navitron
 
Renewable Energy and Sustainability Forum
Welcome, Guest. Please login or register.

Login with username, password and session length
News: Anyone wishing to register as a new member on the forum is strongly recommended to use a "proper" email address - following recent spam/hack attempts on the forum, all security is set to "high", and "disposable" email addresses like Gmail, Yahoo and Hotmail tend to be viewed with suspicion, and the application rejected if there is any doubt whatsoever
 
Recent Articles: Navitron Partners With Solax to Help Create A More Sustainable Future | Navitron Calls for Increased Carbon Footprint Reduction In Light of Earth Overshoot Day | A plea from The David School - Issue 18
   Home   Help Search Login Register  
Pages: 1 2 [3] 4 5 6   Go Down
  Print  
Author Topic: Info Please on ELTEK SMPS 5000 SIL V3 48v/100A, Mains 230vac Charger  (Read 20148 times)
knighty
Hero Member
*****
Offline Offline

Posts: 2798


« Reply #30 on: April 11, 2015, 11:49:44 PM »

I think he means it has one output for under voltage, and another for over voltage

but he needs to use relays to latch them, and they pulse/flick on/off ?
Logged
clockmanFR
Hero Member
*****
Offline Offline

Posts: 3584



WWW
« Reply #31 on: April 12, 2015, 09:49:52 AM »

Yes knighty.....

Hmm......Okay, I will try and explain the 'Under & Over voltage Unit' a little better this time chaps.

When the voltage of my batteries gets down to about 49.4v the  U&OVU, the 'Under & Over Voltage Unit', recognises this low voltage and switches its single internal relay 'On'.

When the batteries voltage starts to rise, ie being charged,  at about 50.2v the U&OVU switches Off its internal relay, dddeeerrr, so using this to operate the AC Contactor is not going to work, it will end up cycling On Off. hmm.

Now say the charger was working and the batteries voltage is rising nicely, then at 54.5v the U&OVU recognizes this voltage and switches on its single relay 'On'. But wait, I want the unit to switch Off the AC Contactor controlling the Eltek battery Charger,  dddeeeerrrrr.

So I thought, and I thought, and thought of many things, but it must be simple and robust and as Jonesy said must stand some punishment.
Then I remembered Latching relays, from my youth eons ago.

So the Batteries are low at 49.4v, the U&OVU switches on, so 1 continues pulse is sent to the latching relay. The battery voltage rises, and at about 50.2v the U&OVU switches Off, so the continues pulse is removed, but the latching relay is still On as it has not received another pulse yet.
Now when the charger gets the batteries up to to say about 54.5v, the U&OVU recognises this and switches on and a pulse is sent to the latching relay and promptly switches Off the AC Contactor and the Eltek Charger.  extrahappy

A couple of things,.....
 I can set the Eltek to charge up to Float charge, why you ask? well just in case the Tristar PWM have gone to float and they would then start dumping excess voltage to my 6kW air Heaters.
Therefore the U&OVU max limit should be below the Elteks Max set rate of Charge.

If the Second pulse does not happen then the Eltek will carry on charging but only up until its max limit is reached, so nothing should be harmed.

False triggering..... The U&OVU is surprisingly good at not false triggering and there seems a delay of about 1.5 second from voltage reached and the U&OVU internal relay activating. And the voltage needs to move about 0.5v to 1.0v before the U&OVU internal relay de-activates.

As I said 'Jonesy', I really tested the U&OVU unit and Not false triggering is surprisingly Okay.
However I suspect the timer delay holds off any unwanted false triggers, and I have used that method my self with the good old CMOS 555NE chip to give just 1 clean Square edge Impulse trigger from a messy source.

As regards the Time delay 'Fionn', well when set to max of 15 seconds, crikey the Red triggering light is flickering on and off like a demented Ferret, that's on Speed from 'Biff's' Place.
 But still the first flicker is the trigger and approximately, I say approximately because it wanders a fair bit by about 5 seconds, then the internal relay clicks on.
Its unlikely that I will use the Time delay function as its just a poor quality pcb mounted ceramic wiper screwdriver adjusted Resistor. So at present this time delay is set at 0, which as I said earlier is still a 1.5 second delay.

If any of you have a better idea of monitoring the low and high voltages of my battery Bank and switching on the Eltek and
switching it off again, that's simple, robust and cost effective. I am all ears...........................

And don't forget chaps and chapes's, I could always revert to the Sunny Island switching the Eltek Charger ON & OFF,  facepalm.  But I might be gone a few days  faint trying to sort out all the parameter settings for the SI relays.
 And knowing my luck with the SI,........... "Oh gosh another Bug".    :hysteri

And by the time you have read all these jottings you have probably confirmed in your own mind, that 'ClockmanFR is very strangely odd'.
 Grin help

  
« Last Edit: April 12, 2015, 10:01:10 AM by clockmanFR » Logged

Everything is possible, just give me TIME.
clockmanFR
Hero Member
*****
Offline Offline

Posts: 3584



WWW
« Reply #32 on: April 12, 2015, 10:28:25 AM »

Jonesy....... yes, your comment, "as it can get out of sync".    A fail safe to ensure the latching relay does its bit when its supposed to, would be real nice. Any thoughts.  genuflect
Logged

Everything is possible, just give me TIME.
camillitech
Hero Member
*****
Offline Offline

Posts: 5415



WWW
« Reply #33 on: April 12, 2015, 10:56:00 AM »

Not the case here camilltech, these telecoms rectifier systems are really focused on efficiency as they run in huge numbers 24/7.
Even this old unit is likely pretty efficient, the latest ones are 97-98% IIRC.

Ours too are very efficient at their rated output, it's when they're just supplying a few watts that they're inefficient. Perhaps the Eltek ones are better, it's not really something I know much about. I've changed a couple as they seem to fail after about two years on a ship but that's probably due to vibration and salt air. I've got a 50amp one as a backup, backup and I have to say I'm much impressed with it but I wouldn't be wanting to leave it switched on 24/7.

Cheers, Paul
Logged

http://lifeattheendoftheroad.wordpress.com/

'Off grid' since 1985,  Proven 2.5kW, Proven 6kW direct heating, SI6.OH, 800ah Rolls, 4.75kW PV ,4xTS45, Lister HR2 12kW, , Powerspout pelton, Stream Engine turgo, 60 x Navitron toobs and a 1500lt store. Outback VFX3048 and 950ah forklifts for backup,
knighty
Hero Member
*****
Offline Offline

Posts: 2798


« Reply #34 on: April 12, 2015, 12:11:28 PM »

just to make it more complicated...

so you need 2 different under/over voltage thinges so you can set different voltages for day and night ?


so you can charge at night with cheap power if you need it

but so you can also supply power to the bank during the day if it gets low enough ?
(which I'm guessing might happen later on with all your gites running?)
Logged
clockmanFR
Hero Member
*****
Offline Offline

Posts: 3584



WWW
« Reply #35 on: April 12, 2015, 12:38:29 PM »

"I'm much impressed with it but I wouldn't be wanting to leave it switched on 24/7."

That's how I feel Paul. I have gone the route of switching On and Off with the AC Contactor on the Elteks 230vac Input, so when its off its OFF.

knighty..... I do not really trust those U&OV units, but have ordered a spare one.

At night I have no PV feed to the batteries, but have the wind Turbines when its windy, which is only about 40% of the time. The  battery voltage could drop low if some one in the Gites has left something on. Then the above circuit would kick in anyway.

I have a parallel circuit running with the Timer unit that will give the batteries, through the Eltek charger a fixed amount of cheap EDF and time of charge and using the Elteks set charge rate of 55v. But you are correct this circuit may need a flipping U&OVU.  Roll Eyes as the 55v charge voltage might false trigger the latching relay on the First U&OVU.  facepalm

Back to the drawing board.       facepalm
 
Logged

Everything is possible, just give me TIME.
Fionn
Hero Member
*****
Offline Offline

Posts: 545


« Reply #36 on: April 12, 2015, 12:40:04 PM »

No I don't think so knighty, the unit will give a pulse for either an under or over voltage condition so only one is needed. I think everything required is there with the exception of a DIN rail time clock perhaps if you he only wants to enable the system during night tarriff hours.
Camilltech, you are correct of course that every rectifier has some level of zero load consumption and efficiency is of course zero when it's idling. I don't know what the efficiency of his unit is or it's standby power consumption.
The newer Eltek FP2 HE 2kW units are around 98% efficient which suggests 40W of heat generated at worst, they certainly don't run their fans or anything at low / zero load so I'd guestimate standby is <5W for those. This one might be 40W perhaps given it's bigger and a lot older. Not as big issue if it's in a house that is electrically heated anyway Smiley
Logged

PV - 2.75kW East, 1.5kW South, 2.5kW West. 3 x Flat Plate Solar Thermal with side arm FPHE on 268L cylinder
Fionn
Hero Member
*****
Offline Offline

Posts: 545


« Reply #37 on: April 12, 2015, 12:44:31 PM »

Do you really need the over voltage cut out at all though?
The Eltek won't over charge the bank and it's power output will taper downwards as the bank recharges anyway.
Perhaps you just need a simple voltage divider circuit triggering a delay circuit to avoid short cycling and dispense with the U&OV unit entirely?
Logged

PV - 2.75kW East, 1.5kW South, 2.5kW West. 3 x Flat Plate Solar Thermal with side arm FPHE on 268L cylinder
clockmanFR
Hero Member
*****
Offline Offline

Posts: 3584



WWW
« Reply #38 on: April 12, 2015, 12:54:25 PM »

Fionn, ... "perhaps if you he only wants to enable the system during night tarriff hours."

I would actually like the first and preferred Only U&OVU to be active 24hrs 7 days, just in case.

But when I know that the Gites will be occupied I can switch the Clock timer circuit in and use the cheap tarrif EDF for its 7 hours, knowing I can supply the batteries especially on a No wind, No Sun day.

But somehow the Clock timer circuit and the rising battery charging voltage should not trigger the first U&OVU latching relay. Perhaps I can isolate the latching relay input by using the contacts on the Clock timer so when the Clock Timer Relay is activated the Latching relay can not receive any pulse?
Logged

Everything is possible, just give me TIME.
camillitech
Hero Member
*****
Offline Offline

Posts: 5415



WWW
« Reply #39 on: April 12, 2015, 12:59:48 PM »

It's just my 'off grid' head Fionn  Roll Eyes but like you say 5W is hardly going to flatten the battery.

Cheers, Paul
Logged

http://lifeattheendoftheroad.wordpress.com/

'Off grid' since 1985,  Proven 2.5kW, Proven 6kW direct heating, SI6.OH, 800ah Rolls, 4.75kW PV ,4xTS45, Lister HR2 12kW, , Powerspout pelton, Stream Engine turgo, 60 x Navitron toobs and a 1500lt store. Outback VFX3048 and 950ah forklifts for backup,
clockmanFR
Hero Member
*****
Offline Offline

Posts: 3584



WWW
« Reply #40 on: April 12, 2015, 12:59:59 PM »

"Perhaps you just need a simple voltage divider circuit triggering a delay circuit to avoid short cycling and dispense with the U&OV unit entirely?"

Yes Fionn that would be ideal.

Any hints of a simple voltage divider circuit and triggering a suitable timer, that's simple, robust, compact and cost effective, 48v or 24v dc, time span of settable 1 hour to say 4.  ?

  
Logged

Everything is possible, just give me TIME.
knighty
Hero Member
*****
Offline Offline

Posts: 2798


« Reply #41 on: April 12, 2015, 01:48:33 PM »

you could just use the under/over unit you have already to trigger a timer ? - there's plenty of cheap din rail timers on ebay ?

voltage gets low, UV unit triggers timer, timer runs for 4 hours, tripping on charger power for the 4 hours needed

have you checked the no load current of the eltek to see what it's like ?

if it's low enough, I still think you'd be better leaving it on low voltage 24/7

if you need to boost the battery up overnight, you could use one of the other chargers on a timer ?

there's a point where it's cheaper to run the base load of the eltek 24/7 and only take the minimum power in from the grid for charging - instead of all the times you would charge the batteries right before the sun comes out, or right before it gets windy, or right before your gites guests go home / remember they've left the fridge door open etc. etc.

with a base load of 50watts, and a charge rate of 4kw, you can power the base load for 80 hours for every hour of charging time you save

and you can save by shifting your charging hours to cheap night time power

using 14p day time 7p night time (rough uk numbers, no idea what you pay)

4kw for 4 hours at 14p - 2.24
4kw for 4 hours at 7p - 1.12

so if you shift 1 charge a week to night time instead of day time, you'll save 1.12
which would power the eltek for just short of a week at 50watt base load

add in a bit extra for all the times you don't need to charge, because the sun came out etc...



p.s. you know what you're doing / your system way better than any of us... I just like thinking up ideas / ways to do things - don't worry about telling me my ideas are daft or don't think that I'm saying you're doing it wrong / telling you what to do.... I just like the ideas process is all :-)


EDIT: I somehow typed the word 'sausage' instead of 'shift'.... no idea how that happened  wackoold
« Last Edit: April 12, 2015, 01:50:37 PM by knighty » Logged
jonesy
Hero Member
*****
Offline Offline

Posts: 839



« Reply #42 on: April 12, 2015, 02:55:49 PM »

Or, just to play devil's advocate, simply swap over from off grid to grid when the batteries are low during the day.  Why? the difference in cost between peak and off peak in France is 70% (0,1572/0,1096 inc vat).  You will not be 70% efficient charging/discharging batteries and using an inverter.  Grin
Once you've decided what on/off scheme you want CM let me know and I'll put together a fail-safe (!) circuit.
Logged

1.1kWp PV & SB1700. 7kW log burner.
biff
Global Moderator
Hero Member
*****
Offline Offline

Posts: 11964


An unpaid Navitron volunteer who lives off-grid.


« Reply #43 on: April 12, 2015, 04:30:36 PM »

This has become a very interesting thread,
                            A thread like this cannot help but grab my interest.
  The pics of the bits and bobbles + the diagram demand to be studied and digested, pondered and stored away.
  It speaks to me, " Biff me old son,, Pay attention,you will be looking at something very similar in the near future"
             Thank you Clockman et all.
                                         Biff
Logged

An unpaid Navitron volunteer,who has been living off-grid,powered by wind and solar,each year better than the last one.
clockmanFR
Hero Member
*****
Offline Offline

Posts: 3584



WWW
« Reply #44 on: April 12, 2015, 06:08:30 PM »

 whistlie Biff and his ferret things are now watching this topic............. Grin
Logged

Everything is possible, just give me TIME.
Pages: 1 2 [3] 4 5 6   Go Up
  Print  
 
Jump to:  

Powered by MySQL Powered by PHP Powered by SMF 1.1.20 | SMF © 2013, Simple Machines
SMFAds for Free Forums
Simple Audio Video Embedder
Valid XHTML 1.0! Valid CSS!