How to make variable speed drive and booster pump co-exist?

[dimbmw]

Hi

I currently have an SQ1152 main pump motor and an additional booster pump for Polaris 280 vacuum. They are programmed though the mechanical Intermatic T10404R dual dial timer.

I am thinking to replace the SQ1152 with the Hayward SP3400VSP variable speed pump that has it's own timer on top of the motor.

I run booster pump for about an hour within the working interval of the main pump.

As far as I understand Hayward SP3400VSP does not have any axillary outputs to control the booster pump directly or via relay. So what is the best way to do that? I could leave the booster pump on the Intermatic timer, but I think it is not a good idea unless I will use some additional protecting relay to make sure booster pump won't turn on when the Hayward SP3400VSP is not running at high speed.

Any ideas? Maybe there is some elegant way to have variable speed pump to co-exist with a boosted pump ?

Thanks!!!

 

[JasonLion]

Your best choice is a current sensing relay, setup to only provides power to the Intermatic timer controlled booster pump when the main pump us drawing power.''

The other approach is a hayward brand automation system that will allow you to control both the variable speed pump and the booster pump.

 

[dimbmw]

Your best choice is a current sensing relay, setup to only provides power to the Intermatic timer controlled booster pump when the main pump us drawing power.''

The other approach is a hayward brand automation system that will allow you to control both the variable speed pump and the booster pump.

Jason

Thank you.

Any recommendation on the flow relay?
I have 2 concerns -
1) the paddle of the flow switch like this http://www.amazon.com/Amico-Thread-Paddle-Switch-HFS-25/dp/B0094G9UXY/ is too short to reach water - I have a 2" plumbing and the PVC tee prevent the paddle to be in deepen in the water stream.
2) flow may be too low to trigger the switch (if running VS drive at low speeds)

Thanks


PS oh I just realized you meant ELECTRICAL current relay.... sorry any recommendation on the p/n ?

 

[JasonLion]

One topic that covered this with specific device selections was this topic. There are a few more topic around here somewhere with slightly different, but similar, devices.

 

[dimbmw]

For those who are interested, this is what I bought on ebay to build the current sensing circuit. Spent less than $50 combined.