Yes, I can disconnect the amps. Do you want me to do that and measure the voltage across the primaries and caps again?
Help me understand what should be happening. Should the voltage across the primaries be closer to 234VAC? Does that mean a lower voltage drop across the 100W bulb and thus less current flowing through the system?
I'm a little confused because in the factory 110V config, there was a 121-44.5=76.5VAC drop across the 40W/220V bulb. Is that current flow acceptable, because it still seems high.
Help me understand what should be happening. Should the voltage across the primaries be closer to 234VAC? Does that mean a lower voltage drop across the 100W bulb and thus less current flowing through the system?
I'm a little confused because in the factory 110V config, there was a 121-44.5=76.5VAC drop across the 40W/220V bulb. Is that current flow acceptable, because it still seems high.
It's six channels of class AB on ~70V. The amplifier is supposed to draw 125W (about 180VA if they didn't mean 125VA by "125W") at idle according to the manual. A 100W bulb is much too small to start that up.
http://www.bkcomp.com/fileadmin/content/content_products/manuals/Past/Amp/AV5000SERIESII.pdf
The problem I have is on how to advise without risking blowing up someone's amplifier if there is a fault.
Adding one amplifier at a time to the PSU and proving each one is OK is the safe but somewhat longwinded approach.
Changing the bulb to a big one could allow the amp to bias up correctly and run, but if there is a fault the big bulb will not limit sufficiently to protect the system.
Even fusing the supplies to each amplifier may be too slow to protect against a wiring fault. The semiconductors blow before the fuses. That's why I have to keep reminding builders that the fuse is there to stop one setting fire to one's home, not to protect the equipment that has already gone faulty.
Adding one amplifier at a time to the PSU and proving each one is OK is the safe but somewhat longwinded approach.
Changing the bulb to a big one could allow the amp to bias up correctly and run, but if there is a fault the big bulb will not limit sufficiently to protect the system.
Even fusing the supplies to each amplifier may be too slow to protect against a wiring fault. The semiconductors blow before the fuses. That's why I have to keep reminding builders that the fuse is there to stop one setting fire to one's home, not to protect the equipment that has already gone faulty.
Why not just use a voltage converter, like this one, to convert the line from 220v to 110v? 1500 watts should be enough.
I'm pretty certain everything is OK. If the primaries had been wired with incorrect phase the effective inductance of the transformer would have been close to zero, so the voltage across the light bulb would be very near full mains voltage, and the secondary voltage would be zero.
There are really only 4 permutations:
parallel = original wiring
parallel with wrong phase = no secondary voltage, full lamp
series = correct wiring
series with wrong phase = no secondary voltage, full lamp
I'd guess the gray wire is one end of a 20V wiring, used for 240V.
There are really only 4 permutations:
parallel = original wiring
parallel with wrong phase = no secondary voltage, full lamp
series = correct wiring
series with wrong phase = no secondary voltage, full lamp
I'd guess the gray wire is one end of a 20V wiring, used for 240V.
AndrewT said:
If the amplifier is made in such a way that the different channels can be disconnected then one could do that. It's a pretty good idea, but wasn't the only change the primary connection of the transformer? If it works in idle and the output voltage is correct the modification should be finished.
Hi Everyone..
If I were doing it I would run a robust 110 circuit and be done with it. 220 is nice but if you ever move to another house or physically take the saw to another location having to have 220 is may just become another problem.
Use a 20 amp breaker and 12 gauge wire with a receptacle rated at 20 amps and you will be flying high and making sawdust.
If you insist on 220 then be smart and use a common dryer plug/receptacle so if you do go somewhere there might be a chance you can plug into a dry circuit to power your saw. Plus I would install a new longer line cord on the saw so you can move it around and still reach the 220 outlet. Again if you ever take the saw to another house/location the longer cord will turn out to be a blessing. 220v extension cords are not readily available.
If I were doing it I would run a robust 110 circuit and be done with it. 220 is nice but if you ever move to another house or physically take the saw to another location having to have 220 is may just become another problem.
Use a 20 amp breaker and 12 gauge wire with a receptacle rated at 20 amps and you will be flying high and making sawdust.
If you insist on 220 then be smart and use a common dryer plug/receptacle so if you do go somewhere there might be a chance you can plug into a dry circuit to power your saw. Plus I would install a new longer line cord on the saw so you can move it around and still reach the 220 outlet. Again if you ever take the saw to another house/location the longer cord will turn out to be a blessing. 220v extension cords are not readily available.
The real problem is the "trip curve" of the breaker is too sensitive for the inrush current duration when two transformers are used - the step up or step down and the internal one in the amp. The breaker trip curve is a rating similar to a that of a fuse time delay like fast acting or slow blow.
Contact a local electrician to see if they can install a breaker with a higher trip curve rating in your panel. Here they are rated with letters like C-curve or D-curve or K-curve with higher letters corresponding to longer delays. You probably have a C which is fast, when you need a D or a K which are rated for motor loads, etc.
If this option isn't possible you could look at an inrush current limiter.
Contact a local electrician to see if they can install a breaker with a higher trip curve rating in your panel. Here they are rated with letters like C-curve or D-curve or K-curve with higher letters corresponding to longer delays. You probably have a C which is fast, when you need a D or a K which are rated for motor loads, etc.
If this option isn't possible you could look at an inrush current limiter.