I don't know why you would really want them to run any slower, at the minimum speed they generate very little pressure. The thing is, that all D5's are made by Laing and even though some have different features the core components are identical.
The USB d5 just uses a digital interface tacked on to to the original D5 Vario control board inside the pump. The digital speed controller manipulates the same circuits that the simple dial controller on standard D5's does ... therefore you get the same min and max speeds. I opened my D5 USB and my Koolance PMP450 and they had the same board.

Only the Swiftech Pump PWM D5 with its PWM control seems to be different but I have not seen inside one of those to look at the control board.

Zitat von »Barney Gumble«

I have been testing & learning with the aquaero 5 LT; plus 2 D5s and 1 MPS400. Great stuff overall. The 2 D5s are mounted in an XSPC dual reservoir.

What type of D5 pump do you have...the normal analog one with the little red rotary potentiometer...

...or the digital USB/Aquabus controlled D5 from Aquacomputer?

Zitat von »Barney Gumble«

One thing I have found is the the D5s seem to have a minimum power/speed of 25% (resulting in about 1800 rpm) and I can't change this. Is this on purpose, if so why, and is there any way to change it? I mostly feel I should have max control if I want.

Thanks.

The RPM can be changed with the little red poti from 1 (slow) to 5 (fast) for the analog controlled D5 and via USB or Aquabus connection for the digital conntrolled AC D5 with the software Aquasuite 2013. If you want to use the Aquabus, you need to plug the pumps via USB first and must set two differnent device IDs (only possible with a USB connection and the Aquasuite software). After that you can connect the pumps via Aquabus. Now the pumps should be integrated in the Aquaero menues...I think.

None of those things are very restrictive at all, as soon as you add a CPU block the flow rate will fall right down.

25% of total available volts isn't the same as "25% speed", technically. Every DC powered device, be it a fan or pump, has two important voltages to keep in mind:

1. Minimum starting voltage. This is the voltage required to get the thing spinning from a dead stop. My Yate Loon fans have a minimum starting voltage of around 3.6 volts, for example.

2. Minimum operating voltage. This is the minimum voltage that can be applied to a device and still have it function (spin). My Yate Loon fans can operate down to around 2.2-2.3 volts. That's about 19% on the power scale, but 1% on the speed scale. See how they don't match up?

The first is important to know, as if you're using a device intermittently (my fans are set up this way), you need to apply that voltage or slightly less in order for it to start successfully. The second is important as, if you want the device to continue to run, operating voltage must never dip below this number.

This plays into the fan setup in Aquasuite. Your pumps will likely run continuously, so you'll check the "hold minimum power" box. Then you'll want to set the minimum voltage to a number that's maybe 0.1 volts higher than minimum operating voltage for safety. You check "Use Startboost" under "Advanced" to make sure it gets enough voltage to start initially.

Since your pumps aren't cooling anything right now, you can play with the voltages and find the absolute minimums for voltage. Be aware that once you add all tubing and blocks to the loop that you might need to apply slightly more voltage due to resistance in the loop. If you're able to keep the pump spinning at 25% of 12V right now, that's only 3 volts, and that's fairly low voltage. Most pumps and fans don't like to operate at voltages less than 3 volts. Most stop spinning somewhere at less than 3 volts minimum operating voltage. I imagine the pump has got to be silent or very nearly silent at that speed anyway, so I wouldn't sweat it if it won't go lower. You'll want the pump spinning faster anyway, as the flow is pretty low at the bottom of the speed curve.

Zitat von »Jeremy«

25% of total available volts isn't the same as "25% speed", technically. Every DC powered device, be it a fan or pump, has two important voltages to keep in mind:

1. Minimum starting voltage. This is the voltage required to get the thing spinning from a dead stop. My Yate Loon fans have a minimum starting voltage of around 3.6 volts, for example.

2. Minimum operating voltage. This is the minimum voltage that can be applied to a device and still have it function (spin). My Yate Loon fans can operate down to around 2.2-2.3 volts. That's about 19% on the power scale, but 1% on the speed scale. See how they don't match up?

The first is important to know, as if you're using a device intermittently (my fans are set up this way), you need to apply that voltage or slightly less in order for it to start successfully. The second is important as, if you want the device to continue to run, operating voltage must never dip below this number.

This plays into the fan setup in Aquasuite. Your pumps will likely run continuously, so you'll check the "hold minimum power" box. Then you'll want to set the minimum voltage to a number that's maybe 0.1 volts higher than minimum operating voltage for safety. You check "Use Startboost" under "Advanced" to make sure it gets enough voltage to start initially.

Since your pumps aren't cooling anything right now, you can play with the voltages and find the absolute minimums for voltage. Be aware that once you add all tubing and blocks to the loop that you might need to apply slightly more voltage due to resistance in the loop. If you're able to keep the pump spinning at 25% of 12V right now, that's only 3 volts, and that's fairly low voltage. Most pumps and fans don't like to operate at voltages less than 3 volts. Most stop spinning somewhere at less than 3 volts minimum operating voltage. I imagine the pump has got to be silent or very nearly silent at that speed anyway, so I wouldn't sweat it if it won't go lower. You'll want the pump spinning faster anyway, as the flow is pretty low at the bottom of the speed curve.

My D5s all stop running under 6.8v and wont start with less than 7.2v keep this in mind and set a minimum pump voltage of 7.2v to be safe. You may need to check your pumps though as a different pressure in the loop may effect your startup and running voltages.

Zitat von »Phatboy69«

My D5s all stop running under 6.8v and wont start with less than 7.2v keep this in mind and set a minimum pump voltage of 7.2v to be safe. You may need to check your pumps though as a different pressure in the loop may effect your startup and running voltages.

Mine shut down around 7.4 volts.

Every individual device, even from the same family or group of products, will have its own personality and limits due to tolerances in manufacturing and application differences. The only way to find the absolute limits for your specific device is via testing and experimentation.

The USB D5 pumps aren't voltage controlled anyway. They have an internal motor controller just like the D5 Vario, that has a set minimum speed of 1800RPM that equates to the 25% power setting in Aquasuite.

Zitat von »Jakusonfire«

The USB D5 pumps aren't voltage controlled anyway. They have an internal motor controller just like the D5 Vario, that has a set minimum speed of 1800RPM that equates to the 25% power setting in Aquasuite.

I have the vario D5s and they voltage control just fine with them set on 5. They just dont spin as slow as when using the built in 5 settings on the control switch.

Hi there. I can't hit RPMs below 2800 via aquaero 6 voltage regulation for D5 vario pump (one step below and pump shutting down).
Manual regulation by potentiometer has 1800RPM minimum.
Any reason for that behavior?

this is normal.
Use the PWM pump for controlling the speed.

Zitat von »denny«

Hi there. I can't hit RPMs below 2800 via aquaero 6 voltage regulation for D5 vario pump (one step below and pump shutting down).
Manual regulation by potentiometer has 1800RPM minimum.
Any reason for that behavior?

Yes there is a good reason.

There is two common ways to control motor speed. Voltage control and pwm.
Voltage control just lowers the voltage supplied to the pump while pwm switches the power on and off rapidly while maintaining full voltage to simulate the effect of lowered voltage.
Lowering voltage reduces the power and torque the pump can produce whereas pwm lowers the power output while keeping all the torque. The result is that the electric motor can spin to a lower speed using pwm than voltage control.

The dial in the back of the d5 Vario is a pwm setting control that the pumps internal pwm motor control uses.

You will see the same affect with pwm fans of you try to voltage control them. The speed range is much reduced.