pwm water pump header question

[blackestvoid]

realised that d5 and ddc pumps have separated the power (using molex) from pwm (pwm header)

the pwm header can provide power to the pump as well

why are the power wires separated from pwm and require separate connectors?


is it due to olden days where fan headers are unable to provide sufficient power?

 

[wwenze]

Because pump draws more current than the motherboard can supply.

 

[blackestvoid]

suspect so and those are in olden days
but if current motherboard headers can provide sufficient amp needed by the pump (according to tech spec) so should be safe to discard the molex and use just pwm fan header right?
had seen some motherboards specifically the pwm headers as fan/pump
also using additional molex cable is bad for cable management as the pump is the only component using molex

 

[commach]

Check the current requirement of the pump, if the PWN fan connector able to provide the require current, you can discard the molex power cord and use the PWM fan connector which is typical 1a output. If the pump required 1a or 0.9a, I suggest you use the molex power cord instead of using the PWM fan connector, using at or near max output is a no go for me, your choice.

They comes with separate power cord is for all user especially older motherboard with under 1a current output fan connector.

 

[wwenze]

So you know how to terminate your own fan connector?

 

[blackestvoid]

Check the current requirement of the pump, if the PWN fan connector able to provide the require current, you can discard the molex power cord and use the PWM fan connector which is typical 1a output. If the pump required 1a or 0.9a, I suggest you use the molex power cord instead of using the PWM fan connector, using at or near max output is a no go for me, your choice.

They comes with separate power cord is for all user especially older motherboard with under 1a current output fan connector.

according to tech specs at max power the pump amp draw matches what the pwm header is able to provide

So you know how to terminate your own fan connector?

ugliest but easiest solution is to get molex to sata connector, then can remove molex cable totally
also looking at molex to pwm header adapter
or find a pwm header to cut and join the power and ground wires
worst case but nicest is to desolder and solder on a proper pwm header

 

[commach]

You better use the molex power cord.

Unless your PSU can supply 24v, running it with 12v is 2a current requirement, not all PWM fan connector capable of 2a output.

 

[blackestvoid]

You better use the molex power cord.

Unless your PSU can supply 24v, running it with 12v is 2a current requirement, not all PWM fan connector capable of 2a output.

this is d5 pump? it uses more amp
my pump draws 1.5a and the pwm header can provide 1.5a
according to specs

 

[commach]

this is d5 pump? it uses more amp
my pump draws 1.5a and the pwm header can provide 1.5a
according to specs

Yes, D5 pump according to this.

DDC 3.2, 12v operation only at 1.5a

If you preferred using PWN fan connector, avoid running it at top speed to prevent overloading.

 

[blackestvoid]

don't believe the pump will ever be running at full speed, at least not for extended timing, so should be quite safe



even aio are able to use pwm headers instead of molex

 

[commach]

AIO is just a form factor, the key is the current requirement of the BLDC motor. Not all water cooling kit/setup are using the same BLDC motor thus you can't put them on the same yardstick on current requirement.

The same goes to DC stepper motors, NEMA17 stepper motors can range from 0.8a to 2.2a depends on microstep and number of poles.

 

[Encrypted11]

Overall seems like an inconvenience for you to run the molex? You're needing an additional peripheral cable with a molex on it causing cable management clutter?

How about terminating the 12v and ground wire in the molex (d5 only uses these 2) to a PCIe connector if you have the pinout for your PSU cables? Think got people do that including custom loop builders like singularitypc but I could be wrong

 

[blackestvoid]

ya, i'm trying to understand the rationale for the manufacturers still using molex even with new iterations of the pumps
cable management is a headache, molex cable is long, thick and hard

of course if the pump draws more power than what pwm headers can provide it should be connected to the psu and drawing power directly from the psu, but it should ideally be sata and not molex since sata is more common now
is cost the reason? sata connector more costly than molex?

but if the pump is drawing around 1a it should ideally be using pwm header which current generation mobo can provide sufficient power

 

[commach]

Connector form factor is not the main reason why manufacturer refrain from using SATA power connector, the main concern is reverse current that might fried you SATA drives if using the same rail.

All DC motor with permanent magnet can be a generator regardless of brush or brushless. I've been telling friends and clients not to connect fans and drives using the same cable to avoid this problem. In most cases, there isn't any major concern, the problem comes when cleaning the fans using compress air or vacuum cleaner, the fan might spin in a reverse direction and produce enough power to fried the drive connected to the same cable. Even though BLDC water pumps are unlikely to rotate in the reverse direction without changing the firing order of the poles, but as a rule of thumb, the mentality of reverse current protection is always in the mind of electrical/electronic engineer.

Moreover, SATA connector is extremely fragile and it was never design for connecting other device except SATA drives, a poor contact will result in high resistance and heat up the cable and connector, a situation most if not all manufacturers will try to avoid as much as possible.

 

[wwenze]

Terminate your own CPU +12V connector and pull two wires from there to your pump.

Or solder the wires to the +12V points at the underside of the mobo

 

[blackestvoid]

Connector form factor is not the main reason why manufacturer refrain from using SATA power connector, the main concern is reverse current that might fried you SATA drives if using the same rail.

All DC motor with permanent magnet can be a generator regardless of brush or brushless. I've been telling friends and clients not to connect fans and drives using the same cable to avoid this problem. In most cases, there isn't any major concern, the problem comes when cleaning the fans using compress air or vacuum cleaner, the fan might spin in a reverse direction and produce enough power to fried the drive connected to the same cable. Even though BLDC water pumps are unlikely to rotate in the reverse direction without changing the firing order of the poles, but as a rule of thumb, the mentality of reverse current protection is always in the mind of electrical/electronic engineer.

Moreover, SATA connector is extremely fragile and it was never design for connecting other device except SATA drives, a poor contact will result in high resistance and heat up the cable and connector, a situation most if not all manufacturers will try to avoid as much as possible.

excellent explanation
to avoid frying the hdd make sure to disconnect the cables before cleaning
but i personally find sata connections are more secure and smaller than molex
in fact if i have $ i will get m.2 drives and get rid of sata cables as well
only left the 24pin and 8pin power from psu to motherboard

 

[wwenze]

but i personally find sata connections are more secure

Oh rly?

Secureness of connection is correlated with current capability.

Technically Molex can carry much more power than the SATA power connector.

Molex has 2 power pins (one 5V and on 12V pin), each can deliver 11Amps for a total of 22Amps. The other 2 pins are ground wires...

SATA power connectors has a total of 15 pins of which 9 are power pins (3 x 3.3V, 3 x 5V, 3 x 12V). Each pin can carry 1.5Amps for a total of 13.5Amps. BUT as there is as yet no use for the 3.3V pins the effective power available to drives is only 9Amps.

http://www.tomshardware.com/forum/355945-28-does-molex-connector-provide-power-sata-power-connector

 

[blackestvoid]

Oh rly?

Secureness of connection is correlated with current capability.



http://www.tomshardware.com/forum/355945-28-does-molex-connector-provide-power-sata-power-connector

i always have difficulty connecting molex, never had a single successful try, always had to twist and shake a bit before mating correctly

for sata is always 1 shot 1 kill

my concern is fit for purpose
if the pwm header can provide enough juice then its worth a shot as long as the background is understood
looking forward to the day when pumps cables become modular

 

[joshuaho]

Please read through this again and again. I tried the short cut method in the past to bypass molex cables cause it’s shitty, and it’s basically ketchup. Made changes to the sata cable and looped it up together with one of my HDD in my system and a couple months later went for a cleanup.. used compressed air to spray the fan and.. HDD died

All DC motor with permanent magnet can be a generator regardless of brush or brushless. I've been telling friends and clients not to connect fans and drives using the same cable to avoid this problem. In most cases, there isn't any major concern, the problem comes when cleaning the fans using compress air or vacuum cleaner, the fan might spin in a reverse direction and produce enough power to fried the drive connected to the same cable. Even though BLDC water pumps are unlikely to rotate in the reverse direction without changing the firing order of the poles, but as a rule of thumb, the mentality of reverse current protection is always in the mind of electrical/electronic engineer.

Moreover, SATA connector is extremely fragile and it was never design for connecting other device except SATA drives, a poor contact will result in high resistance and heat up the cable and connector, a situation most if not all manufacturers will try to avoid as much as possible.

PM me for cookie (; HardwareZone Forums app

 

[wwenze]

Erm yea but then what happens to PATA HDDs?

I think the issue is more of having a low impedance discharge path than what connector it uses.