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Need inverter that meets my systems requirements
#11
(03-18-2020, 01:12 AM)OffGridInTheCity Wrote: I tried SSR twice with no luck (they would switch on but not off) and finally settled on "Baomain JQX-62F-2C Coil Voltage DC 12V 80A DPDT Electronmagnetic Relay"    https://www.amazon.com/gp/product/B010L02RUO/ref=ppx_yo_dt_b_search_asin_title?ie=UTF8&psc=1  which I have direct experience will work at 45a level.   

However...
1)  Look at the last half of this recent thread discussing various relays - https://secondlifestorage.com/showthread...ight=relay   
and 
2) I outgrew the 45a relay as I'm up in 48v@250amp range now...   so I switched over to wiring into the inverter's on/off switch and bypassing the power leads.   This is typically a simple circuit close/open - e.g. trivial voltage / amps - and I think almost every inverter will have an on/off switch.

TMI - in AIMS case, they have an RJ45 jack for 'external control' and its really simple - short wires 3-5 for 'Rocker switch position on' or wires 5-7 for 'Rock switch power save on'.
Why would the ssr not switch off when the battery reaches disconnect voltage, and switch on-reconnect when battery reaches reconnect voltage?

After reading that recent thread I am now more confused.. trying to figure out if a relay is for ac or dc so I don’t fry the contacts... I was under the impression that if I wanted to use an ssr for dc then I should derate the volts, like if it said 600vac then it would only handle like 150vdc, apparently I was wrong.

Offgrid are u saying I can use a relay on a wire from the inverters on/off switch so a high current-voltage from battery doesn’t need to be switched? if so could that not do damage to inverter switching off its power when it’s under high load? If it will not cause damage then how do I wire up the simple circuit closed/open as u described it?

Also u were saying about shorting 5 and 7 etc on an aims inverter thru the RJ45 jack.. how’s this done?, and is that safe to do under load?

Will the contactor u shared from amazon safely handle 64v 45amps?
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#12
>Why would the ssr not switch off when the battery reaches disconnect voltage, and switch on-reconnect  when battery reaches reconnect voltage?
Don't know why they fail...   maybe because it was DC rather than AC or it was 'fake' -  they just didn't work for me.  I tried 2 different ones Smile


>After reading that recent thread I am now more confused.. trying to figure out if a relay is for ac or dc so I don’t fry the contacts... 
>Will the contactor from Amazon u shared from amazon safely handle 64v 45amps?
Yes - its confusing.   That's why I offered an example of one (above rated for 80a contactors) that worked for me over hundreds of on/off at the 45a level.  
I also found a 48vc coil and 400a DC contactor GIGIVAC relay (GV200FA-1)  - https://www.gigavac.com/sites/default/fi.../gv200.pdf 
Here's a 150a version on ebay - https://www.ebay.com/itm/Gigavac-MX11FA-...7504!US!-1

>Offgrid are u saying I can use a relay on a wire from the inverters on/off switch so a high current-voltage from battery doesn’t need to be switched? 
Absolutely.     Here's a pic of a common/very-cheap Reliable to illustrate.  Notice the rocker switch (on/off) in the picture?  You simply take the cover off and run a pair of wires to the studs of the switch so when the relay makes contact its the same as closing the switch.        
 

>Also u were saying about shorting 5 and 7 etc on an aims inverter thru the RJ45 jack.. how’s this done?, 
I do 3 and 5 as this is full power mode.   5 and 7 is power saver mode which doesn't work for me.    3-5 are 1 position of the rocker switch and 5-7 are the other position.   It really is 'just a simple switch' wiring wise - nothing special. 


>and is that safe to do under load? 
When an inverter is off there can't be a load because the inverter is not producing any power.   When its on and you turn it off - each particular inverter will likely behave a bit differently but in AIMS case the power 'rapidly' drains away.  You'll have to experiment for your situation.

In my specific case - the inverter output is connected to the generator side of automatic transfer switches (ATS).   So when the inverter comes on - the ATS will delay the generator power (once it senses it) switch-over by about 20secs - giving plenty of time for the inverter to fire up 100%.    Once the inverter goes off - the ATS senses loss of power and switches back to grid automatically.    Here's an example of a good 30a @ 120v ATS...     https://www.amazon.com/Go-Power-TS-30-Au...221&sr=8-3
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#13
Very useful info for a rookie like myself.. thx a lot ken!

If I end up getting an inverter that is not aims, which relay would u recommend for switching the rocker switch on/off ?

Could u plz draw me up a simple (not simple for me) wiring diagram that includes the rocker switch, relay and 12v coming from charge controller.


I’m thinking about getting an aims, but 64v is max for the inverter. My battery gets to 64v. Would that be a problem?

So for the RJ45 ,,, I would just use 2 of the contacts of the relay for wires 3 and 5 of the RJ45 chord and the other 2 contacts of the relay are the trigger positive and negative coming from the charge controllers auxiliary
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#14
(03-19-2020, 01:02 AM)Doin it Wrote: Very useful info for a rookie like myself.. thx a lot ken!

If I end up getting an inverter that is not aims, which relay would u recommend for switching the rocker switch on/off ?

Could u plz draw me up a simple (not simple for me) wiring diagram that includes the rocker switch, relay and 12v coming from charge controller.


I’m thinking about getting an aims, but 64v is max for the inverter. My battery gets to 64v. Would that be a problem?

So for the RJ45 ,,,  I would just use 2 of the contacts of the relay for wires 3 and 5 of the RJ45 chord and the other 2 contacts of the relay are the trigger positive and negative coming from the charge controllers auxiliary
IF you had a Midnite Classic Controller, you could use the Aux1 on/off switch directly to turn the inverter on/off.   The yellow is the midnite software interface where I've set inverter off at 49.5v and inverter on at 53v.


The Midnite Classic has an option for Aux1 to send 12v when on and 0v when off (instead of just being a switch).  So here's the same thing as above except we're using a relay with a 12v coil.   This arrangement (using a relay) would let you do + and - power leads to the inverter as long as the contact can support the level of amps.


>I’m thinking about getting an aims, but 64v is max for the inverter. My battery gets to 64v. Would that be a problem?
The AIMS docs say 64v will trigger a high voltage alarm...  so 64v would work but it might be a touch too hi - you could try it.  If it was a touch to high why don't you simply lower the battery charge max to 63v?         I'm sure your charge controller let's you configure the the absorb/float values...  so just configure them to be slighly below 64v.

>which relay would u recommend for switching the rocker switch on/off ?
Any / cheap relay with at least normally open contact as there is no amperage involved - its like a small transistor radio on/off switch - milli-amps at best.   You just need to match the coil voltage to whatever is turning the relay on/off.    If that were a Midnite Classic - it would be 12vdc.   
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#15
Yes I could lower voltage of battery bank to 63v but I would prefer to keep the battery capacity I have.. it’s 6kw battery bank and I’m only getting 3kw (is this normal?) out of it with gridtie inverters set to shutoff at 58.5 and on at 64v.

Option 2 using a relay, if the inverter doesn’t have the RJ45 jack then I would connect to the rocker switch contacts instead?

Above u said that
“as long as the contact can support the level of amps”
but u also said
“Any/cheap relay with at least normally open contact as there is no amperage involved”
Do I have to be concerned with amperage in wires that connect to inverters rocker switch contacts if I wasn’t using an aims?
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#16
(03-19-2020, 04:42 PM)Doin it Wrote: Yes I could lower voltage of battery bank to 63v but I would prefer to keep the battery capacity I have.. it’s 6kw battery bank and I’m only getting 3kw (is this normal?) out of it with gridtie inverters set to shutoff at 58.5 and on at 64v. 
 Earlier you stated "...using 64v (16s ev pack)...".   A 16s lithium-ion would be 16*4.2 = 67.2v ...   is this what you have?  / need more detail to answer these questions.   

Howeiver, as an example, Lithium ion based  64v/16 = 4.00v/cell  vs 63.5v/16 = 3.97v/cell - trivial amount of power 'lost' if you pull back from 64v hi to 63.5v hi.


(03-19-2020, 04:42 PM)Doin it Wrote:   Option 2 using a relay, if the inverter doesn’t have the RJ45 jack then I would connect to the rocker switch contacts instead? 
Yes.


(03-19-2020, 04:42 PM)Doin it Wrote: Do I have to be concerned with amperage in wires that connect to inverters rocker switch contacts if I wasn’t using an aims?
Not likely - it should be < 1a        A small rocker switch does not carry an amperage,
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#17
I do have a 16s 67.2v lithium pack, but only charge the pack to 64v, isn’t it best to not charge them to max? I thought charging to only 4v a cell was recommended. Or maybe that’s only recommended for used lithium-ion cells, which is what I have, but was only supposed to only have 18000 miles on the car..

I could get more out off the batteries.. drain them down to the minimum they recommend 56v (3.5v per cell) which is way below the knee, and charge up to 65.6v (4.1v per cell), would be a lot closer to 3kw per battery then... kinda scared to do that tho.. using the 58.6v to 64v charge parameters the cells have stayed perfectly in balance (less than .1v difference,, I’m about to get a bat-go (or something similar) to keep track of the cells and balance a little.. Maybe then I’ll expand the charge parameters.. wow I just realized that’s 4.2v of battery voltage I could be using,,, i suppose that’s where the rest of the capacity is..

If I use an aims as u recommended I could lower the batteries high charge to 63.5v (instead of 64v) and lower the bottom to 58.1v (instead of 58.6v) and still have same capacity I’m using now
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#18
I see - 16s lithium-ion.   I hate to see you 'give up' the ability to charge up to 4.1v/cell etc inverter wise.   Take a look at Magnum - https://www.solar-electric.com/lib/wind-...manual.pdf  (seems like a very solid main stream brand).  They have 48v @ 4000watts and you can double up to get 48v@8000watts if you want.

See page 51 - it shows 
HBCO (Hi Battery Cut Out) of > 67.6v ...   67.6/16 = 4.225, so it would let you use 100% of your battery.
LBCO (Low Battery Cut Out) down to 40v (adjustable).

My personal recommendation would be to go with something like this - that gives you full options.   

For example, my design is geared for XX kwh (on average) out of my battery bank - this is needed to balance PV input vs load so I don't loose any PV power.   I do this on average in the range of 3.9v/cell hi and 3.54v/cell low.    As my battery degrades, I will need to increase the range to maintain the same XX kwh.   I plan to go all the way to 4.15v near the end-of-life of the battery to use it all up!      So in your case, I would suggest that (as you originally posted) you find  equipment that gives you the full range of options.

The other track - of using relay to control inverter on/off is still valid.
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#19
(03-20-2020, 04:46 PM)OffGridInTheCity Wrote: I see - 16s lithium-ion.   I hate to see you 'give up' the ability to charge up to 4.1v/cell etc inverter wise.   Take a look at Magnum - https://www.solar-electric.com/lib/wind-...manual.pdf  (seems like a very solid main stream brand).  They have 48v @ 4000watts and you can double up to get 48v@8000watts if you want.

See page 51 - it shows 
HBCO (Hi Battery Cut Out) of > 67.6v ...   67.6/16 = 4.225, so it would let you use 100% of your battery.
LBCO (Low Battery Cut Out) down to 40v (adjustable).

My personal recommendation would be to go with something like this - that gives you full options.   

For example, my design is geared for XX kwh (on average) out of my battery bank - this is needed to balance PV input vs load so I don't loose any PV power.   I do this on average in the range of 3.9v/cell hi and 3.54v/cell low.    As my battery degrades, I will need to increase the range to maintain the same XX kwh.   I plan to go all the way to 4.15v near the end-of-life of the battery to use it all up!      So in your case, I would suggest that (as you originally posted) you find  equipment that gives you the full range of options.

The other track - of using relay to control inverter on/off is still valid.
If I was going to use my system as offgrid everyday I could see buying a magnum or similar inverter. I’m only going to use it if there’s a power outage or if shit hits the fan. That being said I really should be getting more out of my battery, so since the aims (800$ for the 2000 watter) wont allow me to use my batteries at 65.6v. I think I’m going to keep looking for a comparably priced inverter that will take 65.6v..
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#20
FYI - I looked up SMA Sunny and Outback (other main-stream inverters) and the 48v FXR model has 68vdc max input.   In the relm inverters that I've seen in a lot in posts and youtubes....
- Reliable, AIMS, MPPSolar, SMA Sunny are to low.
- Magnum and Outback look promising.

I'll be interested to read what you decide Smile
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