Lancie1,
Thanks for your help.
I had also read that the PC-to-Smart Relay transfer would wipe out the program. And you are correct that I am reluctant to do this without a copy of the program in hand in case my home-brew version would somehow fail to work.
Question: If you had known the PLC was password-protected, and one reason you stated for purchasing it was because it had this PLC, then would you have even bought this pump model at all?
I would have probably went ahead and bought this unit anyway. The application, in case I hadn't mentioned it before, is for a residential swimming pool filter pump. I was in the middle of installing a pool automation system (Hayward/GoldLine AquaLogic - I got such a good deal on it that I could not build one from scratch any less expensively). While I was transferring circuits from the old mechanical timers to the new system, I was switching the upstream 30 Amp circuit breaker on and off quite a few times. One of these times, the two-pole 240 volt breaker malfunctioned and only gave my 240 Volt filter pump a measly 120 Volts. The filter pump motor did not like this, got really hot, and croaked. I was going to replace this 2 HP filter pump next spring anyway, so it just meant that I had to do this job a little sooner than expected.
The residential swimming pool market is going to change radically for 2008 in California. Historically, residential pool pumps have been powered by oversized (2 HP pumps instead of 1/2 or 3/4 HP) single-phase motors. Ignoring the lousy efficiency of single-phase motors in general, these oversized pool pumps create very large dynamic head losses because of the unnecessary friction in the piping and pipe fittings. As of January 1, 2008, the State of California is banning the sale or purchase of single-speed pumps for use in swimming pools, and, at a minimum, is requiring the use of two-speed motors. The theory is that the normal high speed of 3450 rpm will be used only for initial priming and perhaps for spa jets if the pool has an attached spa. The rest of the time the pump will be running at low speed at 1750 rpm for filtration purposes. The idea is that an equivalent amount of water will be run through the filter, but it will take longer and use less overall electricity.
I didn't really lilke the idea of two-speed pumps because of the inherent limitations. So I wanted to go with a variable speed solution. As of this writing, I know of only two vendors who offer variable speed pool pumps. One is Ikeric Systems
www.ikeric.com which is the one I went with. This unit uses a three-phase motor, which is inherently more efficient than single-phase motors, along with a plain vanilla Square D Altivar 11 variable speed drive. The three-phase motor is attached to the filter pump and the vsd is in a separate panel. Tried and true technology, but just being applied to the residential pool market over the last 3 or 4 years. Plus I was going to be able to play with the PLC that was also in the panel.
The other vendor offering variable speed pool pumps is Pentair Water Pool and Spa and their IntelliFlo pump. Now this one is a horse of a different color. This one uses a brushless DC motor (or as Pentair refers to it - a permanent magnet synchronous motor) with the drive directly attached to the motor. During my research, it appears that brushless DC motors are more efficient than three-phase motors, and especially so when relatively unloaded (10% - 50%) when three-phase motor efficiency falls off the cliff. This system would have been $200-$300 more expensive and easier to install (no separate panel to install). I could have easily justified the extra money due to the higher efficiency and cleaner installation, but I got scared when I could not find what a replacement brushless DC motor was going to cost if it failed after the warranty was up, whereas three-phase motors are as common as sand on the beach.
http://www.pentairpool.com/products/products3.php?id=76
Hayward Pool Products is bringing out a plain vanilla variable speed drive in a separate panel which powers a plain vanilla three-phase motor. It appears to be very similar to the Ikeric Systems product, but it will not be out on the market until early 2008. Does anyone recognize the brand of PLC that Hayward is using in the attached link?
http://www.haywardnet.com/pdfs/TriStarEnergySolution_LITTSESB07.pdf
Sorry for rambling. Hopefully the above will be useful for those with swimming pools. And this stuff is really important for those of us in California. Having a pool usually pushes one into the upper tiers of power cost, which for PG&E is on mind-numbingly high order of 32 cents per kilowatt-hour.
So saving energy with these kind of pool pumps can really save a ton of money.
Titanium
