Basic VFX3024E setup - help needed

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Basic VFX3024E setup - help needed

Postby roks on Thu Aug 10, 2017 12:17 am

Hi All,

After sitting in storage for many years I have finaly setup the vfx for basic backup system in Bangladesh. I just need some re-assurance from your experties that its working as it should.

Its a very basic with just a mate for power outages, times can vary between 30mins to several hours occationally. Its powering several energy saving lights (20watts each) and 5 sealing fans (~60watts each).

I am at a loss trying to get the battery details from the manufacturer (one of the best in the country apparently) and the local dealers are clueless. I have 2x200Ah 'tall tubular' wet charged batteries, both measured 12.73-12.75v out of the box. Can I assume the battery is fully charged and its at 100% SOC? Because when I turned system charge current dropped to 1amp.

I set the charger AC current to 3.0Amps, settings below: v
Absorb: 29.2v
Time: 4:0hrs
Float: 27.0v
Time: 2:0hrs
refloat: 25.0v
Time 2:0hrs

Is thais OK for this setup?

What should the battery voltage be after the charge is complete? I am seeing 26.4v and declining slowly. When the inverter is operating, voltage dropped as low as 24.6v (drawing ~21A dc) before the mains supply was restored after about 30mins.

Also, when I first connected the batteries it was absorbing at 0.5A AC for 2 days while I was offsite, it was set at 29.6v and 4hrs. when I came to site it was still charging, I dont know if that was charging continuosly or the re-float kicked in.
Could I have damaged the battaries?

Also, I noticed that after finishing the absorb cycle, the voltage drops (to ~25.5v) below the float setpoint 27v but the float does not kick in. Is that normal?

Does everything appear set correctly?
Attachments
Untitled.jpg
VFX3024E
Mate
Battery 200Ah 24v
Mains AC for charging
roks
Member
 
Posts: 12
Joined: Sat May 15, 2010 3:56 am

Re: Basic VFX3024E setup - help needed

Postby Mike Curran on Thu Aug 10, 2017 9:37 am

Hi Roks- I'll take a shot at this, I'm sure others will chime in. Note lots of IMO's :grin:
roks wrote:I am at a loss trying to get the battery details from the manufacturer (one of the best in the country apparently) and the local dealers are clueless. I have 2x200Ah 'tall tubular' wet charged batteries, both measured 12.73-12.75v out of the box. Can I assume the battery is fully charged and its at 100% SOC? Because when I turned system charge current dropped to 1amp.


Best way to check state of charge (SOC) is by measuring the specific gravity of each battery's electrolyte with a hydrometer. Having said that, those out of the box voltages are closer to fully charged than to any possibly worrisome state of discharge, IMO. However, I would think you would be charging at a higher rate during absorb unless batteries are either (a) already at or near fully charged (most probable, IMO), or (b) new batteries are already sulfated (not likely, IMO).

roks wrote:I set the charger AC current to 3.0Amps, settings below: v
Absorb: 29.2v
Time: 4:0hrs
Float: 27.0v
Time: 2:0hrs
refloat: 25.0v
Time 2:0hrs

Is this OK for this setup?


Those look like good starting points, again IMO.

roks wrote:What should the battery voltage be after the charge is complete? I am seeing 26.4v and declining slowly. When the inverter is operating, voltage dropped as low as 24.6v (drawing ~21A dc) before the mains supply was restored after about 30mins.


I have my own system set up to float at 26.4v temp compensated, so 26.4 shouldn't be anything to worry about, but you should see it closer to your float setpoint of 27v immediately after absorb stage is complete, for your 2 hour float time setting, if grid is still connected. The slow decline you're seeing is normal for a battery under load but without grid support, or with grid but float time has ended.

roks wrote:Also, when I first connected the batteries it was absorbing at 0.5A AC for 2 days while I was offsite, it was set at 29.6v and 4hrs. when I came to site it was still charging, I dont know if that was charging continuosly or the re-float kicked in.
Could I have damaged the battaries?


If you had an intermittent grid connection whereby system went on and off battery power multiple times, it's very possible refloat, or even rebulk (fixed setting of 24.0v for VFX inverters, IIRC) kicked in. Don't know how reliable your grid supply is there but if you lost it long enough your system voltage and battery SOC could've decayed to suboptimal levels (say, 21v, 50% SOC) but over 2 days' time with new batteries I don't think it's likely they're damaged. 0.5A AC at 220V equates to about 5A DC charging current, about 2.5% of your battery rating. That COULD be the proper end amps you'd expect from the absorb stage on your batteries.

roks wrote:Also, I noticed that after finishing the absorb cycle, the voltage drops (to ~25.5v) below the float setpoint 27v but the float does not kick in. Is that normal?


If you still have grid power following the absorb cycle your system should go into float mode, maintaining system voltage at 27.0v for your preset float time of 2 hours. So seems like something's not right there.

I'm looking at the manual for my GVFX's for above info, hopefully I've interpreted it correctly and it applies for your VFX.

- Mike

PS I've done several edits on this, please forgive for any confusion I may have caused.
Mike Curran
OutBack Guru
 
Posts: 195
Joined: Sat Aug 28, 2004 6:28 pm
Location: Chagrin Falls, Ohio
My RE system: Outback: 8 (2x4) Evergreen 180's into one MX60, 6 (2×3) ALEO S79-300's into one FM80, 2 grid-tied GVFX3524's classic stacked for 120/240VAC, 12 Surrette/Rolls 2V x 1766Ah, Hub10.3, Mate3, FNDC, RTS, OpticsRE. Tigo Energy ES maximizers on each PV module.

Westinghouse Solar: 30 (2x15) 235W panels with Enphase M215 microinverters. 6,450 nameplate watts AC, grid-tied.

Re: Basic VFX3024E setup - help needed

Postby roks on Thu Aug 10, 2017 12:45 pm

Thanks for your reply Mike, its answered some of the doubts.

The fins looked clean when I removed the caps of the batteries, did a quick test, sg 1250 on the meter. There was a greenish line going across the length of the battery, like a marker pen.

The 3amp AC for the charger is pushiung out ~23.5A DC (measured the -ve battery cable with clamp meter) so thats about 11% of the battery bank capacity. Do you think I can increase that a little more without affecting the battery life?

Yes, the charger kicks into absorb after a power failure and once complete it goes into silent mode while the voltage trickles down to 25.5v and does not go into float (yes grid is available). Although I did notice the mate showing float once but dont know what triggered it.

I did notice the mate is a bit sticky as in when I go into the meter, it does not refresh the status, Ill have to click through couple of menu and go back then it would display the headings.

There appears to be a 2.0A DC being drained from the battery and also the mate shows "input current" as 2A AC. This while it showed 'silent' in the mate. Is this normal?

What can I changw to minimise the drain on the battery?
VFX3024E
Mate
Battery 200Ah 24v
Mains AC for charging
roks
Member
 
Posts: 12
Joined: Sat May 15, 2010 3:56 am

Re: Basic VFX3024E setup - help needed

Postby Mike Curran on Thu Aug 10, 2017 5:03 pm

Rolls Battery recommends 20% of the battery C20 rate for maximum charge rate, which is 40A for you. They do say "Higher current levels may cause the battery bank to overheat. A lower current may be used, however this will prolong charge time (during the bulk stage)." It'd be nice if you could find specs on your battery...sounds like you've already tried.

The manual for your inverter (http://www.outbackpower.com/downloads/d ... manual.pdf)
says it goes into silent mode after the bulk/absorb stages are complete, so I was mistaken about that :^o : "The first SILENT mode follows ABSORB. During this time, the FX charging operation stops, but continues monitoring the battery voltage." So it won't go into float until it reaches the refloat voltage. Sounds like that's what yours is doing so no worries there.

My guess is the 2.0A DC current draw you're seeing is from whatever loads you have connected. That's only around 48 watts, might just be your inverter draw in silent mode (does seem kinda high, though). Anything else running? But, 2.0A AC doesn't really correlate (220V×2.0A=440 watts) - maybe the discrepancy is due to rounding in the current measurements, plus efficiency losses in your inverter. At this point I'm REALLY hoping somebody more knowledgeable than me speaks up!

Silent mode just means the inverter isn't charging (as described in quote above). It's waiting for voltage to decay to the refloat point.

- Mike

PS SG at 12.50 is at the low end of fully charged, Rolls says 100% charge range for SG is 1.255 to 1.275 so you probably should be charging longer in absorb stage.
Mike Curran
OutBack Guru
 
Posts: 195
Joined: Sat Aug 28, 2004 6:28 pm
Location: Chagrin Falls, Ohio
My RE system: Outback: 8 (2x4) Evergreen 180's into one MX60, 6 (2×3) ALEO S79-300's into one FM80, 2 grid-tied GVFX3524's classic stacked for 120/240VAC, 12 Surrette/Rolls 2V x 1766Ah, Hub10.3, Mate3, FNDC, RTS, OpticsRE. Tigo Energy ES maximizers on each PV module.

Westinghouse Solar: 30 (2x15) 235W panels with Enphase M215 microinverters. 6,450 nameplate watts AC, grid-tied.

Re: Basic VFX3024E setup - help needed

Postby blackswan555 on Thu Aug 10, 2017 9:37 pm

As above but to add,
Its powering several energy saving lights (20watts each) and 5 sealing fans (~60watts each).
Be careful with reading Watts, Inverters work in KVA like generators, A compact floro lamp that says 20w on the side can actually use 40 VA, Fans are not so bad but still wattage is no use, If you want to find out, look at label, take voltage stated and multiply it by amps stated, That is how much it uses "in our language"

Tim
My comments are based on my experience and research, They are not endorsed or checked by Outback.I am an independent British electrician living in Spain, So please take this into account when reading /acting on my post`s.
blackswan555
OutBack Emperor
 
Posts: 2445
Joined: Sat Aug 30, 2008 5:50 am
Location: Ibiza Spain,
My RE system: Other peoples, VFX "E" versions, FLA`s, Generators.


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