Koolance CTR-SPD10 Pump Speed Controller 8-13V

Posted: March 27, 2011 in Control-Monitor, Fans, Pumps
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Welcome to another pump speed controller (CTR-SPD10), and before you pass by thinking you can get the same thing from any fan controller, take a closer look.  This little analog controller is also built with a transformer so you get slight “Overvolt” capabilities as well as undervolting.  I used these controllers in my pump noise testing because of this ability and they are really well suited to driving the PMP-400  or other DDC pumps that otherwise don’t have speed control.

I would also like to thank Tim from Koolance.com for providing this sample.  These controllers gave me the ability to complete my noise testing in complete silence (my test PSU clicks very loud when switching) Thanks!!


The controller housing notes the range of use is 7.5V to 12.7V out at 25W max.  This is really ideal for the PMP-400 or similar fixed pump.


The unit is compact in size and could be installed in a variety of locations.  It comes with a piece of velcro as one option and also a pair of screws where you could solidly mount the face by drilling three holes (one for the control knob and two for the mounting screws).

It is just over 3″ long and about 1-3/4″ wide and just under 1″ tall.


Input is a 4 pin molex, output is a 3 pin header


The control knob is located up front and has a small phillips slot


I figured the most common use of the controller would be controlling a DDC pump such as the Koolance PMP-400 pump, so that’s what I used to test the controller.  I wanted to see what the actual voltage range was when feeding it exactly 12.0V while under load of the pump.  I also wanted to take a look at the pump performance and rpm to see what changed under this control.

Minimum Voltage As Measured to pump = 7.90V

Maximum voltage as measured to pump = 13.28V

Overall, this is a good range of voltage control for this pump with the exception of the maximum being a touch high.  I have found that the PMP-400 pump doesn’t like to start beyond 13.0V, so you will need to be careful to dial down the controller just a bit to ensure starting.  12.8V is about the maximum overvolting that I would consider, so that’s what I used in testing the pump.

I did my normal pump testing to measure dynamic head pressure (outlet – inlet) while increasing restriction and measuring flow rate as shown above.  I also adjusted the pump voltage via the Koolance CTR-SPD10 to several fixed voltage ranges to see how the performance is impacted.

Performance Pressure vs. Flow Rate Summary, up to a 15% pressure head increase

Here is a look at the RPM or speed of the pump for noise reduction.

Speed (RPM) comparison, up to a 35% RPM reduction


This is a great little pump controller particularly for the many pumps which are fixed in speed such as the PMP-400 or other DDC pumps.  This controller essentially gives you variable power and noise control over a pump that is otherwise fixed.  In addition it gives you the option of over-volting the pump due to it’s unique transformer.  While there are many fan controllers that could also reduce speed, this is the only option I know of that can go down to 8V and UP to 13V.  Most fan controller will have a maximum below 12.0V because of losses within the fan controller.


  • 25 watts capacity is ideal for the PMP-400
  • Over-volt (13Volts) capability can increase pump pressure head by up to 15%
  • Under-volt (8 Volts) capability can reduce pump noise for ultra silence
  • Compact size make is fairly easy to install in a variety of locations
  • Simple operation up and down


  • Maximum volts can exceed pump startup limit (user needs to reduce slightly from maximum)
  • All manual control only

Overall I am very happy with this controller, particularly for it’s unique ability to not only provide a solid 12V which most fan controllers can’t do, but also to increase it for an extra bump in performance.  I would suggest installing extra cooling on pumps that you are considering overvolting, as any sort of voltage increase will also increase heat output of the pump.

Where to Buy



  1. […] CTR-SPD10 Controller Review Detailed review Summary Conclusion This is a great little pump controller particularly for the many […]

  2. Tobola says:

    I have one question, namely: It is possible to turn off (0.0 V) this controller ?

    • Martinm210 says:

      No, roughly 7.9 to 8.0V is the lowest I could measure. This is a good thing on a Laing pump so you can’t accidentally turn it too low or bump it too low on accident, but no you can’t turn the pump off using the controller for filling a system etc. You have to unplug the power connector to get 0 volts.