Ratrig Vcore 3.1 4028 Fan and Duet 3 Mini 5+ - Current Draw

RogerPodacter

@rushmere3d I'm going through the guide now. So far i have a separate 12V 2 Amp buck converter installed pulling 24V from the PSU down to 12V. I have the red/black positive and negative wires of the 4028 fan going directly to the external 12V buck converter.

Next i've setup my layer fan 0 in Gcode as follows, so that i invert the output for PWM, add a tach RPM sensor, and set the frequency to 100 Hz.

M950 F0 C"!out4+^out4.tach" Q100

But i'm a bit confused precisely how to wire this up. the 2 power wires are working obviously provide the fan always on when i power it up since i dont have the tach and PWM wire connected yet. i am wondering do i have to ground the Duet board and the buck converter together, but since they all come from the same Meanwell 24V power source i would think they are already commonly grounded together. Maybe that's a dumb question, i could just check continuity with a multimeter.

RogerPodacter

@rogerpodacter to answer my own question, yes there is continuity so all the power sources are grounded together.

Now my last confusion is connecting the PWM wire and tach. The tacho is easy i guess.

Here is the Duet board output 4 pins and my notes what i am thinking to connect, but i think i'm still confused:

out4- (brown PWM wire from 4028 fan)
out4.tach (yellow sensor wire from 4028 fan)
V_OUTLC1+ (not used, already connected to buck converter)
Ground (not used, already connected to buck converter)

dc42

@rogerpodacter the datasheet for that fan indicates that it draws up to 1.2A, which is very high for that size of fan. It may even be a misprint. If not, then it probably only draws that amount of current when stalled and during startup.

The 12v regulator on the Duet 3 Mini is rated at 1A but in practice the overcurrent doesn't kick in until somewhat higher. So there is a very good chance that the Duet 3 Mini will drive that fan without any problems, unless you stall the fan by jamming it.

If you have a multimeter, you could connect it in series with the fan and measure the current draw under various conditions.

oliof

@dc42 these fans are for high performance data center servers and have an onboard controller that put them at full speed as long as PWM is not set up, i.e. during boot up. Only a short time on a standalone board, but many seconds in an SBC configuration. I've used an external 5A 24v to 12v step down converter usually used in trucks to drive car appliances made for 12v applications, getting power direct from the PSU. I have not measured their power draw.

There are other versions of the 4028 that draw up to 2A, where I wouldn't recommend hoping it will never draw full current.

RogerPodacter

@dc42 Thanks, for now i already have the external 12V hooked up, but good to know in the future i could probably go back to fully pulling from the board.

Update, i have the fan connected and seemingly working correctly. I am getting accurate RPM readings in the Duet web interface up to 25,000 RPMs. The only problem is at 0% the fan still spins at 8000 RPM, which i've read somewhere that this is normal behavior for some PWM fans.

out4- (brown PWM wire from 4028 fan)
out4.tach (yellow sensor wire from 4028 fan)
V_OUTLC1+ (not used, already connected to buck converter)
Ground (not used, already connected to buck converter)

Phaedrux

@rogerpodacter said in Ratrig Vcore 3.1 4028 Fan and Duet 3 Mini 5+ - Current Draw:

Sanyo SanAce40 fan 9GAX0412P3S001

64 dBA

!!!

RogerPodacter

@phaedrux

I know, but i wont be using all that power and will mostly keep it very low. Just nice to know i have it if needed.

My issue still kinda remains, i cannot have this fan completely off between 0-20%, it stays at 8000 RPM. From my research, this is part of the standard where many manufacturers dont define hard requirements in this range. But surely there must be a work around. Right now the printer/fan combo is not usable because this loud fan is always on even when i tell it to turn off.

dc42

@rogerpodacter according to the datasheet at https://docs.rs-online.com/f732/0900766b815bd5ae.pdf the 9GAX0412P3S001 should not rotate at zero PWM; whereas the 9GAX0412P3S003 will rotate at 7800 rpm. Have you checked which version you have?

RogerPodacter

@dc42 thanks I missed that in the manual. I definitely have the 001 model, here is a pic I took.

EDIT: i am on firmware version 3.4.

So I think my setup and wiring must still be incorrect. I will reply with my gcode when I get to work.

EDIT: here is my fan config.g file. Fan0 is my server PWM 4 pin fan.

; Fans
;M950 F0 C"out4" Q500                   ; create fan 0 on pin out4 and set its frequency
M950 F0 C"!out4+out4.tach" Q25000
M106 P0 C"Layer Fan" S0 L0.0 X1.0 H-1
;M106 P0 C"Layer Fan" S0 H-1            ; set fan 0 name and value. Thermostatic control is turned off
M950 F1 C"out3" Q500                   ; create fan 1 on pin out3 and set its frequency
M106 P1 C"Hotend Fan" S0 H1 T45        ; set fan 1 name and value. Thermostatic control turned on

My wiring is as follows:

GND (open not connected, fan black wire goes to buck converter)
V_OUTLC1+ (open not connected, fan red wire goes to buck converter)
out4.tach (fan yellow tach sensor wire connects here)
out4- (fan brown PWM wire connects here)

everything seems to work normal, but just the scale of the PWM is not quite right.

4028 server fan.jpg

dc42

@rogerpodacter that sounds good, assuming your buck converter output ground is common with its input ground.

You could try temporarily connecting the fan PWM input to ground (i.e. brown wire to black wire instead of to out4-) to see whether the fan turns off.

RogerPodacter

@dc42 I just grounded the PWM wire and the fan still spins at around 8000 RPM. Is it possible i damaged the fan? i do recall i first connected the fan and did not have out3 inverted, and the entire board and power supply went dark when i turned on the printer. But i simply unplugged, corrected, and then plugged in and seemingly no damage. But maybe that is the issue?

I somewhat suspect its something else. But definitely right now it seems to be the fan moreso than the board or the settings.

RogerPodacter

I just received a new fan, AVC Model DBTB0428B2G 12 volt 1 amp 4-wire PWM fan, and the behavior is identical to the San Ace fan. This new fan is a 15,000 RPM fan, but it spins at 2,000 RPM on idle at 0%. It also ramps up very unevenly, but it does reach 15,000 RPM at 100% so that's good. i will ground the control pin and see if that changes the behavior.

Is it possible the PWM 4 wire protocol is somehow not functioning correctly? Or is it possible my board is damaged/malfunctioning?

I guess perhaps i could test by using out3 instead of out4 to rule that out?

EDIT: grounding the PWM control wire does not stop the fan, it still spins slowly. Maybe this new model fan has this behavior by default? i couldnt find the datasheet. this just seems so strange.

dc42

@rogerpodacter it's common for fans to spin at a minimum speed even when you feed them 0% PWM through the PWM input (i.e. ground it). However, Noctua fans do turn off, and the datasheet for the -001 variant of your original fan says it is supposed to turn off too.

RogerPodacter

@dc42 Just to close this topic, RatRig seems to confirm they got a bad order of 4028 fans which were really 003's labeled as 001's. So here i am thinking i'm crazy or wiring incorrectly. Anyone who reads this in the future maybe will have an easier time!