PSX-240 installation

elesaver

I have had a psx-240 for a while but am just now installing it.  The instructions, while simple, are not clear to me.  Of course my first thought is that if I don't understand, maybe I shouldn't be doing this.  But, just as quickly, more thoughts come which say of course I can learn to do this! 

So, here are some things that I would appreciate having some clarification.  I currently have a 24V system with an outback VFX3524 inverter.  This is an off-grid set up in essence as I have a separate panel (not a sub-panel) that contains the circuits that are active with the solar power.  Other circuits remain on the grid in the original main distribution panel.  I can choose what runs on solar or grid, etc.  and place those breakers into the appropriately powered distribution panel.  With help from this board, I have gotten everything working wonderfully well.  So, it's time to do more! 

Here's how I am thinking.  Since the batteries are sending DC to the inverter which sends 120 VAC to the distribution panel in order to obtain 240AC to the panel, I need to wire this PSX-240 into the mix.  It, then, will go between the inverter and the distribution panel so it must be on the entire time?  I do no intend to use the transformer much...I want to use it for the hot water heater from time to time.

In looking at the "installation manual" that came with the transformer, I can see the wiring from the 120 VAC source (inverter) coming into the transformer, but it appears that the 240 VAC out is accomplished by a pigtail on the hot wire into the transformer and a separate wire out from the same 25A circuit breaker within the transformer.  The two legs added together give the 240 VAC. 

If this is the case, I would have 2 wires going to the distribution panel.  Currently, in the distribution panel, I have two wires from the inverter...hot and neutral...one going to the circuit breaker to energize the panel and one going to the neutral busbar.   This diagram looks as though I need to attach  both of the 120 VAC wires to the main circuit breaker in the panel to have each of those center tabs on the panel with 120 VAC each.  When I put in the double tab breaker, then I'll have 240.

Do not be alarmed at my ignorance.  I've lived this way for a long time.    Any help on this would be greatly appreciated.

mike95490

All i can say for a project of that scope, is read the manual and look at the diagrams. 
 Beware of getting the inverter/transformer wired into the Grid inadvertently, it will instantly become apparent something is badly wrong.

elesaver

Thanks for trying to help, Mike.  This is an off-the -grid system so there is no danger of wiring to the grid.  Surprisingly, I have read, looked, studied, contemplated, searched...every verb to choose and it still is not clear. 

The separate electric panel for the solar currently has the inverter hot (black) wired to the main circuit  cut off breaker and the neutral (red) to the neutral bus bar.  I thought I would just need to wire the inverter to the psx-240 using the black and red wires from the mini-disconnect, then run wires from the transformer to the panel.  BUT, I'll need to have the two legs (red and black) now attached to the main cut off breaker to have 240 VAC.  The neutral to the busbar is what I can't seem to figure out unless you run a third wire from the transformer neutral bus bar to the panel neutral bus bar.

Anybody with help for a poor soul?

elesaver

By the way, Mike, the photo attached to your response is a hoot!  The goal is to keep that from happening!

KeithWHare

Elesaver,

Before you wire anything, you need to decide whether you are using the transformer to power a 240 volt panel from a 120 volt inverter, or if you are using the transformer to power a 240 volt load from a 120 volt breaker.

This is a picture of transformer connected to a 120 volt breaker driving a pump with 240 volts.

The black wire in the bottom right comes from the breaker. In the panel, the black wire is also connected to one of the 240 volt legs to the pump. The red wire is connected to the other 240 volt leg to the pump. The neutral is connected to the neutral bus bar in the panel.

In this picture:

• black to neutral is 120 volts
• red to neutral is 120 volts
• black to red is 240 volts
  

Since this is being used only to drive the pump. it only needs to be on when the pump is needed.

I don't know now your panel is currently wired.

I also do not know if your system has sufficient power for a hot water heater heating element.

Keith

mike95490

This is why my note of caution:

Other circuits remain on the grid in the original main distribution panel.

This sure sounds like you have Grid and Inverter power in the same room, hopefully on different panels.
The photo is from an arc flash training session.  A dummy was the model for a human. the Arc Flash is real. When it happens, the person usually perishes instantly, the unlucky linger for a few days.  don't want you to be in the photo.

elesaver

Thanks, Keith.

A picture IS worth a thousand words.  I see the white neutral running the transformer ac neutral busbar with the red and black wires.  This was my main conundrum.

The plan is to wire the transformer into the panel that is solar powered.  The breaker for the hot water heater will be put into that panel.  During the greatest sun of the afternoon, I want to use a timer to turn on the hot water for a 1 1/2 hours and only on sunny days.  So, if I only need the 240 for the hot water breaker, I could wire only that one breaker?  That makes more sense, actually, but I do not understand how to do that.  The current breaker (now located in the main panel) has the wiring coming from the water heater and then the breaker is attached to the panel.  If I want to move that breaker over to the solar powered panel,  how would I wire that breaker for the transformer wires AND the water heater wires to all be in that circuit breaker? 

Whether I have the power in this system for the hot water is yet to be seen.  With my current loads, the cc goes to float before 2 pm so that's why I figure that I'm wasting opportunity to harvest more.  I'm in the SE so we have a lot of good sun on most days, even in the winter.

Yes, the grid power panel  and the inverter power panel are in the same room but entirely separate.  I would not have considered that having them in the same room would be a danger.  Transfer switches, then, would not be safe.  At least, that was my thinking.  Obviously, I am not an electrician so I need to learn from those who are.  And, I'm with you on not wanting to be the person in the picture that you posted!

Thanks again for taking time to help, Keith.

elesaver

One more thing, Keith.  In looking at the picture again, I do not see the chasis ground wire.  I was planning to ground this to my earth ground.  Do I need to ground or not?

elesaver

elesaver said:

One more thing, Keith.  In looking at the picture again, I do not see the chasis ground wire.  I was planning to ground this to my earth ground.  Do I need to ground or not?

Actually, I do see the ground wire but I am unable to see where it is connected.  Thanks again.

BB.

Just to be clear--The photo in Mike's earlier post, I think, is a screen shot of an actual accident. Many folks have been badly burned or killed from such events.

-Bill

KeithWHare

Elesaver,

The chassis ground is connected to a lug in the bottom right corner, just above the read wire.

Is the electrical panel that is powered by the inverter currently wired as 120 volts or as 240 volts?

How do you expect to power the water heater when you don't have sufficient solar?

Keith

elesaver

OK, the drawing board has been "re-opened" for this project.  I was badly mistaken.  The
water heater now in use draws too many watts for my current set up after all.  So, there's
no point to worry with this transformer right now.  I will put it back on the shelf until another
time. 

Keith, thank you for the lessons.  None of your effort was wasted.  Once again, this board
has been absolutely wonderful...and patient.  Thanks to all.

new2PV

Another option use a dc element in the water heater with a lower wattage, avoid all your AC losses. FYI the psx-240 has an internal loss of 6 watts per winding so a total of 12 watts during the idle mode.