Any thoughts about water cooled tube for transformer, instead of wire?

[solarnewbee]

The words moist and electronics together made me cringe. Cool dry air is always best. Try hunting thru thrift stores, flea markets Ebay etc for the smallest dehumidifier you can find. Refrigeration and HVAC is just one of my expertises. Dehumidifiers are just low btu air conditioners. The could build some flexible duct to the evaporator side to the fan intake. Be sure to duct the heat side outdoors or your defeating the whole process. The fact that the moisture is condensing on the evaporator means that heat is being drawn away and air is cooled. Normally btu In cancels btu out just allowing for moisture removal. This is why you want duct the condenser coil heat outside.

[MadScientist267]

The big thing with water is that while it may start out non conductive, the moment it makes any kind of contact with any metal (and really much of anything that can dissolve in it), it becomes conductive. This is why it's not used.

[sunnypower46]

My first thought re using a dehumidifier was that they aren't really designed to put out cold air, just remove moisture from the air.

To cool the torroid, I need cool air and a lot of airflow (235 cfm).  While an interesting idea, modifying a small dehumidifier to get me there seems like it would fall short.  Maybe a 5000 BTU room AC appropriately modified to direct the air where needed could do it, but the penalty is probably 700-800 watts from the inverter output.
 
I'm thinking if I keep the relative humidity off an evaporative pad under 60%, I'll be OK.  I believe the PJ is good to at least 85% RH.  Summer in the SoCal inland areas sees humidity in the 15-20% range.  It's pretty easy to get a 15-20 degree F temp drop by misting a cooler pad. 

When the outside air and garage gets to 105F, I'd be happy to put 90 degree F air into the inverter located therein for a few hours.  Obviously, I don't want water droplets getting into the inverter.  And I haven't run any numbers to see what temperature drop correlates with a 40% increase in humidity off the pad.  My goal may not be achievable.

Regarding the torroid in distilled water, I hadn't considered that reacting with metal might change its non-conducting properties.  If we adequately encapsulate the torroid and attached wires somehow, I guess it really doesn't matter.  I drop a small submersible AC outlet plug-in pump into my pool spa when it needs to be emptied.  Haven't blown any breakers or tripped a GFI yet.  Given the moving parts, that would seem an even greater isolation challenge.  Yet they manage to get UL certification.

[DBCollen]

they are usually double sealed and oil filled

[solarnewbee]

My pj is in a room with a window set at 30c and the fan on constantly. Earlier this week I had my daughter’s boyfriend add the 5v6 zener for battery level and a cheat for the ct to allow higher wattage. This added nearly another 1kw to just below 4 kw and it hasn’t shut down due to toroid overheating.

Of course I have helped my daughter to design a schedule to manage use wisely since I’m 10,000 miles away.

My 15kw has 24v fans and they scream and push a lot of air. One was a regular 3wire computer fan for the toroid but I slid that next to the toroid and put a 24v from Amazon in place. Maybe all you need is simply get a fan that’s the same voltage as your battery bank. An example would be:   

https://www.amazon.com/gp/aw/d/B077GJNMYP/ref=ppx_yo_mob_b_inactive_ship_o0_img?ie=UTF8&psc=1
It’s 185 cfm and I assure you when I put another one in my 8kw our housemaid quit sleeping in there.

I love to experiment and have bells and whistles but sometimes the k.i.s.s. System is best also.

If your experimenting great, but please don’t tempt fate with water.

[sunnypower46]

I really don't need to make any changes to my PJs at this point.  They do OK in the heat of summer because my microinverters cover the heavy daytime loads.  I've got enough extra microinverter output to push back 80A (2000+ charging watts) through the PJ that's mostly dedicated to battery charging.  That drops off linearly over a three hour period in the morning before it gets too hot outside. 

My Morningstar dump load controller manages FLA battery charging.  Does a great job keeping the battery voltage below the PJ's upper limit.  Haven't needed the Zener diode mod.

A further attempt at extra cooling would merely be to extend equipment lifespan/reliability.  Whether the cost to benefit ratio is favorable is certainly in doubt and I don't underestimate the value of keeping things simple.  Often it's best to just let things be.  Is there anyone who hasn't learned that lesson the hard way?

I don't need anything close to 4000w from my PJ; but if you've got the battery juice and enhanced cooling, I think 4000w continuous is achievable - - for anyone following this discussion who might have the need.

[solarnewbee]

Hey Sunny,

Very well said. Hope you didn’t feel I was harsh. The whole thread got my brain thinking of ways to experiment. When I go back to the Philippines I’m bringing a monster pj that I’ve managed to make much more efficient. So the 8kw will be there to play with. I have spare coils boards and mosfets.

I often think about micro inverters and charging. My 15kw is minus the charging board but the 8kw has charging. I ended up with 5.3kw in panels. After spending 5grand on lfp’s not sure if it’s cost effective to spend that money. I would need iq7plus and the envoy with software. Then there’s the landscape wire right? Grounding, no ground there so install a grounding rod that I never can seem to get to.

Well it’s a thought.

[sunnypower46]

Somebody correct me if I'm wrong, but when using any PJ for back charging batteries from micros; no internal charging circuit is needed or used. 

Just connect the total micro output to the PJ output and the micros send the power through your PJ to the battery bank or to your loads.  If included on your PJ model, never make any connection to the charging input connections.  The micros go to the PJ output to provide the "local grid" which turns the micros on.  In this mode, nothing in the PJ prevents overcharging your batteries; however.  You have to do that externally via a dump load controller.

I've been using IQ7 plus micros for nine months.  They pair well with PJs.  You don't need the Envoy monitoring to make the system work.  It's all pretty plug and play.  Just make sure the micros you buy are preset for your country's power. 

[solarnewbee]

I see what you’re saying. My 15kw has a board inside that’s labeled charging board and the board is not present where it would plug up in other models. Control boards are a complete re-engineer. My 8kw says off grid and I never bothered trying to tie to the grid. I have a ATS that switches to grid when the pj drops out. The pj has a plug for charging but I didn’t see any need for it. I thought if I switched to micros that I would us a 24v 80a intelligent charger or build a a larger one at a higher voltage and current and feed that thru one of the mppt chargers. My current issue is that out of 5.3kw of panels the charge controllers are showing at high noon only around 3.6 to 3.9kw between the two sets. They are set 3 in series for 108v 300w each 3 sets paralleled front roof same on back roof east west orientation. One controller always shows more kw than the other. PV voltage will be the same at noon but the kw will be high on one low on the other. Bad connection? The installer connected more sets on one than the other?

Would micros take all this guess work out of it? As long as I can charge a full tank and run the house?

Hmmm?

[sunnypower46]

If you want to try micros with your current setup, maybe this approach:  Take one group of three series panels out of the parallel configuration.  That should allow your current system to work OK at reduced output while you experiment. 

Then wire up one (or three) micros to the panel(s) and connect to your PJ8000-24(?) OUTPUT.  Fire up the PJ and five minutes later the micros will start producing power.  This solar power has to go somewhere, either into the attached loads on the PJ or back through the PJ into your battery bank.  It's magic.  The micro power output just goes where it needs to go.  But, you do need external hardware to protect the batteries from overcharging as part of the total system design.  For short periods under supervision, you could test the system without the extras.

If you want more expertise on how to do this, I'd suggest starting a new subject so more in the community can weigh in.  We're getting off track on the OPs original subject.  Be sure to present the big picture of your current setup and what you ultimately want to do.