What happens if larger motors are connected to the PDB?
For example 8x30 Ampere = 240 Ampere
I am wondering if it makes sense to use or to go better with the normal baseboard and plug the batteries directly in the ESCs.
Which PDB?
You’ve tagged CUAV but more info would be better.
APD make high current PDBs too.
CUAV sells a Can PDB base board with indicating 110amps max continue current and 180amps max for their cores.
What happen if the ESCs demand 300amp and the battery can support?
Does the board shut down or burn down?
Yes, you should consider the max continuous current for safe design.
I am recommending you use PDB which can handle at least 240A.
Also check below post might be helpful:
Large Power Distribution Board (TL2996) - Hardware / Multirotors - ArduPilot Discourse
Many thanks for the reply and thanks for your post. However I am looking for a PDB with 500 amps and minimum 8 channels for ESCs.
Therefore we are interested in the logic behind the CUAV Can PDB as it can balance 8 outputs.
We would like to know if it shuts down if the power demand is over the max. Amps of the PDB or if it simply limit the current to let the PDB run stable?
It will depend somewhat on whether the CUAV CAN PDB uses a hall effect current sensor or resistor.
The hall sensors can often handle more current flow than they can measure.
APD have a 360A and 500A PDB but they dont include a current sensor, you could add a Mauch current sensor.
I’m not associated with APD at all - it’s just what I would use for that amount of current - I know they can handle it with ease.
Any thanks for the APD link, however I would like to have a feedback from CAUV as I have one of the Can PDB boards from them and I do not want to find it out by trail and error.
Seems to be that the APD is good choice. It would be interesting what each algorithm of APD and CAUV does to understand what happens at different failure cases:
Engine short circuit
ESC short circuit
Battery shortrcircut
Battery overpower and ESC over power demand
Would be really great if one of the companies would state that in their documentation. This would make failure cases more predictable.
As I mentioned the APD PDB does not have a current sensor unfortunately. I do know they’ve been independently tested beyond advertised ratings successfully. The people testing got bored when nothing was going wrong after hours and packed up and went home - so these are not cheap barely-capable low end hobby grade items.
I believe the APD PDBs would handle double their rated current for a few minutes, based on what I know of the testing.
I do not doubt the product quality but the behavior in professional environment must be clear for each component other wise it is easy, you cannot use the component if you do not exactly know what happens in each failure case.
Typically PDBs do not power down. They simply burn up in a ball of fire 
.
Especially at 500A.
Contact APD directly. I’m pretty sure they can explain the published specs. APD is used in commercial and industrial designs, plus they can build you something custom if you need.
As much as I like some CUAV gear, I’ve pointed out a simple error in one of their designs a couple of years ago and its still not changed nor did they acknowledge the issue. So see what sort of details you can get on their can PDB.
I’ll actually be interested to find out too.
Would be spectacular, but we can’t afford that:)
Explain the spec will not be enough. Explain hte behavior beyond the limits.
The spec is also not a real spec oor do you know what your PDB does if 2 ports demand 300 Amp and the other 2 250amps?
How the algorithm work and decide…
The PDBs don’t have any algorithm, it is plain old conductivity or resistance.
It will be the ESCs that “decide” on what to do in an over current or low voltage situation - limit, shut down, catch fire…
The PDB could also burn if it is low quality for the job.
I know for a fact the APD products are rated very conservatively, so if they say they can do 500 amps then they can do it all day every day. Surges or faults wouldn’t be trivial like +10%, but more like +100%
Did you check their specs online? I’m pretty sure they could give you more detail too.
How good is your ESC that is demanding 300 amps? Or even 150…
What brand is that and the specs?
Please don’t take me as just be argumentative for the sake of it.
This is an interesting discussion to me.
Happy to hear more opinions and data.
We are all aware that not all data gets shared publicly too. Some companies publish conservative or realistic specs, and some can be very borderline or worse.
There’s plenty of products that we can tell have no margin for error.
We are using TMotor Flame and Alpha. But for not such professional use hobby wing platinum up to 150amps is good.
For the models I built I am I tested to the facts. When I got information or when I have tested I can share.
Got facts for those ESCs ? 
Like how much over current they handle and for how long?
Looking at those CUAV power distribution boards, when they talk of “algorithm” it’s only about measuring voltage and current, it’s NOT about how power is distributed to each individual output to ESCs.
PDB’s just dont do that, that is the job of the ESCs.
I think you would need a PDB in excess of what the CUAV models would handle.
Hi Shawn - I’m looking for a replacement for my OEM PDB. Have you used the APD PDB500?