Ecotech EZ Variable Speed Pool Pump Motor Upgrade - Jacuzzi Magnum Pump

I've been working towards the goal of reducing my electricity bill by 33% - and I'm actually getting there. One of the largest loads besides heating and ventilation at my house is the pool pump. I have a typical single speed 1.5 HP Jacuzzi Magnum pool pump for an 18' x 36" rectangular in-ground pool. I like to open the pool early and close it late, and the kids love to swim. My estimates for running the Jacuzzi Magnum pump was around $500 / pool season full time. I've been running the pump on a time, for about 12 hours / day - so I guess I've actually been consuming around $300 per year in electricity. Thankfully, my marginal electricity cost is only about $0.095/kW-hr.

Ecotech EZ Motor installed on the Jacuzzi Magnum 1500 Pool Pump. The control panel is directly on top of the motor.
Last year I did a fair amount of research on the subject. and the key to saving electricity with a pool is to take advantage of pumping affinity law - which simply means that increasing the flow by 10% costs you 33% more in power. Similarly, reducing the flow by 25% will result in energy savings of approximately 50% - due to the reduction in friction losses by reducing the speed of the water in the piping (and importantly, across your filter element).

You can do this with multi-speed pumps - which can be standard wound-rotor pumps with a two or three speed tap - which will result in some savings, or even more significantly, with a electronically commutated permanent magnet variable speed motor, which are the most efficient commercially available motors. To take advantage of this simple principle, the state of California has mandated that new pool installations have as a minimum multi-speed pumps which default to low speed operation for filtration (California Energy Commission (CEC) Title 20 Appliance Efficiency Regulations).

My pool is probably a fairly typical installation for a 20 year old pool in the Province of Quebec - all the piping is 1 1/2 inches in diameter, and I have a 1.5 HP single speed motor, with a sand filter with a 1 1/2 inch multiport valve. My thermopump was added following the original pool installation - and it would have been difficult to imagine a less efficient plumbing addition to a system - to add the Thermopump - the pipe from the sand filter to the pool was extended by about 30 feet long in total - 1 1/2" piping - in a long serpentine.

So why upgrade just the motor, and not purchase a complete new pump? Because if you already have a decent pump - the motor will end up costing about 50% of the cost of a complete pump. If you're a bit handy, this isn't a particularly difficult upgrade. The hardest part may be the electrical part - and if you're switching the complete pump out - you'll need to deal with that anyway. My aim going into this upgrade is that the cost for the upgrade would be paid back within 2 years, and purchasing a complete new pump would not allow me to achieve that.

Starting point - Jacuzzi Magnum Pump with Single Speed, Permanent Split Capacitor Motor
So - to take best advantage of the variable speed motor upgrade, I also planned to upgrade as much of my piping as possible to 2" diameter, and relocate my thermopump to optimize the piping arrangement. I also planned to remove and replace all my 1 1/2" ball valves with 2 inch Jandy multiport valves - to simplify the plumbing and minimize the number of bends in the piping.

The first step in the project was to split the original single speed motor from the pump, and install the Ecotech EZ motor. This isn't terribly difficult to do, and it is also an excellent opportunity to replace your pump seal. The basic steps are as follows:
  • remove the pump from your system and disconnect the power;
  • split the pump from the motor by unscrewing the clamp ring between the motor and the pump;
  • unscrew the 2 screws retaining the diffuser, and lift the diffuser off;
  • unscrew the impeller by holding the motor end of the drive shaft, and unscrewing the impellor counter clockwise; 
  • lift off the seal housing (now is the time you would replace the motor shaft seals); 
  • unbolt the motor housing bracket (four bolts)
Preparing the Motor Housing Bracket for installation on the new Ecotech Motor
Note the clamp ring installed over the motor, with the seal plate installed over the motor housing bracket and motor shaft
Installing the impeller
Installation of the new motor is the reverse of the steps above, I won't go into details, there's quite a few good videos available explaining seal replacement on all types of pool pumps. Just ensure you take very clear note of the orientation of all parts during disassembly - photos will help. And - make sure you install the clamp ring right from the start - otherwise you'll be doing all the steps twice....

The Ecotech EZ motor installed on the Jacuzzi Magnum 1500 Pump - Ready to Install on the Pool
I'll write a separate post on the piping upgrade around the pump, sand filter and thermopump, Following that, I'll post about wiring up the new pump, the electrical considerations, power draw of the new motor, and the performance of the system. It's getting a bit too late to finish everything tonight.


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