Running the Ecotech EZ Variable Speed Pool Pump Motor - GFCI Breaker Issues and Resolution

I've been upgrading my pool pump system with a variable speed motor from Emerson / Nidec / US Motors - the 3HP Ecotech EZ motor. I've described installing the motor on the pump, and the upgrade of the pool piping from 1 1/2" diameter to 2" diameter for better flow and lower restriction.

Ecotech EZ Variable Speed Motor installed on the Jacuzzi Magnum 1500 Pool Pump

The night that I finished the last of the 2" piping was when I reinstalled the salt chlorination cell. Then it was time to start up the pump for first time. Power on - then 2 seconds later the GFCI breaker feeding the sub panel in the pool shack tripped, and an error message appeared on the motor's LCD screen - blocked pump. The motor has a protection feature if the impellor gets blocked - it will prevent the motor from forcing against a blockage. I reset the breaker and tried a few times to get the pump running - then realized that I had installed the motor adapter plate backwards - jamming the impellor against the seal plate. So - 11:30 at night, and I pulled the motor from the pump and flipped the adapter plate, reassembled the pump and......the GFCI breaker still trips - but I no longer have the blocked pump error message on the variable speed control panel.

Ecotech EZ Motor Control Panel

The manual for the Ecotech EZ pool pump motor very clearly states that if you want the motor protected by a GFCI breaker, the pump must be installed on a dedicated GFCI circuit, not shared with other electrical loads. This posed a problem with my electrical system - my pool shack sub panel has 6 circuits - 4 15A lighting and power outlet circuits - one of which is the pool lights, and two 2-pole 240V circuits - one for the thermopump heater and one for the pool pump. When I moved into this house 3 years ago - only the pool light circuit was protected with a GFCI breaker. So - to upgrade the protection for the most economical cost - I protected the entire sub-panel from the feed from the house panel with a 40A 2 pole 240V GFCI breaker. The implication  of the requirement to have the Ecotech motor on its own dedicated GFCI circuit was to remove the GFCI breaker from the panel feeding the sub panel, and convert all the breakers on the sub-panel to GFCI breakers - an expensive upgrade. To try to avoid all this - I tried to get the pump to work with the GFCI breaker on the house panel - but even removing all the other loads on the sub-panel was causing the feeder GFCI breaker to trip every time I tried to start the motor. 

Ecotech EZ Motor Upgrade on Jacuzzi Magnum 1500 pump - with 2" plumbing upgrade

To get the motor running - I removed the GFCI breaker from the sub-panel feed. It started and ran fine, but with no GFCI protection. When anyone went near the pool, I shut off all the breakers on the sub-panel for safety, but this wasn't practical as a permanent solution. Incidentally - I did some research on other variable speed pool pumps - such as the Pentair Intelliflo pump - and it's installation manual also requires a dedicated circuit if the pump is to be protected with a GFCI breaker. 

I had two 15A single pole GFCI breakers from the original installation, which I put back into the sub-panel. Then I purchased a single 2 pole 20A GFCI breaker for the pool pump circuit. I installed this on the sub-panel, and it worked fine. Then I installed a second 2 pole 20A GFCI breaker for the thermopump. 

The point of this whole discussion is to warn anyone considering this variable speed pump upgrade that there may be electrical implications beyond just swapping the motor. Also - it's important to state that you should have this electrical work performed by a licensed electrician - or have a licensed electrician inspect your handywork if you decide to do this yourself. You want to ensure that the electrical systems are safely installed and will protect your family and friends from an electrical fault.

One other issue that I've run into is that I had my salt chlorination cell transformer wired with my pool pump motor - but I've had to separate the circuits in order to get the GFCI breaker for the pool pump to work. Also - the pump needs to be powered on all the time - the pump timing is now controlled by the intelligent controller on the motor, and not my central pool automation system. So I've decided to control just the salt chlorination cell from my central pool automation system - I'll program it to run on a function based on the length of daylight since chlorine degradation is a function of sunlight - and run the pool pump separately using the timer on the motor controller. I still have some wiring to get this up and running - if I run into anything interesting - I may do a separate post on this.

Once I got the electrical issues sorted out, the pump has been running now for about 2 weeks. I did some testing to check the current draw on the pump at various pump flows. The control panel modifies the pump speed as percentage of flow, and not as percentage of speed changes. Since the pump runs with a single set of programming from the factory, and every pump installation will be different with its own piping head - the percentage of flow settings on the motor will only be approximate on any system. 

What's interesting about this graph is that I can run at 75% flow consuming only about half of the full speed motor current, or I can run at 60% flow consuming only about a third of the full speed current. I wish I had taken the motor current measurement of the original single speed motor on the Jacuzzi Magnum pump - this new permanent magnet motor should be much more efficient at full speed. For the past two weeks I've been running the pump 24 hours per day, at 50% speed consuming less than 1 Amp of current. At this speed the sand filter backpressure is only about 3 psi - the power savings are impressive, and the filtration is very effective - water is crystal clear and my salt cell is performing well.

Measuring power draw of the Ecotech EZ motor using the Klein CL1000 clamp meter

Another feature of the variable speed motor is to be able to fine tune the motor speed to your vacuum and vacuum hose length, to avoid cavitation of the motor. On my previous setup with the single speed motor - the motor would cavitate whenever I was vacuuming. This would cause the pump to periodically lose prime, and suction on the vacuum. In addition, whenever I was vacuuming to waste early in the season to rid the pool of dead algae, the single speed pump was always running at full speed and drawing down the water level very rapidly. Now I can vacuum to waste at 40% flow - greatly reduce the loss of water and increase the time that I have to vacuum more effectively. I also expect that I'll be able to tune the motor to the barracuda automatic vacuum for peak performance, without using the bypass valve. 

Ecotech EZ Motor - Timer Controller is mounted directly on the motor housing

So - with the exception of the surprise expense on the GFCI breaker upgrade on my sub-panel - I'm very satisfied with this pump motor upgrade. My pump running at 50% flow is very quiet - I can't hear the motor at all outside the pool shack, and my neighbor's pool pump makes more noise now than my own. One other thing that I like a lot about this upgrade is the performance of the Jandy multiport valves - much easier to actuate by hand, nice clean looking installation. This is a positive upgrade - and I hope to see the results on my electricity bill at the end of the summer.