Jandy variable speed motor retrofitting - now with curves

mas985

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If the VRV is located at the top of the panels and the return plumbing has not fully primed, then the VRV will likely remain open, leak air into the pipes and air will continuously come out of the returns. It would be unusual to have a closed VRV without fully priming the pipes for this scenario.

However, if the VRV is lower than the top of the panels, it could still remain closed and the return pipe is not fully primed. One way to check is to increase RPM after the panels have been running for a while and no air out of the returns. If air comes out of the returns after increasing RPM, the plumbing was not fully primed. This is not a critical situation but may create a bit more noise in the plumbing as water is falling down the return pipe rather than flowing down so pipes tend to rattle.

At a minimum, the panels need to prime or you will lose efficiency. This is usually not an issue if the panels are sloped so that air can travel upwards. If on a flat roof, the panels would most likely purge all of the air if there is sufficient flow. One easy way to check is to use an IR thermometer to check that all panels are the same temp. Plus if you target a flow rate of 0.1 GPM/sqft, then you can almost guarantee the panels will be primed.

Of course if the speed is too low, water may not reach the top of the panels and the flow would just stop but you would know that as no water would come out of the returns which I think happens in a couple of your tests.
 
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MSchutzer

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Ben,

Your flow rates for the solar off case seem a bit high compared to what I am seeing. We both have 1.65 HP impellers and here are my flow rates and filter pressures for my system with the solar off. My filter pressures are close to yours so I would assume the system TDH is similar.

Speed. Filter Pressure. Measured Flow Rate
3450. 11 psi. 85 gpm
3100. 9.2 psi. 75 gpm
2850. 7.9 psi. 68 gpm
2600. 6.5 psi. 60 gpm
2350. 5.5 psi. 55 gpm
2100. 4.4 psi. 50 gpm
1850. 3.3 psi. 42 gpm

I have a Flo-Vis flow meter in between the pump and filter so I am able to directly measure the flow rates under various conditions.

Given the flow numbers that I measured with similar filter pressures at the various speeds it seems like your flow rate estimates are a bit high.

I hope this helps,

Mark
 
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BenB

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Thank you, Mark! That's super clear and I really appreciate the extra detail. Since the flow rates are all far higher than the minimum recommended just as a byproduct of RPM, and since they're sloped, I think in my case I'm safe regardless of placement. But the explanation was still super helpful.
 

BenB

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Jul 24, 2020
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Mark #2 swooping in as well with the assist! :)

Thanks for those numbers - that's really helpful and aligns my expectations a little bit. We all say that 'turnover doesn't matter' so in a sense they're theoretical, but good to know what might be more realistic, confirm my question that it sounded high compared to what i feel, and also in terms of what i can extrapolate for the solar per panel... You wouldn't happen to have those written down too though would you to save me some maths? :)

The nerd in me is curious whether maybe there's a significant difference between the Jandy Stealth wet end performance and the Whisperflo, or whether the Stealth curve that I started with was faulty, or.... something else. But at some point I have to let these things go and just go for a swim in the pool rather than theorize about every aspect of it! :cheers:
 
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MSchutzer

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Ben,

For the solar on case I only have measurements for the speed that I’m running, 2600 rpm. At 2600 rpm my filter pressure is 11.5 psi and the flow rate is 48 to 50 gpm. I have seven 40sq ft copper panels so that’s about 7 gpm per panel which is a bit higher that the 4 gpm that the manufacturer tested with, but if I drop the speed to 2350 rpm the 42 to 43 gpm doesn’t quite keep the vacuum breaker closed all the way and I get air bubbles in the returns.

At 2600 rpm you have 13 psi Filter pressure so it’s still pretty close to my system pressure so I would guess you are moving about 45 gpm at that speed.

Mark
 
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BenB

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Jul 24, 2020
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Today's update. Put the old 2 speed motor (2.6THP 2-speed) and matching wet end into the sheer descent pump to replace its original single speed 2.2THP motor. Hard wired it to run on low speed only.

I was worried as it was priming that I'd have just a dribble, but then magic! It just about works well enough for my needs. The water doesn't shoot out very far from the wall (maybe 1 foot at the waterline), but it works, is quieter than it used to be (both water noise and pump), and is pretty which is the main purpose.

Overall a huge success. Effectively upgraded 2 pumps from 1 motor purchase.

Celebrating by reducing my TA - dropped the pH to 7 (1 whole gallon of MA!) and using them to aerate the water :)
 

BenB

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Jul 24, 2020
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@MSchutzer sorry to bother you. I'm curious how you wired up the digital units to the motor, when the aux outputs of the controller are DC but the solar JVA is AC? It occurred to me if I wire them up together the solar line would send AC back up to the aux which would be bad! Also which of the 3 pins did you pick up for the switching?

Thanks as always!
 

MSchutzer

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Ben,

I just used the Jandy relay contacts for all my connections. The aux outputs drive the relays and then the relay is just a contact closure. There’s also an extra aux (in addition to the 3 wire JVA connector) output labeled solar that can connected to a relay. I plugged a relay into that connection and used it’s contacts to select the solar speed. This solar aux output activates under the same conditions as the JVA output so that the motor speed changes as the solar activates.

You just need to mind the priority of the digital inputs on the Vgreen as the higher number input has higher priority over the lower numbered input. So you want the slower filter speed 1 to be programmed to input 1 and your faster solar speed (speed 2) programmed to input 2. The fltr/pump relay output runs the duration that your want to run your pump, and then the solar speed will trigger input 2 when you want the pump to run faster. The priority of the input assures that you get the faster speed when both inputs are closed at the same time.

You can extend this to three or four speeds as long as you recognize the priorI ties of the inputs.

I used the pump’s own +12v power (pin 1 of the RS-485 connector) as the voltage source for the digital inputs. I connected ground from the RS-485 connector (pin 4) to the ground connection on the digital input connector. Then I routed the +12v connection through each Aqualink relay contact and back to the digital inputs. There’s a schematic showing this connection in the Vgreen manual.

If you don’t want to use the Aqualink relays you can in theory connect directly to the 2 pin aux terminals but note that those are all 24 vac driving the relay coils. The Vgreen can take 24 vac directly on its inputs, you just have to make sure that you use the same “common” connection off of each aux output. Pick either the left or right pin of the connector and call that common and stick with it.

Edit: The above paragraph talking about the Aqualink relays having 24 vac coils is incorrect, they are actually 24 vdc. The Vgreen will also accept 24vdc on the digital inputs so it supports direct connection to Aux or Solar Aux outputs. Sorry for the confusion.

I already had enough relays so I just used them as it isolated everything.

I hope this helps,

Mark
 
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BenB

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Jul 24, 2020
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San Jose, CA
Thanks, Mark.

I first tried the direct connection method at the weekend but mixing AC/DC was causing issues. The DC output from the aux worked exactly as it should, as did the AC switch for the solar, but when connecting both at the same time even when only the aux was activated the DC would somehow make a voltage appear on the AC side too which would then flow back to the pump end and end up activating Step 3.

Next I tried a separate relay unit in the manner you describe (sending 12V DC back from the pump to be switched by the relay to try and keep the automation's power isolated), but that did...something that blew the fuse (24VAC) on the Jandy board altogether upon first use as the JVA got about halfway through its turn. So I'm now waiting until a box of 10 fuses comes from Amazon tomorrow to try again - I don't want to be without the controller altogether!

What Jandy relays are you using? The only ones I can see are either the full-size (often described as '3HP pump relay') or the smaller one for switching a 2-speed pump. But both of those are ordinarily triggered by the 24vDC aux outputs, so I don't think would work? Are you taking a tap of your solar switch (3-pin) directly to one of those? I have one of each open right now that I could potentially use, but it's only really the AC one causing issues!

Thanks again.
 

MSchutzer

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Ben,

You shouldn’t have to deal with the AC for the JVA actuator at all. There is an auxiliary output labeled slr-pmp (solar pump) right next to the solar JVA connector that is 24 vdc and meant to connect to one of the Jandy 3 hp relays.

I’m using the relays because I have them, but you should be able to connect that slr-pump aux directly to the Vgreen and it will be DC like all the RS’s Aux outputs. Here’s a picture of that connector.

That output only goes active when the solar is active (when solar is enabled and solar temp sensor is 5 degrees above the water temp). It turns On and off at the same time the JVA changes positions.

Mark
0CCC7381-FA1F-4381-8764-59B8E6490C01.jpeg
 
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BenB

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Jul 24, 2020
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💡💡💡💡💡💡💡

Oh my goodness that's incredible. You've just saved me hours more pain dealing with the AC side! I'll just hook into that and as you say be done in no time.

I'm equal parts relieved to have it sorted and frustrated that had I realized this from the very beginning (I guess I thought there was such a thing as a Solar Pump and not that label simply indicating a solar signal to the pump or a booster pump), I could have wrapped this up over a week ago and saved me $$ in unnecessary relay and blown fuse purchases!!

Will report back when the deed is done.
 

BenB

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Jul 24, 2020
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San Jose, CA
Nothing is ever simple :)

It turns out that on my Jandy board at least, the +24V is always live, and the aux switches close the COM (0V) leg to complete the circuit. That is to say, the pin that has continuity between all the aux outs is the signal voltage line. Therefore when we look at the pump end, the pump will either see -24VDC (as I need to reverse the polarity to keep the signal voltages separate), or it will always see a voltage on the highest input regardless of which aux was activated, because that's the common. And it seems the V-Green is not responsive to the -24VDC signal.

So I will have to use a simple relay network after all. Sadly the one I used the other day (cheap from Amazon) blew up on first use (seems like it was a common issue based on the reviews) so waiting another couple of days until a replacement arrives. But at least I can use a DC relay instead of the AC/DC relay which seemed more rare. I'll spare the fancy Jandy ones for another use and also that will keep low voltage and high voltage fully separated in the cabinet.
 
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MSchutzer

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Ben,

Actually switching the low side to activate the auxiliary outputs makes a lot of sense from the circuit design point of view. Low side switches (N channel FETs) have lower on resistance and cost less than an equivalent resistance high side switch (P channel FET’s).

It‘s also a lot easier to directly interface the low voltage digital signal pins to a N channel FET.

Since those outputs normally drive relay coils it doesn’t matter which side gets switched, but it is a bummer that you can’t directly interface to the Vgreen.

Looks like you need a couple 24 vdc relays.

Mark
 
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BenB

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Jul 24, 2020
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San Jose, CA
I'm going to lose my tiny little mind....

The SLR-PMP output reads 24V on a multimeter, but as soon as I connect that output across an actual load - even just a relay - the voltage drops to 2V and therefore fails to switch the relay. Swapped the relays and cables, it follows the output.

At this point I'm tempted to place a home warranty call on the whole board.

The actual hard part of swapping the pump took me about 2 hours, this quick connection exercise is taking forever!!
 
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MSchutzer

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Ben,

I assume your solar system was active when you were checking? Solar needs to be enabled and active (jva valve In the solar position) before that output goes active.

Mark
 

BenB

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Jul 24, 2020
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Yes indeed. Although / also, in service mode the buttons override the temperature logic. I can measure 24v with solar enabled and cable unplugged, then as soon as I hook it up to the relay it drops. Voltage measures good until both legs are placed across a circuit. Problem follows the output only - if connected to a regular aux connector it works perfectly.

Thanks for always jumping in with your thoughts and advice. I really appreciate it.
 

mas985

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What is the relay amp rating for the coil? There is probably a limit on the current for those drivers. Usually less than an amp. If you draw too much current, you can fry the driver.
 

BenB

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Jul 24, 2020
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Coil says it activates at 5mA. Same relay works on other outputs, so yeah probably dead. Board looks ok but I guess it didn't have to die dramatically.

I placed a service call, hopefully they'll agree to swap out the PCB.