Add cooling fan to CRS-326-24P-2S+ ?

incagarcilaso · Wed Feb 10, 2021 5:58 pm

Has anyone done this? Do MT supply fans for the CRS-326? Most MT devices run quite hot and with the MT RJ01 10G interfaces I would prefer to have a fan running in this. Currently the SFP interfaces are at 87 degrees C. I notice the switch is prepared with a fan vent on the body.
Any pointers would be appreciated.

msatter · Wed Feb 10, 2021 8:14 pm

Using search delivered a starting point: viewtopic.php?f=3&t=122395&p=775840&hil ... fp#p780464

incagarcilaso · Thu Feb 11, 2021 10:05 am

Using search delivered a starting point: viewtopic.php?f=3&t=122395&p=775840&hil ... fp#p780464

That's useful, thanks.
Any other experiences with this modification to the CRS-326 would be useful to have.

mvdswaluw · Sat Feb 13, 2021 5:18 pm

viewtopic.php?f=3&t=160063

At the moment my CPU is at 69-70 degrees with an ambient temp of 21 degrees.

I'm planning to also install a fan in my CRS-326. Probably a Noctua FLX fan that I will reduce in speed by adding some resistors in series with the power supply.
I might even install a small switch on the front of the router to switch between high/low RPM's.

While I'm at is I'll also install an internal (12V/36W) power supply.
https://www.instructables.com/Mod-Inter ... S326-24G-/

And some heatsinks on the SFP cages.
viewtopic.php?t=132258

This way I hopefully only need to open and service it just once in his lifetime..

incagarcilaso · Tue Feb 16, 2021 10:57 am

viewtopic.php?f=3&t=160063

At the moment my CPU is at 69-70 degrees with an ambient temp of 21 degrees.

I'm planning to also install a fan in my CRS-326. Probably a Noctua FLX fan that I will reduce in speed by adding some resistors in series with the power supply.
I might even install a small switch on the front of the router to switch between high/low RPM's.

While I'm at is I'll also install an internal (12V/36W) power supply.
https://www.instructables.com/Mod-Inter ... S326-24G-/

And some heatsinks on the SFP cages.
viewtopic.php?t=132258

This way I hopefully only need to open and service it just once in his lifetime..

Thanks for the info @mvdswaluw . I'm having trouble sourcing a fan. There are so many out there that I don't know which would be best on quality and some are supplied without connectors. I found Noctuas but could not find any at 24V. Is your Noctua 24V? Can you use a 12V fan on that board using the free J2 connector? If a fan is supplied without a connector, are they easy to fit? I don't have many tools and if I have to buy these just to fit a connector (I probably won't use the tools again) the price of the switch begins to rise. Not sure how easy it is to fit the connectors.
It's a shame that with the fan connected to the board it doesn't run if the switch is supplied via PoE. I suppose there is no way round that?

mvdswaluw · Tue Feb 16, 2021 4:47 pm

Thanks for the info @mvdswaluw . I'm having trouble sourcing a fan. There are so many out there that I don't know which would be best on quality and some are supplied without connectors. I found Noctuas but could not find any at 24V. Is your Noctua 24V? Can you use a 12V fan on that board using the free J2 connector? If a fan is supplied without a connector, are they easy to fit? I don't have many tools and if I have to buy these just to fit a connector (I probably won't use the tools again) the price of the switch begins to rise. Not sure how easy it is to fit the connectors.
It's a shame that with the fan connected to the board it doesn't run if the switch is supplied via PoE. I suppose there is no way round that?

I'll add a few resistors in line with the power connection of the fan to drop the voltage. See this https://www.youtube.com/watch?v=vjL38udVS24 link why.
I have three 1 Watt resistors that I will use so they won't get as hot as in the clip. Also I will mount them somewhere in the airflow.

SpartanX · Wed Feb 17, 2021 4:37 am

Do you realise that the Noctua FLX fans usually come with a speed-reducing adapter cable (with a built in resistor that's just right)?

You certainly don't need multiple 1W resistors, at least if you are powering the fan from that 12V PSU you mentioned. I would not power a 12V fan from 24V even with dropping resistors because the fans draw current in pulses so would most likely experience overvoltage anyway.

I've just made myself a PiHole box inside a recycled old switch case, with two Raspberry Pi running PiHole, powered from the 12V PSU that was in the switch. Two Noctua fans in it are controlled by a Tasmota programmed 4-channel relay card so I can switch them off/low-speed/full-speed by remote or let the Pi control them from its own temperature monitor.

As soon as another Noctua arrives (this week) I'm adding it, with a PWM controller this time, and a PSU to my RB3011.

incagarcilaso · Wed Feb 17, 2021 10:17 am

Do you realise that the Noctua FLX fans usually come with a speed-reducing adapter cable (with a built in resistor that's just right)?

I didn't know that. So do you think that I will be able to fit a Noctua FLX directly to the 24V board with this reduction cable? I would rather not add a DC-DC step down box as well as the fan because it just adds unnecessary complexity and another point of failure.
I have seen several comments on various forums about the quality of Noctua but unavailability for 24v boards.
If you think the speed step down cable supplied with the fan means I can fit it directly to the free J2 on the CRS-326 board then I might try it. But for me speed reduction is not necessarily voltage reduction - although it may well work.
Thanks.

anav · Wed Feb 17, 2021 2:52 pm

I put those mini heat sinks on all my SFP to copper cage locations, seems to work well.
The CCR1009 does get very hot and have toyed with the idea of a fan for that but too chicken to try it.

incagarcilaso · Wed Feb 17, 2021 3:26 pm

I put those mini heat sinks on all my SFP to copper cage locations, seems to work well.
The CCR1009 does get very hot and have toyed with the idea of a fan for that but too chicken to try it.

:-)
Which mini heat sinks are they? Could you send a reference?

SpartanX · Wed Feb 17, 2021 3:34 pm

So do you think that I will be able to fit a Noctua FLX directly to the 24V board with this reduction cable?

No, that's not what I said. It's for 12V only. You said in your previous post you were going to add a 12V power supply; that will run the fan. I would not connect a 12V fan to 24V even with a resistor - see my previous post for why. You might get away with it and the fan will survive, but I would not do it myself.

Perhaps I misunderstood your intent, with the 12V PSU.

mvdswaluw · Wed Feb 17, 2021 5:27 pm

Perhaps I misunderstood your intent, with the 12V PSU.

Personally I will install a 12V 35Watt supply and install resistors to limit the RPM's of the fan.
In my opinion there is no need to run a fan at 100% speed if the CPU temps ar OK at a lower speed.
Running at 100% will only generate more noise and wear down the fan faster Also accumulation of dust will be reduced with less airflow.

The fan is in backorder. Once received I will measure the voltage with an oscilloscope to see if you are right with your hypothese that the voltages will still spike. I doubt it, but I'll check.

anav · Wed Feb 17, 2021 5:29 pm

Sure,
https://www.amazon.ca/gp/product/B07Q8R ... UTF8&psc=1 (this is what I got)

Similar
https://www.amazon.com/Raspberry-Heatsi ... 72&sr=8-13
https://www.amazon.com/Raspberry-Heatsi ... 642&sr=8-4

mvdswaluw · Wed Feb 17, 2021 5:33 pm

Or this:

https://www.reichelt.com/de/en/heat-sin ... 64359.html

SpartanX · Wed Feb 17, 2021 6:34 pm

Once received I will measure the voltage with an oscilloscope to see if you are right with your hypothese that the voltages will still spike. I doubt it, but I'll check.

I would be interested to see. I disposed of most of my electronics kit, DSOs included, a year back when I decided I no longer needed it all.

TI have already done this though. Take a look at this app note which shows some current graphs for BLDC fans: https://e2e.ti.com/cfs-file/__key/commu ... ART-UP.pdf

Even at startup, the current drawn by the fan ramps up, so the voltage across the dropping resistor will be low at first. I.e. the voltage across the fan will be high. BLDC fans are not linear loads. Like I said, you might well get away with a resistor and the fan will survive (we are only talking low voltages/currents after all) but I would rather not have to replace an expensive fan early because of it. (Noctua fans are expensive to me, although I rarely buy anything else.)

incagarcilaso · Wed Feb 17, 2021 6:51 pm

So do you think that I will be able to fit a Noctua FLX directly to the 24V board with this reduction cable?
No, that's not what I said. It's for 12V only. You said in your previous post you were going to add a 12V power supply; that will run the fan. I would not connect a 12V fan to 24V even with a resistor - see my previous post for why. You might get away with it and the fan will survive, but I would not do it myself.

Perhaps I misunderstood your intent, with the 12V PSU.

The confusion is because the 12V PSU installation was somebody else's post in this thread, not mine. I just intend to add cooling at the moment. Adding internal PSUs is far too advanced for me.

incagarcilaso · Wed Feb 17, 2021 6:53 pm

Or this:

https://www.reichelt.com/de/en/heat-sin ... 64359.html

Great, thanks. I'm in Spain so will see if I can source these or something similar. Amazon is different in each country. I couldn't find the one's referenced in early posts or other threads. I don't want to buy junk, as sometimes happens with Amazon.

incagarcilaso · Wed Feb 17, 2021 6:57 pm

Sure,
https://www.amazon.ca/gp/product/B07Q8R ... UTF8&psc=1 (this is what I got)

Similar
https://www.amazon.com/Raspberry-Heatsi ... 72&sr=8-13
https://www.amazon.com/Raspberry-Heatsi ... 642&sr=8-4

OK, thanks anav.

incagarcilaso · Wed Feb 17, 2021 7:38 pm

OK, so before going ahead and ordering cooling equipment I was taking a look at the board for the CRS326-24G using the high res image on the MT website. I cannot see where the connector for the fan is. Can anyone mark it for me on here? From a previous post I had understood that the board was ready to add a fan with a 3-pin connector.

crs326-24g.JPG

msatter · Wed Feb 17, 2021 7:57 pm

OK, so before going ahead and ordering cooling equipment I was taking a look at the board for the CRS326-24G using the high res image on the MT website. I cannot see where the connector for the fan is. Can anyone mark it for me on here? From a previous post I had understood that the board was ready to add a fan with a 3-pin connector.
crs326-24g.JPG

Do you remember my posting? It's shown in the pictures of that topic.

Two pins, plus and minus.

anav · Wed Feb 17, 2021 8:01 pm

Heh, not to hard to find something.
https://www.amazon.es/Aukru-Disipador-h ... 822&sr=8-8

I know what you are thinking!!!!
Gracias, tu llama real y amada

incagarcilaso · Wed Feb 17, 2021 10:48 pm

OK, so before going ahead and ordering cooling equipment I was taking a look at the board for the CRS326-24G using the high res image on the MT website. I cannot see where the connector for the fan is. Can anyone mark it for me on here? From a previous post I had understood that the board was ready to add a fan with a 3-pin connector.
crs326-24g.JPG
Do you remember my posting? It's shown in the pictures of that topic.

Two pins, plus and minus.

I remember it but can't find it now. There are so many! Please send a link if you can or just the photo.

incagarcilaso · Wed Feb 17, 2021 10:49 pm

Heh, not to hard to find something.
https://www.amazon.es/Aukru-Disipador-h ... 822&sr=8-8

I know what you are thinking!!!!
Gracias, tu llama real y amada

Hey. Better than my search results. Thanks.

msatter · Thu Feb 18, 2021 12:33 am

OK, so before going ahead and ordering cooling equipment I was taking a look at the board for the CRS326-24G using the high res image on the MT website. I cannot see where the connector for the fan is. Can anyone mark it for me on here? From a previous post I had understood that the board was ready to add a fan with a 3-pin connector.
crs326-24g.JPG
Do you remember my posting? It's shown in the pictures of that topic.

Two pins, plus and minus.
I remember it but can't find it now. There are so many! Please send a link if you can or just the photo.

That are two+two soldering points for extra power inputs. The plus is the one closest to the connector and you see the resistor which connrcts to the plus.

If you are not comfortable with soldering look at a splitter cable to be fitted in between the power cable and the power in connector. The fan comes with resitors cables.

The rj01 is known for his heat and there a different heatsinks that have bigger ribs.

viewtopic.php?f=3&t=132258&p=811123&hil ... ng#p656555

anav · Thu Feb 18, 2021 3:33 am

Do you know if anyone has added a fan to a CCR1009??

msatter · Thu Feb 18, 2021 12:25 pm

No and forum also not know that. But you can add a small fan on outside to suck air out close to the position of the SFP.

Seen from the back. Front right side. Powering the fan externally.
If you also using those HOT copper network SFP put also a heatsink on the outside.

anav · Thu Feb 18, 2021 2:47 pm

Yes I do use mini heat sinks on the SFP ports.
Do you mean a fan sucking air away from the large heat sink on the outside of the unit??

incagarcilaso · Thu Feb 18, 2021 8:12 pm

Yes I do use mini heat sinks on the SFP ports.

Out of interest Anav, are those copper pipes (or heat pipes) your own retrofit or were they already fitted?

anav · Thu Feb 18, 2021 9:50 pm

No NO, that looks like a stock picture of inside the CCR1009. It has those BIG copper pipes leading to the heat sink with large fins. THe fins get really hot, I think I could use them for cooking LOL.

msatter · Fri Feb 19, 2021 1:14 pm

Screenshot_20210219_121343.jpg

anav · Fri Feb 19, 2021 2:52 pm

Okay I see, the orange X, is where you recommend I somehow attach a fan to the unit to suck air out.

A. how to attach it to the unit?
B. how to power it?

I recently soldered new capacitors into a zyxel unmanaged switch so have some basic skills, just need pointing in the right direction.

incagarcilaso · Fri Feb 19, 2021 3:47 pm

That are two+two soldering points for extra power inputs. The plus is the one closest to the connector and you see the resistor which connrcts to the plus.

If you are not comfortable with soldering look at a splitter cable to be fitted in between the power cable and the power in connector. The fan comes with resitors cables.

OK, I think I see that, although the image is a little unclear. Could you confirm I have understood you correctly by taking a look at the image below? You say that each of those is a 24V outlet and the positive is on the left in each case? What is the max. current for each of these? If you don't use a resistor would you just solder the cable directly to those points?
I am wondering now whether it might be easier (i.e. less physical modification to the board) to fit an internal PDU and power the fan directly from that, either with a splitter or using a twin output PDU, in combination with a step down DC-DC buck converter in line to the fan.

crs326-24gSalidasextra.JPG

incagarcilaso · Fri Feb 19, 2021 3:51 pm

No NO, that looks like a stock picture of inside the CCR1009. It has those BIG copper pipes leading to the heat sink with large fins. THe fins get really hot, I think I could use them for cooking LOL.

Ah, thought it was your image. Apparently the copper pipes work very well and the so-called "heat pipes" even better. Having seen this, I'm wondering whether just to add additional passive cooling with copper pipes and an external heat sink to my CRS-326.

mvdswaluw · Fri Feb 19, 2021 6:11 pm

I've just received my 12V Noctua FLX fan.
I just powered it from a 18V supply with 330ohm resistance in series with the positive line.
This is what I measured on the connection of the fan during power up.
As you can see there is no voltage spike above the 10.8 Volt. On average the voltage on the fan was about 7.5 Volt.
I'm confident that you can use this fan with a dropper resistor if needed

(I will use it to lower my RPM's, if the airflow is not enough I can take the resistor out, as I will power my switch with an internal 12V supply).

DS1Z_QuickPrint2.png

msatter · Fri Feb 19, 2021 7:50 pm

If you are looking for the fan soldering pads and looked at the bigger versions of the 1009 which share the same boards. Just looking at pictures on the internet.

Screenshot_20210219_184150.jpg

There are no components around those pad so likely also no power on the pads.

I would advise a power source coming from the outside. You can stick the fan on with little pieces of doublesided sticky tape.

If you look at the holes in the housing the flow of heat is mainly to the front. The heat of the processor is transfered to the heat sink at the back.

msatter · Fri Feb 19, 2021 8:12 pm

Screenshot_20210219_190901.jpg

I assume the pads in the red squares are connected and in the blue circle you see the fan connectors with some componend soldered.

This is the 1009 with a bigger case and two internal power supplies.

anav · Fri Feb 19, 2021 9:19 pm

Why 3 wires? I see a + and - on the previous diagram what is the third soldered spot for, closest to the back of the chassis??
I suppose one could check if they are powered by hooking up a multimeter? I wonder if that capacitor close by (11 oclock)is affiliated or not...........

msatter · Fri Feb 19, 2021 11:00 pm

Why 3 wires? I see a + and - on the previous diagram what is the third soldered spot for, closest to the back of the chassis??
I suppose one could check if they are powered by hooking up a multimeter? I wonder if that capacitor close by (11 oclock)is affiliated or not...........

The third pin is there to know the rotating speed of the fan.
https://www.howtogeek.com/273575/what-i ... -cpu-fans/

It could be that the power is present and that the components are there to interpreted the rotating speed. But then if you seek 12V then those two of three pads is a good try.

anav · Sat Feb 20, 2021 12:05 am

Okay but looking at fans, I see we can get USB fans but what is ideal.....................
This looks Really promising,
Roughly 6 inches wide, 2.4 inches high and 1.5 inches deep

https://www.amazon.ca/Portable-Reducing ... cs&sr=1-17

https://www.amazon.ca/Cooling-Xbox-Cons ... 86&sr=8-11

could the USB port on the MT run the fan LOL??
both require 5V, this is not noted on MT unit :-(
One fan requires .7A, the other 1A, seeing as the MT puts out 1A, the first one is more likely to work??

msatter · Sat Feb 20, 2021 1:20 pm

I can't stand Amazon stuff anymore, however I posted earlier about other fans.

viewtopic.php?f=3&t=132258&p=811123&hil ... ng#p811167

anav · Sat Feb 20, 2021 2:35 pm

Yes, those are very nice fans, dont see any USB connectors however and they are too big.
Ended up getting this pair, and I have three UPS where the Router is located and two have USB ports.
https://www.amazon.ca/gp/product/B00IJ2 ... UTF8&psc=1

Dont need them now, its winter and its 12 Celcius in there at the moment, router luvs it.
Come Summer though, will need the fans.

mvdswaluw · Sun Feb 21, 2021 1:19 am

I've just installed my internal 12V power supply, stuck heatsinks on the SFP cages and mounted the Noctua FLX fan (with stock low noise adapter).
I'm glad to report that the CPU on my switch now reports 38-39degrees Celcius instead of 64-68 degrees.

Mikrotik_Router_Temp-pinpoint=1613739728,1613868953.png

For anyone who also want to monitor the temp with Munin, here is my dirty plugin:

#!/bin/sh

case $1 in
   config)
        cat <<'EOM'

update_rate 60
graph_data_size custom 1d, 1m for 1w, 5m for 1t, 15m for 1y

graph_title Mikrotik Router Temp
graph_vlabel degrees C

temp.label      Celcius
temp.warning 80

temp.draw       LINE1

EOM
        exit 0;;
esac

printf "temp.value "; ssh -o StrictHostKeyChecking=no admin@192.168.1.10 'system health print'|cut -d":" -f2|grep -o '[0-9]\+'

mvdswaluw · Sun Feb 21, 2021 1:45 am

By the way, if you want to use the unpopulated redundant power connections/.The right pads miss the diode on the PCB. So connecting there will not work.

CRS326_diode.PNG

anav · Wed Feb 24, 2021 10:34 pm

I just got a TP link switch with a fan. I noticed that is seems to suck air on one side and push air out the other side.
So.......... for the two small 3 Inch fans I bought for the exterior of the CCR1009, should I put one fan on one side blowing air into the unit and one on the other side reverse the fan to suck air out.
Would this be better or same as putting both fans at one end sucking air?? For those experts on the subject ;-PP

mkx · Wed Feb 24, 2021 10:51 pm

It's the matter of controlling air flow. If there are only "suckers" at one side, then air will escape the unit everywhere. If you have a "sucker" and a "pusher", then air will mostly flow between the two fans. If device case and device internals are designed to force air flow in certain direction, then dual fans are not necessary, a single fan somewhere inside device can do the job.

incagarcilaso · Fri Feb 26, 2021 6:26 pm

By the way, if you want to use the unpopulated redundant power connections/.The right pads miss the diode on the PCB. So connecting there will not work.

That's good to know! So only the one on the left works? So you installed a 12V power supply JUST for the fans? You will have two power sources running to the switch then? One for the switch board and one just for the fans?
"There is more than one way to skin a cat". This thread has offered 3 or 4 different ways to add active cooling to the CRS-326.

mvdswaluw · Fri Feb 26, 2021 8:45 pm

I installed one 12V power supply and it powers both the switch and fan. I’m feeding the router from the left pads where I’ve soldered wires on to.

incagarcilaso · Mon Mar 01, 2021 12:40 pm

I installed one 12V power supply and it powers both the switch and fan. I’m feeding the router from the left pads where I’ve soldered wires on to.

Forgive what might seem a silly question but this really isn't my area.
Are we both talking about the CRS-326? So I see that it marks a voltage input range on the box at the back from 10V-30V but I was under the impression that it had to be powered with 24V, mainly because it ships with the AC 230V to DC 24V adaptor.
If it does accept a 12V power supply then of course it saves hassle adding a buck converter to step down to 12V for the fans I want to install. However, if the main board can run with a 12V power supply and we do that are we not just adding more heat to the whole board because lower voltage = higher amperage? Or perhaps that is not significant enough to create more heat.
If this can be run on a 12V supply then I will probably install a 12V internal power supply and use that to power the main box as well as the fans I add.
Would be good to know for sure.

mvdswaluw · Mon Mar 01, 2021 1:00 pm

If I analyse the PCB correctly the 10-30V is stepped down to a lower voltage with a switched mode power supply. These do normally not generate a lot of heat.
My switch, with the fan on a lower than stock speed and an internal 12V Meanwell supply runs nice and cool now.

20210301_Mikrotik_Temps.png

incagarcilaso · Mon Mar 01, 2021 1:34 pm

If I analyse the PCB correctly the 10-30V is stepped down to a lower voltage with a switched mode power supply. These do normally not generate a lot of heat.
My switch, with the fan on a lower than stock speed and an internal 12V Meanwell supply runs nice and cool now.

OK, thanks. I think I'm going to try that.

sindy · Mon Mar 01, 2021 1:50 pm

if the main board can run with a 12V power supply and we do that are we not just adding more heat to the whole board because lower voltage = higher amperage? Or perhaps that is not significant enough to create more heat.

The heat is the dissipated power, and power is a product of voltage and current (amps). So it doesn't matter whether the device drains 2 A from 12 V or 1 A from 24 V. But the loss (and thus generated heat, although it is not noticeable under normal circumstances) on the feeding wires depends only on the current and the cross-section of the wires (which determines their resistance), so using higher voltage and thus lower current makes sense when using the thin wires in Ethernet cables to deliver power, which explains why the adaptor bundled with most Mikrotik models is a 24 V one.