SSTC tripping circuit breaker

[Simranjit]

Hi, my sstc keeps tripping circuit breaker. What am I doing wrong. It runs fine on my 30v power supply. My coil resonates at 80kHz. Waveform looks very good on drain of mosfet with 30v power supply. Here are the things I have tried:
1) Use only single diode to rectify mains ac
2) Use full bridge rectifier with some inductors and capacitor bank 1000uf
3) Use only full bridge rectifier.
4) Use 10ohm resistor in series with primary to limit inrush current.
5) Run logic circuit first and then turn on main switch (vice versa)
No matter what I try. As soon as turn on the switch the circuit breaker pops.  My circuit is more or less the same of what I attached.

[NyaaX_X]

Hello,

Where do you place the breaker.
And, what about the specification of your breaker.

Also, if possible, please show your Vgs of MOSFETs?

[Simranjit]

Hi, the circuit breaker is the grey one. I have also attached gate to source waveform (signal is clamped with two 18v zeners). Mosfet is IRF840.

[NyaaX_X]

Sorry for I still cannot find out which is wrong..

You said that your circuit is more or less the same to the attached.
Could you make a schematic of yours? Or a clearly setting photo of your circuit?
When under 30V, how much power do it take?

And how much turns is your primary? Are there any pulse output / arc before breaker poped?
Just guessing... I have no idea if the impedance of your primary is too low for 80kHz, or if the 1u parallel 1u capacitors could make that near DRSSTC.

[klugesmith]

Is it your goal to switch from "30V DC supply" to rectified mains power?
The posted schematic doesn't show the power switch you speak of, and it has a signal named "120V" on both sides of bridge rectifier.
We could help better if you show a schematic that includes power switch and all three wires from AC power plug.
And be specific about all connections to a node called "PGnd".  Electrically it's just as "hot" as the positive rail on your MOSFET half bridge. You can't connect it to wallplug (grounded conductor or grounding conductor) or to a ground rod.

A variac would be useful for troubleshooting. 

[edit] Can you try a different circuit in your house, that doesn't have a fancy breaker?  Some new breakers are supposed to protect against ground faults _and_ arc faults.   Ground fault will trip if the hot wire and neutral wire currents don't match, in other words if more than 5 mA finds a different route to ground.   I don't know how arc fault sensing works, but guess that SSTC might give it trouble.   Hey, what happens if you switch on your mains rectifier while the half bridge is disabled or disconnected?

[Michelle_]

Just a guess your 30V power supply assuming it's AC is isolated and your mains power isn't, you probably have a neutral hooked up to ground, or some confusion of common, neutral, and ground; if it blows right away as soon as you connect the switch.

[Simranjit]

Hi, I have attached the schematic since it's not final I just drew it with hand. I hope it's ok.
1) Power draw is under 100ma at 30v (12 primary turns) and 300ma @ 30v (6 primary turns) with bench top power supply.
2) No arc before breaker pops when connected to mains.
3) Yes, my goal is to switch to 120v mains
4) I have not tried any other circuit breaker (will try shortly tho)
5) If just connect mains rectifier and capacitor bank the capacitor bank charges up just fine. As soon as apply logic control. The breaker pops.
6) Live (black wire) and neutral (white wire) connected to rectifier. Ground (green wire) is unconnected. Tested it with multimeter.

Edit: Secondary is roughly 994.9 ohms with 34 awg wire on 153.5 diameter which comes out to be 2400 turns

Edit 2: I switched to another circuit breaker and installed a 3A fuse on live wire. It started blowing fuses instead of popping breaker (so I guess that's a win too).

Edit 3: I made a scraiac  . It works fine on mains ac with it although sparks are very small. I'm trying to make it compact  as possible. I would appreciate any suggestions because using variac will make it very bulky. I have a leading edge triac also. Will let you know if that does it any good.

Edit 4: I attached a triac > scariac > mains rectifier. I worked fine and I was able to hear the arc sound change with turning of triac potentiometer until I maxed out the triac potentiometer which tripped the GFIC button on outlet (not the main circuit breaker).

[NyaaX_X]

Make sure your circuit is working fine without anything over heating or not working normally. And under 30V the secondary have some output (it seems the feedback network is working)

Then before new breaker I think you could try to move your circuit far away from AFCI breaker, and make better grounding to absorb some of EMI.
Or if there are some rooms are not under the AFCI breaker (sorry I do not familiar with power distribution)?