Harvey1958

ArnSpa: I'm up in Pleasanton and do indeed have two sons still in the home. I watch my hourly stats through the PGE website and can see quite clearly when our family wakes up, does laundry and cooks just from the usage. We get cold enough weather to freeze the dog water bowls and annoy the jade plants too. But we don't have the thermal mass that you do of course in our tub. I agree though, it would take more than evening to freeze it up. I have a Gazebo overhead with 2x2's on two inch centers that I want to center some black 1/2" irrigation tubing on and then drive a DC pump on a 85W solar cell to push the spa water through. The backpressure from the tubing and all the elbows is considerable so the pump needs to be big enough to produce enough head to get to the roof and then push the water through, but I'm convinced it would make a difference. I have about twice the surface area up there as I do on the tub which on some sites seems to be the right rule of thumb. I work for Solar Millennium, so when you work all day on what will be the worlds largest solar thermal project (1000MW Parabolic Mirror) laying black pipe on a gazebo roof seems like a good project. I'll run some tests on the three wire circuit this weekend and will see and share what might work. Hoping PGE will come out this week for the final approval on my roof system. Harvey

Hi Spa Savant, thanks for your input. I hadn't thought about simply dropping out the entire pool during the peak hours. It's clear if I drop out the controls/filter pump/ozone system, obviously the heater would drop out as well. It's not as clear cut since it's a three wire output from the 30 Amp breaker and I need to research how to incorporate the Intermatic switch into a three wire circuit. How do you set the timer for the winter months to avoid freeze damage, and to keep the tub warm enough for use when you want it? I have a good cover, but my Caldera Tahitian is only 360 gallons so we have much less water to heat up. My comment on the $.40/kWh was more around picking out what I thought the blended rate would end up being depending on where I was in the tier. This is the rate sheet you are on as well, correct?: http://www.pge.com/tariffs/tm2/pdf/ELEC_SCHEDS_E-6.pdf Thanks again for your insight. Harvey

So Watkins Mfg. came back and would not disclose which leg controls the heater, said they will not support any modification to the wiring, and no, they don't have a control panel or mod that will position the operating hours of the tub to coincide with time of use metering. They did confirm that summer setting will indeed drop the tub totally out for 8 hours following initiation of summer settings, and summer settings can be initiated at temperatures higher than min settings. That will indeed help since my $.40/kWh time period is from 1PM through 7PM through Oct 31. I left message with and followed up with the Berkeley based Caldera shop, and received no reply from their tech. I'm hoping to get confirmation back from this esteemed forum in the meantime. Thanks, Harvey

Hi Folks, I have a Caldera Tahitian hot tub that has a sub panel with two breakers; one is a 30 AMP GFCI three wire system, which when tripped, kills all the controls to the tub. The other breaker is a 20 AMP, two wire GFCI that I am hoping goes only to the heater circuit. Tub is on 240VAC. I recently installed a 4KW solar system on my home and will be switching over to a Time Of Use payment billing rate with PGE to maximize the rate I get for producing solar. This also means that I get charged $.40/kWh for power I use during the summer months between 1 PM and 7PM. I absolutely want to minimize my consumption during those times and I don't ever want the tub to kick in to heating mode between the hours of 1PM and 7PM or I pay $.40/kWh. I found an Intermatic T104R timer that is a Double Pole Single Throw (DPST) switch capable handling 40 AMP resistive load at 120-480VAC. The instructions and diagrams for the switch are here: http://www.intermatic.com/~/media/files/intermatic/products/instructions/timers/t104%20-%20english.ashx more details are here: http://www.intermatic.com/products/timers/mechanical%20time%20switches/24%20hour%20dial.aspx Would you be so kind as to confirm, that the two wire, 20 AMP circuit goes just to the heater and this is where this switch could be installed by a licensed electrician? The tub does have a summer mode setting which shuts the tub down each day for eight hours from when you activate it. But it also requires putting the temp down to 80 F. If anyone knows how to reprogram this to allow a setting of 104 degrees F, with a summer shutdown setting that would work even better. Thanks, Harvey