[remy_martian]

Why are you double posting material?

 

[gregski]

I went after the Safety Box next

 

[gregski]

and here's what lurks inside

after removing the green circuit board

 

[remy_martian]

What are the two contactors that they use (not the resistor relay)? Can you get markings/label shots of them?

What's the precharge resistor value?

thanks

 

[remy_martian]

Good job on the "safety box" teardown video (I have a time machine...)

Those contactors are likely useless for your truck. Only rated at 120A...seem to be put zere by ze Germans to protect zat expensive 350A fuse 😂

Getting an ohm meter on that resistor will tell you how useful it is for precharging your inverter.

I didn't catch the part number of the precharge relay.

 

[gregski]

so yeah I blew it all up to smitherenes and now feel way more comfortable understanding what the he11 is going on inside this black box, and here to share

both the Panasonic "positive" and "negative" contactors appear to be identical Part # AEV140125 M25

 

[gregski]

the BMW 530e Safety Box internal low voltage wire harness

the BMW 530e Safety Box internal high voltage wire harness (orange wires)

this is the OEM current shunt, aka current sensor, it does not appear to be removable from the green logic board

how it looks from underneath

 

[gregski]

so lets take a look at the negative circuit path from the battery Cell Module # 1 main negative lead into and through this black box

sorry the orientation below is upside down (adding to the confusion I'm sure)

 

[gregski]

here I isolate only the components needed to complete the negative "circuit" through this Safety Box

close up of the negative contactor, the stud sticking up is where the current shunt mounts to to bridge that gap over this contactor in the pics above

 

[remy_martian]

Your latest video on solenoids, contactors, and relays is complete nonsense

 

[gregski]

and here is the internal positive circuit

 

[gregski]

a step by step video of the tear down process

 

[gregski]

here is probably the most important circuit in the entire Safety Box the pre-charge circuit, it tickles the capacitor inside the inverter with gentle current before shooting all of it down it's throat, this keeps the capacitor from blowing up

it consists of a relay and a resistor and utilizes the same fuse as the positive contactor in the positive circuit mentioned above

the white bar of soap looking block is a 15 ohm resistor

 

[remy_martian]

The precharge circuit does not utilize the fuse, it is part of it. The actual fuse in the circuit is actually one of the orange wires, the resistor, or the relay, which seems reckless...

The precharge resistor, orange wires, and relay is, however, protected by inference by that circuit board you plan to discard because it simply opens the relay when a fault is detected in the circuit, which includes those capacitors the "safety box" is determined not to blow up....allegedly. Shows how ignorance and strict reliance on Google can set your car or truck ablaze by tossing out a critical circuit element.

The Panasonic relay AEC51012 is, from what I can tell, a 400V 5A relay, which means the precharge resistor must be at least 80 ohms. It's allegedly 15 ohms, which means a peak inrush current of 26 amps into the inverter and through the relay...

 

[remy_martian]

Correction. The Arrow site as indexed is incorrect:

The relay is 10A, which make the min resistor size 40ohms.

Found the datasheet. Contacts are rated for 30 seconds at 30A. Again, the board planned on being thrown out will time the charge/discharge cycles of the precharge to ensure the relay specs are not exceeded, since the 15 ohm relay will peak out at 26A. This is an abuse scenario, not expected operation that may need oversight by the controller.

 

[gregski]

the BGR30TQY high power wire wound glass core ceramic resistor excellent for inrush current is a 30 watt resistor 15Ω J

BGR = wire wound glass core

30 = 30 watts

 

[gregski]

found this little gem hidden inside of one of Damien's videos

 

[remy_martian]

All of Damien's videos are gems. The most underappreciated channel on Youtube, though it's his fault for telling people not to comment and to unsubscribe 😉