[Dire Squirrel]

I'm in the process of putting my first custom loop together, and would like to know if anyone has an idea for a simple and reliable fail-safe for the pump.
What I'm looking for is basically something that will automatically shut down the PC if the pump fails. Ideally it should be able to properly shut down the system, but even just pulling the power would be acceptable.

I have a EK D5 PWM pump that will be hooked up to my fan controller.

 

[fast_fate]

A flow meter of some description is what you're after.
Bitspower and Koolance make models that convert the flow rate into an rpm signal that you can plug into a mobo fan header.

Either set up BIOS so the pc shuts down when under certain rpm
or use software based monitoring to do the same thing, such as speedfan.

If you want to spend a bit more and get the best - with a whole lot more to offer as well, there is only 1 ......
Aquaero 6XT

 

[BadDad62]

My DDC is the same and I just the set bios to shut down at 70*

Flow meters are an unneeded extra $$

 

[larymoencurly]

You don't need a flow meter to detect flow; just measure the temperature on opposite sides of the pump and shut down if the temperature difference is too great. But why worry about pump flow when it's temperature that really matters?

How about taking a conventional heatpipe CPU cooler and mounting the water block on top of its copper plate, and have the heatpipe cooler's fan turn on only at highet temps plus sound an alarm when that happens?

 

[zoid.srg]

newer, high end motherboards have fail safe functionality in the BIOS/UEFI. you can easily set it to turn off the PC in case a fan/pump stops(you need to plug in the RPM signal to the motherboard to do this) or in case the temperature gets to high. I have mine set to turn off if either the pump fails, or the cpu temperature goes over 90°C... of course that hasnt happened to me yet so i have no way to tell if it will acctually work or not.

 

[Jakusonfire]

Quote:

Originally Posted by larymoencurly

You don't need a flow meter to detect flow; just measure the temperature on opposite sides of the pump and shut down if the temperature difference is too great. But why worry about pump flow when it's temperature that really matters?

How about taking a conventional heatpipe CPU cooler and mounting the water block on top of its copper plate, and have the heatpipe cooler's fan turn on only at highet temps plus sound an alarm when that happens?

That wouldn't really work. For starters how do you make a system shut down based on the difference between temps. Second if flow stops then heat just builds up in the water inside the blocks and only very slowly travels to the pump. The temp will still be the same on either side of the pump though.

Flow meters aren't completely necessary normally but they can be very useful for the small cost outlay.

Also I have yet to see a BIOS that will genuinely shut down a system if a pump fails. They have warning settings, but that is all they do, warn. modern CPU's have built in temp based throttling and eventual shut down but throttling and water means that can potentially take a long time.
I have personally seen a case where a guys pumps failed, the water temps kept building til the system ruptured.

 

[Unicr0nhunter]

Wouldn't a flow meter signal be a more reliable fail safe measure than just a pump rpm signal because it would also quickly catch a leak, not just a pump failure. No?

 

[fast_fate]

Quote:

Originally Posted by zoid.srg

newer, high end motherboards have fail safe functionality in the BIOS/UEFI. you can easily set it to turn off the PC in case a fan/pump stops(you need to plug in the RPM signal to the motherboard to do this) or in case the temperature gets to high. I have mine set to turn off if either the pump fails, or the cpu temperature goes over 90°C... of course that hasnt happened to me yet so i have no way to tell if it will acctually work or not.

How can your fail safe be fail safe if you haven't tested it.
You should try - at least the pump power side of it....
Just unplug your pump while the system is operating

Quote:

Originally Posted by Unicr0nhunter

Wouldn't a flow meter signal be a more reliable fail safe measure than just a pump rpm signal because it would also quickly catch a leak, not just a pump failure. No?

Which is exactly why I suggested it.
Maybe not immediately for a leak - but a major failure yes.

RPM monitoring will work great if the pump overheats / burns out and fails OR power to it is interrupted.

The flow meter method will do what the rpm can do AND shut down in the event of a major loop failure.
If loop has a leak (not major failure) and doesn't leak onto anything that caused trip out, will shut down before pump burns out at least.
Personally I'ld rather have a meter's flow signal than just the pump's rpm signal.

I've had Aquaero set so if flow gets lower than XXX it shut's the system down - great
Add a flow meter with rpm converter to the mobo - even better.
and then add the pump's rpm signal to the mobo and you have done all you can.

except maybe with the addition Aquaero's reservoir level / pressure sensor - now that would be an overkill fail safe system - those 4 working for you

 

[zoid.srg]

Quote:

Originally Posted by fast_fate

How can your fail safe be fail safe if you haven't tested it.
You should try - at least the pump power side of it....
Just unplug your pump while the system is operating

Well, thats the thing. You can invest thousands in fail safe equipment, but untill something acctually fails you wont know for sure if it will work... and I do not unplug/plug any connectors while the system is running.

 

[fast_fate]

Quote:

Originally Posted by zoid.srg

Well, thats the thing. You can invest thousands in fail safe equipment, but untill something acctually fails you wont know for sure if it will work... and I do not unplug/plug any connectors while the system is running.

No need to unplug anything while running, sorry

I should have said switch off instead

 

[Maximization]

i use an aqua stream with flow meter unit, you can set limits in the aquasuite software. The bios setting on a mobo react to a heat event on the hardware, the flow rate is allot quicker before heat becomes an issue.

 

[rdr09]

Quote:

Originally Posted by zoid.srg

newer, high end motherboards have fail safe functionality in the BIOS/UEFI. you can easily set it to turn off the PC in case a fan/pump stops(you need to plug in the RPM signal to the motherboard to do this) or in case the temperature gets to high. I have mine set to turn off if either the pump fails, or the cpu temperature goes over 90°C... of course that hasnt happened to me yet so i have no way to tell if it will acctually work or not.

+rep. I set my intel rig to shut down at 80c. You can test it by setting it lower.

 

[Big Elf]

You can also use the 'Alarm EXE setting' in Real Temp to initiate a shutdown if temps exceed a user specified limit for both CPU and GPUs. I have a batch (shutdown.bat) file that runs:

shutdown.exe -s -f -t 00

if the CPU exceeds 70ºC or the GPUs exceed 60ºC.

 

[larymoencurly]

Quote:

Originally Posted by larymoencurly

You don't need a flow meter to detect flow; just measure the temperature on opposite sides of the pump and shut down if the temperature difference is too great. But why worry about pump flow when it's temperature that really matters?

How about taking a conventional heatpipe CPU cooler and mounting the water block on top of its copper plate, and have the heatpipe cooler's fan turn on only at highet temps plus sound an alarm when that happens?

Quote:

Originally Posted by Jakusonfire

That wouldn't really work. For starters how do you make a system shut down based on the difference between temps. Second if flow stops then heat just builds up in the water inside the blocks and only very slowly travels to the pump. The temp will still be the same on either side of the pump though.

LM339 is a simple way. Use one to measure the temperature difference to verify pump flow, another for absolute temperature, and maybe another to take those 2 states and drive an on/off signal. I have some homemade solar water heater controllers like this. Since the LM339 is 5V TTL compatible, you can even feed it the Power-On signal from the PSU to combine it into a combination Power-On/Emergency-Off signal, but that requires cutting into the green Power-On line. Lots of application notes for the LM339 and for comparators in general. It wouldn't surprise me if somebody used a 555 instead. Then there's the Rube Goldberg solution for something simple like this, AKA Arduino.
Quote:

Originally Posted by Jakusonfire

Flow meters aren't completely necessary normally but they can be very useful for the small cost outlay.

Also I have yet to see a BIOS that will genuinely shut down a system if a pump fails. They have warning settings, but that is all they do, warn. modern CPU's have built in temp based throttling and eventual shut down but throttling and water means that can potentially take a long time.
I have personally seen a case where a guys pumps failed, the water temps kept building til the system ruptured.

As I said, who cares about flow when it's temperature that really matters?

If the motherboard BIOS can read temperature from a thermistor, you can the overtemperature shutdown work by shorting that thermistor and faking an overtemperature condition to trigger shutdown. I don't know how to do this with a fan RPM/temperature sensing chip, but it probably requires a connection to the output side of the chip, and I wouldn't want to short that unless the chip was made for shorting (also it probably works on 3.3V instead of 5V). Either such solution can be implemented with just a bimetal thermostat.

Water cooling loops can be built so pump failure won't lead to catastrophe, but it probably requires a reservoir and locating the radiator above the water block to get enough of a thermal siphon.

 

[larymoencurly]

Quote:

Originally Posted by Unicr0nhunter

Wouldn't a flow meter signal be a more reliable fail safe measure than just a pump rpm signal because it would also quickly catch a leak, not just a pump failure. No?

A temperature sensor can also do that. This goes back to my claim that temperature matters more than flow. And a slow leak may take a while to cause overheating. I don't know how to implement leak detection well, but I have installed plastic splash shields (cut up polypropylene storage containers or 2L soda bottles) to prevent shorts.

 

[fast_fate]

OK I agree, temp is one of the major factors for a fail safe consideration.

For a water cooled system let's call the pump the heart of the cooling system.
The cooling system which keeps the temperatures in check.
In this system we have both pump RPM monitoring (BIOS and/or software whichever the user thinks works best) ) AND coolant flow monitoring for a pump fail safe.

Now lets hypothesize that that the pump/s is still working, effectively cooling the system and so an RPM signal fail safe senses no problem.
But there is a leaking fitting in the basement or pedestal which goes undetected by the user.

Which of the fail safe systems will kick in first and shut down the system.

The flow monitor will every time, because it kicks into action before anything has a chance to overheat
and saves the pump at the same time.

 

[RX7-2nr]

1. Install Realtemp to monitor your temperatures. Aside from what I'm about to tell you, it's a great monitoring program.

2. Open the Settings and make an alarm temperature, mine is set to 80C.

3. Next, make a batch file that will immediately shutdown the PC. To do this, open notepad and paste the following
Quote:

shutdown.exe -s -f -t 00

4. When you save it, save it as Shutdown.bat. I saved mine into My Documents so it would be out of the way. If you run this batch file it will immediately shut down your computer.

5. Finally, open Realtemp, Settings, click on Alarm EXE, and set it to your shutdown.bat. It will now run the shutdown batch file as soon as your computer hits the designated alarm temperature.

 

[Big Elf]

I am, apparently, still invisible.

 

[RX7-2nr]

ha

 

[hanzy]

I run two pumps in series.
Mechanical back up.