Using the 24v from the PSU

Bambu Lab P1 Series User Mods
1

Hi all,

Have a bento box with 24v fans with a simple switch so I can turn it on when needed.

I’ve tried wiring it to the PSU but the printer will only turn on when it’s also turned on. Defeats the purpose of a switch for the bento as it has to be on for the printer to turn on.

Is this the way the PSU works?
Any way around this?

Thanks, Josh

2

Are you saying the printer only turns on when you also turn your newly added fans on? If so, your “simple” switch is not wired correctly. Show us your wiring diagram.

3

Yes. If the fan switch is off, the main switch at the back won’t turn on the printer. They both have to be on for it to turn on.

All positives (fan and PSU) are wired to one pole of the switch and the negatives to the other. It’s a SPST switch linked below.

I’m not the only one to have this issue but it seems some do and some don’t The Reddit link is someone else with the same issue. Not sure if it’s a P1 v X1 issue or perhaps newer versions? Something to do with CANBUS?

Thanks, Josh

https://www.jaycar.com.au/spst-mini-rocker-switch/p/SK0984?pos=17&queryId=2c120d7924f9c574d7469b2f7ab36ea3&sort=relevance&searchText=spst%20switch

https://www.reddit.com/r/BambuLab/comments/118jvdz/comment/lelgoxr/?context=3

4

You wired a 24V fan directly to the main switch? Is there 24V on that switch as opposed to 120VAC or higher depending on your country?

Your explanation is not clear enough for me to comment any further unless you show us a wiring diagram of what you’ve done.

1 Like
5

Okay, thanks for asking for the wiring diagram! Started drawing it out and then realised I made a dumb mistake and was shorting it…

I’ll rewire it and hopefully it’ll all be good.

Thanks

1 Like
6

It’s a good habit to always sketch up electrical circuits first. Some mistakes can be expensive if not caught early.

2 Likes
7

Yeah I do for more complex stuff, was just thinking simple switch but here we are…

1 Like