts: 476 |
Re: terminal got burnt April 29, 2015 02:39AM |
Registered: 9 years ago Posts: 30 |
Quote
sarf2k4
Thank you for your reply, I probably going to have myself a terminal block just like the power output probably this weekend fitted on to the power input. As I understand right, this kind of terminal block has a high contact points especially paired with flexible multi strand wire right? A solid core weren't good to be used for these as well?
Correct me if I'm wrong
That is quite a hectic process when finding out the max current
Re: terminal got burnt April 29, 2015 05:11AM |
Registered: 10 years ago Posts: 476 |
Re: terminal got burnt May 02, 2015 10:28PM |
Registered: 10 years ago Posts: 476 |
Re: terminal got burnt May 02, 2015 10:50PM |
Registered: 9 years ago Posts: 606 |
Re: terminal got burnt May 02, 2015 11:06PM |
Registered: 10 years ago Posts: 476 |
Re: terminal got burnt May 03, 2015 12:36AM |
Registered: 9 years ago Posts: 606 |
Re: terminal got burnt May 03, 2015 05:23AM |
Registered: 9 years ago Posts: 30 |
Quote
tadawson
I honestly don't understand what pins you are pushing on, but do know that if you have that tenuous a connection, more heating, burning, and board damage is in your very near future. Myself, I would upgrade to screw down strips (same style as the heater outputs) in the appropriate size, or at the very least, replace the entire connector pair - once a contact overheats that bad, it loses it's springiness and will never make good contact again.
Re: terminal got burnt May 03, 2015 05:34AM |
Registered: 10 years ago Posts: 476 |