diy solar

diy solar

EG4 3000 EHV-48 fire. Been running a 12 panel system with 2 EG4-lifepower batteries and the EG4 3000 EHV-48. Added the battery rack and 3rd battery

This thread is starting to make me wonder if there are emergency shutdown contact options for the server-rack batteries... same for the PV RSD.
 
shopman said:
This was an issue of resistance. A short in the inverter caused current to flow at a controlled rate, a rate that was under the limit of the BMS and circuit breaker so the battery did its thing and provided power. This is very different from inrush current where the instantaneous demand for current can far exceed what the battery can provide, thus the BMS shutdown.
Click to expand...
According to Will's video, these batteries have a precharge resistor. Some posters have reportedly used the precharge resistor, or a workaround precharge resistor, yet the issue of starting some inverters remained. Does the precharge resistor not mitigate the inrush issue?

Yes, it is understood the 4awg wire size acted as a heater with increasing resistance as the temperature rose, but it just seems odd they can dump that much current but have issue starting some inverters. YMMV
 
ncsolarelectric said:
Absolutely! The shutdown switch must be within 5-ft of the battery.
Click to expand...
Not a manual switch, a remote interface like a fire alarm shutdown contact. If you have more than 6 batteries it makes it complicated to be compliant with code. The RSDs can usually be rigged to disengage PV remotely (interposing relay on the RSD actuator circuit), but I'm not sure of anything for server rack batteries. Of course you can shunt trip the combined system, but a bus fault would still be a problem.
 
Kornbread said:
According to Will's video, these batteries have a precharge resistor. Some posters have reportedly used the precharge resistor, or a workaround precharge resistor, yet the issue of starting some inverters remained. Does the precharge resistor not mitigate the inrush issue?

Yes, it is understood the 4awg wire size acted as a heater with increasing resistance as the temperature rose, but it just seems odd they can dump that much current but have issue starting some inverters. YMMV
Click to expand...

But the use of the pre-charge resistor is only at start-up? ...Which leads me to the (newbie) question, how to size the pre-charge resistor?
 
Shimmy said:
Of course you can shunt trip the combined system, but a bus fault would still be a problem.
Click to expand...

A "keep alive" rather than "shutdown" signal would be fail-safe.
My furnace has several over-temperature sensors. If any opens due to excessive heat, or if a wire opens, that turns the fan on.
 
chess-equality said:
But the use of the pre-charge resistor is only at start-up? ...Which leads me to the (newbie) question, how to size the pre-charge resistor?
Click to expand...

If zero DC load until inverter is enabled, resistor could be arbitrarily high resistance and low wattage; just wait for a long RC delay and voltage coming up.
If DC load is present, resistance has to be low enough and wattage high enough to power it.
If inverter powers up automatically after some short delay from application of power, resistance must be low enough and wattage high enough to precharge whatever capacitors before inverter starts operating. And switch shorting out bypassing resistor closed before then.

In other words, "it depends".
 
Hedges said:
If zero DC load until inverter is enabled, resistor could be arbitrarily high resistance and low wattage; just wait for a long RC delay and voltage coming up.
Click to expand...

Watching Will's videos, I only use one during startup (white ceramic).

But I've been eyeing something like this one below, has some big ratings (up to 1k Ohms) and looks much bigger than the one I'm using ?

Ceramic Tubular Adjustable Resistor Rheostat 10w 20w 25w 30w 5/10/20/30/50/100/150/200/500/1k Ohm | Lazada PH

Type : Hand tool parts.
www.lazada.com.ph www.lazada.com.ph

 
Put a DMM on inverter side, connect your precharge resistor, note how long for voltage to come up.
After it stabilizes, measure voltage across resistor, see how close to 100% of battery it came. Calculate current draw.

Precharge is only difficult if inverter starts drawing high current automatically.
 
Many thanks to Signature Solar for jumping on this and replacing the defective EG4 3000 EHV 48! Great company to deal with! And yes, I am adding more breakers and switches for safety, lowering the voltage by putting more panels in parallel and adding a second Inverter/controller
 
Endsofearth said:
Many thanks to Signature Solar for jumping on this and replacing the defective EG4 3000 EHV 48! Great company to deal with! And yes, I am adding more breakers and switches for safety, lowering the voltage by putting more panels in parallel and adding a second Inverter/controller
Click to expand...
That’s good to hear. I only have half my string up and think I’ll run the in parallel just in case as I don’t have any fire suppression system set up yet. May be something worth looking in to now as I have two of these 3000s and expect to buy two more.
 
dianea said:
The problem may be resistance of poor terminations at the end, which become hot spots and "fuse" out the circuit. My EG4-LL does pretty good and can even warm up 2awg cables at 100amps. I checked everything at maximum load with a thermal camera to be sure no hot spots or bad connections could create fires later. This is usually done every year at large facilities, so we don't have property damage or downtime due to fires.
Click to expand...
Any recommendations for a good thermal Camera?
 
carefulmistake said:
That’s good to hear. I only have half my string up and think I’ll run the in parallel just in case as I don’t have any fire suppression system set up yet. May be something worth looking in to now as I have two of these 3000s and expect to buy two more.
Click to expand...
I may take one of my 5# co2 units and set it up on an automatic sprinkler head, will also double 5/8" drywall the electrical room and put in a fire door that seals plus an alarm system. We are in the middle of nowhere and don't want to burn down the mountain.
 
koppted said:
Any recommendations for a good thermal Camera?
Click to expand...
Stick with Flir.
I have tested three Chinese models so far ranging from $250-$650 and they all seem to be using the same sensor which is a Flir knock off.
On paper the resolution is excellent but in reality they all have dynamic range issues.
I have a Flir One Pro for the iPhone and it has the best dynamic range and clearest image of all of the four units.
They have more expensive Flir Units like the E4 and C5 that have built in screens and cost $700 and up.
For Solar and electrical work you really do not need to spend that kind of money.
 
robby said:
Stick with Flir.
I have tested three Chinese models so far ranging from $250-$650 and they all seem to be using the same sensor which is a Flir knock off.
On paper the resolution is excellent but in reality they all have dynamic range issues.
I have a Flir One Pro for the iPhone and it has the best dynamic range and clearest image of all of the four units.
They have more expensive Flir Units like the E4 and C5 that have built in screens and cost $700 and up.
For Solar and electrical work you really do not need to spend that kind of money.
Click to expand...
I have an older 30+ years Minolta Dimage digital camera and on candlelight setting with an infrared filter it works great, just don't take pictures of people with that setting. 1.1MM lens for 11" close up work and I used it a lot on motor bearings
 
robby said:
Stick with Flir.
I have tested three Chinese models so far ranging from $250-$650 and they all seem to be using the same sensor which is a Flir knock off.
On paper the resolution is excellent but in reality they all have dynamic range issues.
I have a Flir One Pro for the iPhone and it has the best dynamic range and clearest image of all of the four units.
They have more expensive Flir Units like the E4 and C5 that have built in screens and cost $700 and up.
For Solar and electrical work you really do not need to spend that kind of money.
Click to expand...
Hey thanks, I looked up Flir thermal imaging on Amazon and i'm seeing anywhere from $300 to $700. Is there something more affordable around? Going in I was thinking maybe $80 at the most, these seems crazy to me. I'm assuming from your previous post that anything in that $80 price point would be no good?
 
Last edited:
Your not going to find anything for $80.
You can try eBay for something used for around $180 and some no name Chinese brands in that price range. Keep in mind if it’s not reporting a fairly accurate temp readings then it’s not all that useful.
 
Endsofearth said:
I have an older 30+ years Minolta Dimage digital camera and on candlelight setting with an infrared filter it works great, just don't take pictures of people with that setting. 1.1MM lens for 11" close up work and I used it a lot on motor bearings
Click to expand...
Take some long exposure shots of the night sky, you might be surprised at what you can see with the IR filter removed.
 
koppted said:
Hey thanks, I looked up Flir thermal imaging on Amazon and i'm seeing anywhere from $300 to $700. Is there something more affordable around? Going in I was thinking maybe $80 at the most, these seems crazy to me. I'm assuming from your previous post that anything in that $80 price point would be no good?
Click to expand...
The Flir units go on sale often but you’re still looking at $150-180 range for the android and iOS versions.
 
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