ph Dosing pump setup

[tloomos]

I'm installing a ph Dosing pump - Hanna Instruments BL-100 - and ran into a slight problem with the wiring. I'm hoping someone may be able to help so I don't have to wait for tech support on Monday.

I have a Jandy RS pool controller and I want to power the pump through a relay, and the relay will be powered by the switched side of the filter pump relay - so the ph dosing pump will only get power when the pump is running.

The power wire to the pump has 3 wires - hot, neutral and ground. I tried connecting hot to the relay (which is ultimately powered by one leg of the 220 for my pumps) and the neutral to the neutral wire from the controllers power source. It immediately tripped the GFCI due to the unbalanced load. For now I took the relay out of the mix and just have constant power to the ph pump and I'm manually controlling the ph dosing pump so its only on when the filter is on.

Any ideas how I can accomplish what I'm trying to do here?

 

[Ahultin]

I tried connecting hot to the relay (which is ultimately powered by one leg of the 220 for my pumps) and the neutral to the neutral wire from the controllers power source

If this was going to work, you would need to hook the neutral from the ph pump to the load side neutral on the gfci breaker.

That said, the manual for the bl100 says it supports input voltage from 100-240v. If that's the case, wiring for 240v would be ideal. The manual however does not show this wiring option so i would hold till Monday and confirm with Hanna tech support

 

[wireform]

Just had a similar situation at a pool with an aquarite SWCG when I found it powered after the timer shut the pump. It had been plugged into a 120v outlet which wasn't being controlled via a timer therefore the SWCG was relying on the flow switch which we know is considered here on the TFP as a secondary an a not a primary switch option. I wasn't thinking and tried hooking into the timer using one left and the neutral to the neutral block but the puff went the gfci until I realized what was happening. Then I changed the aquarite to the 240v configuration and the rest is history.

 

[tloomos]

Thank you! For now I have it connected to the 120v, but routed the hot side of the 120v through the relay so I can at least schedule it to coincide with the filter pump. I would just feel better if it didn't have any power at all if the filter pump is not running as an additional layer of safety. I'll see what they have to say on Monday about being able to connect it to 240v power.

 

[tloomos]

I just installed a Hanna Instruments BL100 ph dosing pump this weekend. I still have a couple things I want to adjust once I get some input from Hannas tech support, but it's up and running and seems to be working well. I'd like to get some feedback on my installation and anything I've done that is questionable from a safety perspective.

I have the pump wired so it only receives power if the main pump is running.

The things I'm a bit concerned about:
1) My approach to avoid direct sunlight on the controller and protect the equipment from large hail (a frequent concern in north Texas)
2) My approach for leaving the pump outside through the winter
3) My attempt at venting the acid tank

Avoiding Direct Sunlight
The manufacturer says direct sunlight will damage the controller, so I mounted it inside an enclosure. The unit is water resistant, so I wasn't concerned about having a water-tight enclosure (although the one I used started out that way). I added a couple 2" vents on the back and drilled some weep holes into the bottom of the case to allow some airflow and allow any water that does get inside to drain out. I have a temp sensor in the case so I can monitor temps to see how hot it's getting inside when the late afternoon sun shines on it.

Handling winter temps
The pump is rated down to 32 F, and the manufacturer recommends disconnecting it and bringing it inside if temps will go below that. I installed an outdoor-rated light fixture into the enclosure, put a low wattage bulb in it (currently 25W, I'll monitor how that does), wired it into my pool controller, and set it to turn on with the freeze guard. The goal is to generate enough heat to prevent it from freezing inside the box without making so much heat that I risk melting anything or starting a fire.

Venting the acid tank
The acid is stored in a 5 gallon bucket with a sealed rubber lid. I used 1/2" PVC to create a vent. At the top of the pvc, I drilled 8 holes, each around 1/4" and put a 1" PVC cap on top to prevent water from getting inside. Not sure if this is enough ventilation. So far, I haven't experienced a strong smell from the acid when I've been working over there, and if I open the large flap where I pour acid in, there isn't an overwhelming release of fumes.

 

[Ahultin]

Per Hanna tech, the power supply is auto switching so you can install it 220v off of the filter pump relay. The second hot goes to the neutral block on the bl100.

 

[laszlof]

Interesting setup. This is actually a lot cheaper than the TruDose system Jandy sells.

@tloomos What was the model number of the enclosure you have? I'd be curious if that light you have is really needed in winter time. Is there anything liquid inside the device that cant be drained out? I realize you shouldnt operate it below 32 degrees, with if its shutoff, and drained, I dont really see much of an issue just leaving it outside (enclosed) during the winter time. Particularly since its IP67 rated. That should keep moisture out of it.

 

[tloomos]

Per Hanna tech, the power supply is auto switching so you can install it 220v off of the filter pump relay. The second hot goes to the neutral block on the bl100.

Thank you! I got confirmation from Hanna this morning that this is exactly correct!

What was the model number of the enclosure you have?

The enclosure is a Gratury junction box from Amazon. It's a very solid box. I got a Numananee box to protect the power supply for my pool cleaner, and while I love the built in water resistant vents, it's definitely thinner and more "flimsy" than the Gratury box is.

I'd be curious if that light you have is really needed in winter time. Is there anything liquid inside the device that cant be drained out? I realize you shouldnt operate it below 32 degrees, with if its shutoff, and drained, I dont really see much of an issue just leaving it outside (enclosed) during the winter time. Particularly since its IP67 rated. That should keep moisture out of it.

The response I got from Hanna tech support when I asked about winter temps was "The controller cannot be exposed to temperatures below freezing or it could damage the display and affect the way it operates. The environment specifications are between 32 and 122 degrees." Through an abundance of caution (and a desire to not pull the controller inside during the winter) I tried to find a way to keep it above freezing without too much effort. I'm going to keep a close eye on it this winter to see how the temp in the box fluctuates and determine what the right size bulb is to create just enough heat to keep it above freezing. I'll pull the tubing out for the winter since it's so easy to put that back in when I open the pool in the spring.

 

[laszlof]

Thank you! I got confirmation from Hanna this morning that this is exactly correct!



The enclosure is a Gratury junction box from Amazon. It's a very solid box. I got a Numananee box to protect the power supply for my pool cleaner, and while I love the built in water resistant vents, it's definitely thinner and more "flimsy" than the Gratury box is.

Thanks! Looks like a really nice box, and a perfect fit for what you needed.

The response I got from Hanna tech support when I asked about winter temps was "The controller cannot be exposed to temperatures below freezing or it could damage the display and affect the way it operates. The environment specifications are between 32 and 122 degrees." Through an abundance of caution (and a desire to not pull the controller inside during the winter) I tried to find a way to keep it above freezing without too much effort. I'm going to keep a close eye on it this winter to see how the temp in the box fluctuates and determine what the right size bulb is to create just enough heat to keep it above freezing. I'll pull the tubing out for the winter since it's so easy to put that back in when I open the pool in the spring.

The 32 and 122 degree marks are interesting. Thats exactly the operating temperature range for LCD screens. However, storage temperature is much wider, something more like -4F to 140F.

I'd imagine the unit would be fine even in a colder climate to leave outside as long as its not powered on. Obviously you made provisions to avoid that situation, but I'd probably try to wing it and see how it worked out.

 

[tloomos]

The 32 and 122 degree marks are interesting. Thats exactly the operating temperature range for LCD screens. However, storage temperature is much wider, something more like -4F to 140F.

I'd imagine the unit would be fine even in a colder climate to leave outside as long as its not powered on. Obviously you made provisions to avoid that situation, but I'd probably try to wing it and see how it worked out.

If it turns out I don't need the heat lamp in there, my plan is to put one of the 2" vents in that hole instead - with the summer we've had here in North Texas, the high temps might be more of a concern than the lows!

 

[laszlof]

If it turns out I don't need the heat lamp in there, my plan is to put one of the 2" vents in that hole instead - with the summer we've had here in North Texas, the high temps might be more of a concern than the lows!

I saw you were in Texas and was thinking the same thing! Its been brutal down there.