On several occasions I had a long print job mysteriously stop after 20 - 30 minutes. The problem is the Velleman 100 Watt power supply which has a thermal cutout. It is underrated, and overheats when running with the heat bed turned on. Without the heat bed, the 100 Watt supply can handle the load. The reprap wiki electronics forum recommends an 8 amp supply when running the print bed of the same 15 volt supply as the extruder. The Velleman supply is marginal at 6.6 amps. It is not an intermittent failure - the supply is simply not able to handle the load.
I returned the supply to Velleman, but bought a 150 Watt (10 amp) supply to replace it. I have no problems with the new supply overheating on long print jobs.
The new supply has superior convection cooling, and costs less than a new Vellerman supply. It does not get hot to the touch as does the Velleman supply. It is open frame with convection cooling, unlike the totally enclosed Velleman supply. See the following on ebay:
When (if) Velleman sends me a new supply, I plan to sell it on ebay with a warning that it is not adequate for a K8200 printer if the print bed is used.
Once again.
The power supply is not under rated.
The one shipped with your printer may have been faulty, It happens.
I have been running mine for well over a year with out a problem.
Yes with the bed on and a few prints for over 12 hours.
The one shipped with your printer may have been faulty, It happens.
I have returned the power supply to Velleman under a warranty RMA. I hope they test it under load or they will not see the problem.
Nevertheless, the supply ran so hot that I was afraid to use it. If they repair or replace it, I will retest it to see if it still runs at a very high temperature.
[quote=“Wrong Way”]Once again.
The power supply is not under rated.
The one shipped with your printer may have been faulty, It happens.
I have been running mine for well over a year with out a problem.
Yes with the bed on and a few prints for over 12 hours.[/quote]
Not really under rated but not very far from that though
Just add up the drawn currents of extruder and bed and you closely reach the 100W of the original power supply ratng.
If you want to print ABS or alike you still have to upgrade the heatbed to an additional (24V) supply.
That case the Velleman supply will easily power the rest.
Sorry to read that.
Make sure room temp. does not exceed 30°C and make sure power supply is not covered during printing.
We assume that your printer was not modified in any way so that power consumption would increase (e.g. other bed, heaters or fans)?
Anyway, we’d recommend to return it for inspection/exchange to your distributor or direct to Velleman.
My power supply had a thermal cutout. It got very hot, but would shut down to protect itself. The blue light would go out, them come on again, but the print job was interrupted. It sounds as though the thermal cutout in your supply did not work.
I bought a 15 volt 150 watt power supply (new not used) on ebay for about $34 USD. To be safe I added a ferrite core inductor to the DC output, as the original power supply has. These ferrite core RF filters are used by ham radio operators, are very common, and are available at common stores such as Radio Shack in the US. I paid only $2.99 for a package of two ferrite cores.
A possible mod is to use a 24 volt power supply for the heated bed. In that case the original 15 volt supply handles the rest. The only problem is that the “heater 2” MOSFET cannot drive the 24 volt bed directly. A relay or other electronics is required to switch the 24 volts. The reason people do this is because the bed will reach 50 degree Celsius much faster.
Using 15 volts my extruder reaches 190 degrees C in about three minutes. Using 15volts my bed takes about 9 minutes to reach 50 degrees C.
The fets are low side switches, so feeding the heaters from 24v works just fine. You can do this be removing one wire from the 4 way heater plug, or there is a convenient place to cut a track on the PCB and use the terminal block for the heaters and the co-axial connector for the rest (on my board I’ve replaced that with another terminal block.
