Case study: Variable speed on Jandy RS

Yesterday I had a chance to install a variable speed pump on a pool that is controlled by a Jandy RS system. Now, this was an older system that uses the 52 pin board and was, therefore, not compatible with Jandy’s variable speed pump. While some of Jandy’s e-pumps come with an upgrade chip for the RS control system, the chip will not fit in a 52 pin board – it only fits in boards made within the last year or two. Thus, if I were to use Jandy’s e-pump, I would have to upgrade the board. This was too expensive.
Instead, I chose to use a Pentair Intelliflo VS3050. This is the pump that used to be called the Intelliflo 4 x 160. The VS in the name indicates Variable Speed (as opposed to their other pump that is variable flow). The 4 stood for 4 speeds and the 160 stood for the max gpm.
To use the VS3050 with the Jandy RS system I had to used Intellicom II. This is a major advance over the first generation Intellicom. This is a small cell phone size adapter that converts the 24 v relay outputs of the Jandy system to RS485 communication protocol that selects the pump speed.
The Pentair reps will tell you that the Intellicom requires the use of a separate auxiliary per speed. This isn’t quite true, and if you did it that way, it would be complicated for the customer to use.
Here is how I setup my install. I set the following speeds on the pump. (I set the speeds before connecting the controller):
Speed 1: I set this to a speed fast enough to operate the suction pool vacuum.  Pressing the “Filter Pump” button on the Jandy activates this speed.
Speed 2: A super low speed for filtration, This is just fast enough to break the plane of the water with the skimmer wier. The “Low Speed” button on the Jandy activates this speed. (Turn on dip switch 2 to set “Aux 2” to “Low Speed.”) This is the only extra auxiliary that is necessary to use that is not used with a single speed pump.
Speed 3: A speed suited for the 400,000 BTU heater --somewhere close to 40 gpm. This is higher than the low speed setting. Imagine what would happen if the heater was turned on when the “Low Speed” was selected. The pressure switch would be marginal and the heater would not have the minimum flow that the heater required. To avoid this, I used the “Electric Heater” relay output on the top of the Jandy board near the actuator outputs to activate Speed 3. The Logic of the Intellicom is such that it always selects the higher of the speed number if more than one is selected. In other words, if both speed 2 (low speed) and speed 3 (heater speed) are selected, it will run at speed 3.  This protects the heater. It is also fool proof. The customer can’t select the wrong speed.
Speed 4: This is a high speed for the spa jets. It is really cool how I activate this speed. I used the “spare aux” relay output located on the back of the RS control board. To get this relay output to activate when the spa is turned on, set dip switch 6 to “on". (This does not work on Rev. G or earlier chips--you must upgrade those chips to take advantage of this feature.) This way, any time the spa is switched on, the pump automatically goes to speed 4. The customer doesn’t have to do anything different. They just press the spa button as usual and the jets come on high.
Two good things about this installation:

1. First is saves energy. The customer should save around $900 per year.
2. Second, it is no more complicated for the customer than would be a two-speed pump. While the pump itself has more speeds and is more adjustable, all the complexity is kept in the background. It is very simple for the user.