my diy pv set-up

[Daox]

Do you think that your inverter is the bottleneck in the system?

[jwxr7]

Originally Posted by Daox

Do you think that your inverter is the bottleneck in the system?

It would seem to be the case on cool sunny days, but all other conditions lean toward the panels not make enough juice. It's really a pretty good match, I don't think the panels push the inverter to the max on a regular basis.

[jwxr7]

changed the array angle to the fall position saturday. I was supposed to do it in late august . Been having some dreary days lately and getting cold kinda early too. September production totaled only 23.93 kwhrs, or about 798 whrs per day.

[Xringer]

Originally Posted by jwxr7

For now I rigged up a Kill A Watt energy meter to read one side of the 240v ac line that the inverter uses. I should be able to multiply the watt hour readings by 2 to get a good idea of what the system is producing. A note on the Kill A Watt; it reads the current on the neutral line. Trying to do what I am, that is a problem. The 240 system to the inverter doesn't use the neutral for current carrying, just communication. I had to route one of the hot wires thru the Kill A Watt's neutral side and the neutral thru the other. The Kill A Watt doesn't seem to mind, and seems to be reporting current consistant to my clamp on meter.

So, if I wanted to see how much power my 230V heat pump was using,
I could cut one of the 230 lines and run it through the Neutral pins of my Kill-a-Watt?
And tie the Hot (smaller) pin to ground?
And, of course I would multiply the watts etc by two..

I'm just picturing a 120v extension cord, cut in half, plugged into the KillaWatt and patched into a 230v line..



Well, that was easy. I just took a look at the PCB and found a Resistance loop wire in between the neutral In and Out.
There is a trace on both ends of the Loop wire that lead up the PCB.
So, it seems like it might be pretty easy to wire my P4460 up to measure wattage on a 230 line.. Just need an old extension cord..

[jwxr7]

Originally Posted by Xringer

So, if I wanted to see how much power my 230V heat pump was using,
I could cut one of the 230 lines and run it through the Neutral pins of my Kill-a-Watt?
And tie the Hot (smaller) pin to ground?
And, of course I would multiply the watts etc by two..

I'm just picturing a 120v extension cord, cut in half, plugged into the KillaWatt and patched into a 230v line..



Well, that was easy. I just took a look at the PCB and found a Resistance loop wire in between the neutral In and Out.
There is a trace on both ends of the Loop wire that lead up the PCB.
So, it seems like it might be pretty easy to wire my P4460 up to measure wattage on a 230 line.. Just need an old extension cord..

It seems like that should work (my house's neutral is tied to ground in the breaker box), and there isn't any real pretty way of doing it. I ended up using the male end of an extension cord (to be plugged into the front of the killawatt) which ran out of a box with an outlet on the same box, wired specially for the killawatt to plug into. All the 230v splices are contained in the box and it kinda looks like the box is plugged into it'self thru the killawatt. Supply and load go in and out of the box too, of course.

[jwxr7]

Here are some #s for October. It was the worst month so far, very gloomy and cold. The average was only around 450 watthrs/day.

[Xringer]

Originally Posted by jwxr7

It seems like that should work (my house's neutral is tied to ground in the breaker box), and there isn't any real pretty way of doing it. I ended up using the male end of an extension cord (to be plugged into the front of the killawatt) which ran out of a box with an outlet on the same box, wired specially for the killawatt to plug into. All the 230v splices are contained in the box and it kinda looks like the box is plugged into it'self thru the killawatt. Supply and load go in and out of the box too, of course.

Thanks for the verification. This old KillaWatt is my back-up plan,
in case the whole-house monitor idea doesn't work out.

Cheers,
Rich

[jwxr7]

Originally Posted by Xringer

Thanks for the verification. This old KillaWatt is my back-up plan,
in case the whole-house monitor idea doesn't work out.

Cheers,
Rich

No problem, I hope it works for you.
I've been following your heat pump thread and really like what I see. A very neat system . I have one concern; that the start up amps might exceed the killawatt's 15 amp rating. I've done it before intermittantly without it failing, but it will beep at you when it happens. It could fail if the current is alote higher than 15 amps or a little higher than 15A for a long period of time though. Your compressor is a variable speed type driven by an inverter (I think) so maybe it won't be a huge problem to start? Maybe you could use an analogue clamp on ammeter and see what it looks like while starting before you hook up the killawatt.

[Xringer]

All the motors are DC, and they seem to be doing a soft-start when they come on..

I think in-rush current might be a problem during power-up from the circuit breakers
or during a power blink.
My guess is, the 230 AC hits some diodes and then some capacitors with a little jolt..


Notice the N & L (middle right side) go right into the PCB.. The high voltage DC supply is always live. On or Off aka standby.

The Power Relay is going to stay on continuously, unless there is a problem. Overload or pressure.

Edit:
Now that I've read what I typed.. My advice is to open the breakers during any vacations..
Why leave HV DC on and the control boards running.?.

[jwxr7]

Originally Posted by Xringer

All the motors are DC, and they seem to be doing a soft-start when they come on..

I think in-rush current might be a problem during power-up from the circuit breakers
or during a power blink.
My guess is, the 230 AC hits some diodes and then some capacitors with a little jolt..


Notice the N & L (middle right side) go right into the PCB.. The high voltage DC supply is always live. On or Off aka standby.

The Power Relay is going to stay on continuously, unless there is a problem. Overload or pressure.

Edit:
Now that I've read what I typed.. My advice is to open the breakers during any vacations..
Why leave HV DC on and the control boards running.?.

Nice set-up. That's a good idea, disconnecting when gone.
Is there a schematic showing the power supply leading to the schematic you posted? Because it shows only one AC line "hot" wire going to the control circuit. Your system is connected to your house wiring with a 4 wire system right (2 hots, 1 Neutral,1 Gnd)?
I was just thinking about a problem you may encounter trying to use the killawatt this way. If your system isn't balanced, you won't be able to accurately measure system power using one hot. There could be a 120v part in the system drawing from one hot side and using the neutral as a return. If it's hard to tell from the schematic, then this could be checked with a clamp on style ammeter while the unit is operating. If both hots have the same current and the neutral has zero then it's balanced and the killawatt idea should work well. The Gnd wire shouldn't ever have any current unless there is some kind of insulation fault . Check these currents in all types of operation modes.