Sanity Check - DDC Pump

WantoN · 14 Nov 2018 at 21:01

I wired my DDC pump into a fan header, but research has led me to believe that the tach and PWM colours are reversed on DDC pumps.

This is my current configuration, which I believe is wrong; I think I need to swap the blue and green wires.

The pump is a standard generic Laing DDC.

Can someone confirm?

WantoN · 15 Nov 2018 at 14:21

Sadly no replies.

I took a gamble and swapped the wires. The pump is working.

Thought I’d leave this here for posterity.

Jamin280672 · 15 Nov 2018 at 16:21

WantoN said:
Sadly no replies.

I took a gamble and swapped the wires. The pump is working.

Thought I’d leave this here for posterity.

No the original way was the correct way around, just think of how a 3 pin fan plug is wired with the missing pwm cable, that missing cable takes up the 4th spot, the PWM cable.

WantoN · 15 Nov 2018 at 18:15

Jamin280672 said:
No the original way was the correct way around, just think of how a 3 pin fan plug is wired with the missing pwm cable, that missing cable takes up the 4th spot, the PWM cable.

Cheers for posting mate. Is the image you’ve linked from a resource on DDC wiring, or have you wired them that way yourself?

The reason I ask is because I solder fan banks a lot, and I know how they’re usually wired. But everything I can find online suggests that the PWM and tach wire colours are switched on the Laing DDC.

I’ve looked at images of the third party plugs and where they’ve used the OEM wiring scheme you can see that on the 4pin connector the colours of PWM and tach are reversed.

I’m quite confused now.

WantoN · 15 Nov 2018 at 23:44

Well I tried putting them back, and now I get no RPM value. So I’ll be leaving them switched over until I can find a definitive answer.

LuckyBenski · 17 Nov 2018 at 01:23

I usually ignore colour codes and presume that everything comes wired correctly to its plug. The 3 pin and 4 pin headers have pretty much standardised pinout, but the colours are not standardised. Ran into this issue when working with GPU fans too.

fornowagain · 17 Nov 2018 at 01:35

I can tell you 100% on a Laing D5 PWM that the blue is inboard on the 4 pin. That being the rpm signal, pin 3.

And completely opposite to the standard colours. Don't ask...

WantoN · 17 Nov 2018 at 13:45

fornowagain said:
I can tell you 100% on a Laing D5 PWM that the blue is inboard on the 4 pin. That being the rpm signal, pin 3.

And completely opposite to the standard colours. Don't ask...

Thanks, this is what I thought, and what my testing has confirmed. It’s good to know I’ve not gone mental.

Think I’m switching to a D5 if this doesn’t improve with bleeding, it’s bloody noisy.

Bluntwrapped · 19 Nov 2018 at 08:06

Do yourself a favour man and buy a D5 now and toss the DDC. DDC are powerful but sound horrible no matter what you do. Oh and stay away from PWM unless you really need it. A vario D5 with a fixed setting is 100% better.

I’ve always found PWM fans or pumps to be quite noisy, especially when you’re running things low close to the starting voltage. Fixed voltage either through molex or a fan controller is the right way to do things.

From my own experience of PWM I’d advise everyone to avoid it - it’s horrible and innacurate even when it works.

LuckyBenski · 19 Nov 2018 at 09:20

Bluntwrapped said:
Do yourself a favour man and buy a D5 now and toss the DDC. DDC are powerful but sound horrible no matter what you do. Oh and stay away from PWM unless you really need it. A vario D5 with a fixed setting is 100% better.

I’ve always found PWM fans or pumps to be quite noisy, especially when you’re running things low close to the starting voltage. Fixed voltage either through molex or a fan controller is the right way to do things.

From my own experience of PWM I’d advise everyone to avoid it - it’s horrible and innacurate even when it works.

That's an interesting perspective I haven't known about til now. I have an Alphacool VPP755 which has 5 speeds on a Vario switch, and interprets PWM input to select a speed. So, 0-20% PWM will give speed 1, 20-40% will give speed 2 etc. It means the speed only changes in steps rather than ramping up and down.

That said, aside from filling and flushing, fixed pump speed is the way to go IMO. Pump speed doesn't really affect temperatures, it's mostly useful for tailoring it to your loop resistance.

Jamin280672 · 19 Nov 2018 at 10:33

D5 Vario is the way to go if you have the room, they are quite big pumps, the thing I hated with the DDC is they dump their heat into the water, and they are extremely hot little suckers, I know all pumps do this, but they don't get anywhere near as hot as the DDC.

LuckyBenski · 19 Nov 2018 at 12:12

Jamin280672 said:
D5 Vario is the way to go if you have the room, they are quite big pumps, the thing I hated with the DDC is they dump their heat into the water, and they are extremely hot little suckers, I know all pumps do this, but they don't get anywhere near as hot as the DDC.

I'm guessing you mean the D5 dumps heat into the water

almightydutch · 21 Nov 2018 at 09:28

My D5 vario must be 10 years old, at least. Quite simply one of the best purchases for my PC EVER!!

I have a DDC in another machine and while it works ok, it does suffer from the dreaded non starting issue every now and again. That's fun when you only notice it due to CPU temp being astronomical.

WantoN · 21 Nov 2018 at 12:13

You’ve pretty much convinced me. I’ve got the DDC quieter, but it’s still the loudest thing in the system by far.

I’ll see if I can fit a D5 in the new build, and pick one up on the MM if I can.

ubersonic · 21 Nov 2018 at 12:53

Only used a DDC a couple of times as I don't rate them as being in the same league as an Eheim or a D5 Vario. But a quick "fix" for a DDC is to connect it to a cheap molex powered fan controller (like the ones thta are a PCI bracket with speed knob) thus turning them into Vario DDCs.

Bluntwrapped · 21 Nov 2018 at 13:07

WantoN said:
You’ve pretty much convinced me. I’ve got the DDC quieter, but it’s still the loudest thing in the system by far.

I’ll see if I can fit a D5 in the new build, and pick one up on the MM if I can.

Good shout man. I went with a DDC on my last build as space was extremely limited. I found no matter that I tried I could hear the electrical pump whine from the other side of the room.

Depending on your board too, until the bios loads properly all connected PWM bits ramp up to full speed. Fairly minor in itself but in context to the other compromises it was enough to make things even more annoying.

With my D5 I can have it set to max and it’s quieter than any fan I’ve tried.

Brilliant bit of kit