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Calira EVS 38/20 circuit diagram ?

77180 Views 50 Replies 24 Participants Last post by  GMJ
Before I get on to the manufacturers wonder if anyone has got a circuit diagram of the Calira EVS 38/20-DS/IU power supply unit.
I have the block diagram and installation and operating instructions.
At the moment the leisure and main batteries stay connected together at anything above 13.2 Volts even when the engine is switched off.
I want to change this to nearer 13.5 Volts. There are pots in the main unit but nothing to say which one does what.
I have several items (satellite being one) that will not operate until the charging circuit disconnects the two batteries ( igniton active error showing) and sometimes it can take 20-30 minutes for the volts to drop, unless I force the fridge into battery mode manually to load up the main battery. Usually I then forget to put the fridge back into automatic and end up with warm ice cream.
Also want to make the LED bargraph display what is actually at the battery terminals as opposed to what is on the wires at the control board end. The bargraph reads 0.2 volts low at present. This may be easier to do as there are only two pots on the control unit but always nice to know which one is the right one.

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More Calira EVS 38/20 woes

Since I am in France, all my docs are in French or German. Calira links are now redirected to Truma who don't seem very responsive.
My unit failed and tripped the camper RCD. I ordered and replaced the internal slowblow fuse and hopefully re-connected. Phut ! RCD gone again. SO ...
No obvious evidence of cooking but the transformer varnish looked a bit bubbled but without smell. Looked up the ETD44 transformer and discovered there is more than one type. I found one with 185-265V Primary and one with 65-125V. My guess is that the former is correct unless there are others ? Can HullRLFC provide more ? Does Owl459 use his ElecSol charger alongside the mains disconnected Calira so that other control panel functions still work ? It seems you can't use the Knaus Owners forum as a none member :-(
It is a while since this thread attracted any posts but I'm hopeful :)
PCB mounted transformer

Hi, received an email from this forum saying somebody had replied to this topic, ain't modern technology wonderful?

After trawling through stacks of emails, I eventually found the order receipt from Burklin, from where I ordered the transformer.

Your description sounds like your Calira unit has gone exactly the same way as the one I worked on. Paint bubbling on the transformer but no sign of overheating until you remove it from the PCB and look at the base.

I think the problem possibly comes from a leisure battery that needs replacing as it's drawing too much charge current from the unit and this transformer can't take the strain. That is my humble opinion, have you had your battery a while? If so, it may be worth buying a replacement as this problem may reoccur.

I've tried to put a link for the transformer supplier's website but the forum won't let me.

So instead, do a Google search for "VN30.18/10535".

You need the link that starts

"PCB Transformers, type Marschner E at Burklin-A World of..."

Click on that and the Buerklin part number is "35C574", it's about halfway down the page and has the following description.

"PCB Transformer 2.3VA 12V 191mA 230V VN30.18/10535"

You might recognise the last few letters and numbers as they are what's written on the transformer, if you can make it out!

Ended up costing around £13 with most of that being postage.

The unit I repaired is still going strong so I think it may well be worth your while having a go.

Best of luck.
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Visually different

HullRLFC thanks very much for your prompt response.
I got all excited until I found that the transformer you identified is probably not contained within my unit.
If you Google ETD44 you will see images of the part I think might be cooked though it is only a guess. There is nothing in my unit that is so well identified as the 35c574 one on Burklin, though there are a couple of parts that have a similar (but unmarked) top profile.
My leisure battery was replaced early last year and I had the camper hooked up over winter (in a barn) via a time switch so that power was applied only a few hours per day. When I discovered the problem, the battery was completely flat and has been recovering slowly on solar power alone (outside the barn !)
I'm coming round to the idea of a separate smart charger leaving the EVS in circuit but without mains. Hopefully the two units will work harmoniously and provide battery status for both batteries. I will have to try it out temporarily with an old simple charger I already have.
The ElecSol @ 10A seems highly priced tho' compared to other smart chargers @ 1.5-3.5A.
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I also downloaded a copy of the layout and decided it was too much for me. Gather that Calira will service and return items but at a cost of course. Didn't I read somewhere that they have no formed an allegiance with a UK company or was it the other way round?

Re: Calira

mike800966 said:
I also downloaded a copy of the layout and decided it was too much for me. Gather that Calira will service and return items but at a cost of course. Didn't I read somewhere that they have no formed an allegiance with a UK company or was it the other way round?

There was a post on the Knaus Owners forum discussion board back in March, mentioning Atlantic Motorhome Services in North Wales, who are evidently an approved Calira agent, and carry a number of new and refurbished units in stock.

Prices seem fairly good, but looks like they want your old unit as part exchange.

Failures of Calira 30/20, 38/20 and other units.

Hello, we are A & N Caravan Services and affiliated to Atlantic Motorhomes and we do repair Calira 30/20, 38/20 plus all other Motorhome and Caravan charger/PDU's.
HULLRLFC is correct when he says it is poor batteries that destroy these units. We are the UK's biggest repairer and stockist of remanufactured Calira units and almost every one we have seen has failed from a battery past its best.
If you want your Calira to last replace the batteries at least twice their warranty period, i.e. if it is guaranteed 12 months replace it at 2 years. If it is guaranteed 2 years replace at 4 years MAXIMUM.

Poor batteries are an issue with every habitation charger on every vehicle, whether it is a Burstner using a Reich e-Box, a Swift Caravan using a Nordelettronica or Hymer using Schaudt. It doesn't matter which forum you go on they all berate the Battery Charger manufacturer. You will find threads on the Swift forums about Nordelettronica chargers being weak and unreliable, yet we have seen owners on their first failure in 7 years of ownership. The owners, generally, that have little trouble never let the battery run flat. Don't keep it on hook-up in storage. Change the batteries regularly, etc.

To get the most out of your Charger unit (any make) :
Don't use a battery past it's best.

Do keep the battery near full charge by topping it up for 1-2 days once a month.

Don't keep the battery on charge all the time. A charger lifetime is calculated around the average Motorhome use of around 2 months a year. If you have your Calira hooked up to the Mains 240v all the time you will use 6 years life in 12 months.

If the battery goes flat, IT WILL BE DAMAGED, bin it. Sophisticated power units will cut all 12v to the MH when the battery voltage drops to 10.5v to prevent the battery from being damaged by further discharge. There is a very good reason they do this, don't let the battery voltage drop below 10.0v, if it does discard it.

Don't try to use the Calira to bring up a battery that has gone flat. You will just a hear a pop and notice a funny burning smell!!

If the battery is good but down on charge (not flat) the Calira will get warm for a short time as it brings it up to voltage, but will then cool down as the charge required by the battery drops. If the charger gets hot on mains 240v for a long time, there is clearly something amiss.
Don't add fans to your Calira to cool it down. We had one in for repair that had been charging 2 batteries that were 6 years old (how can a battery with a 12 month guarantee be any good at 6 years? Even the manufacturer didn't think it would be much cop after 12 months!!). The owner had fitted 2 cooling fans to keep the poor tortured unit from shutting down. The fans provided cool air to the temperature sensing shut down circuitry so it didn't shutdown. As a result the inside of the unit was like it had been inside an oven, every component was baked to the end of its life.

Don't use a bigger battery bank than designed. The calira 30/20 and 38/20 have chargers with a 20A output, using the general 10x rule of thumb they can support a bank of 200Ah, not the 440Ah (4 x 110Ah ) battery bank we saw recently. If you have/need a big battery bank please upgrade the infrastructure around it.

Please don't use a 'smart' charger to charge your batteries. Especially if you have a 220Ah bank and the charger has a 5amp output designed to support a bank no bigger than 50Ah!! If you really must then disconnect the battery from the MH first as they often have voltages as high as 17v.
We have lots of emails that start "everything was ok until my brother (it is always someone else that broke it :) ) connected his smart charger to the Motorhome and now the Fridge won't work and the Calira shutsdown and the heater control lights won't come on".
The most expensive we have seen was for a new Fridge 12v control unit, the truma heater controller, the Calira 38/20 AND the vehicle ECU. 'His Brother' thought he would start the engine to see if that provided a 12v charge, because the smart charger was still on and connected to 240v the 17.9v from the smart charger reached the starter battery when running the engine connected them together and .........
The ECU was £780 and the rest close on £1,400. His High street charger wasn't quite the money saver he thought it would be. Sorry, his brother.

Fitting a small high street charger of 6amp will never get a battery bank of 220Ah charged fully. This will damage them in a very short space of time through Sulphation. So you will then need new batteries.
I don't understand how spending £87 on a high street charger + £200 on batteries works out cheaper than a repaired Calira at £150, but then I never was very good at Maths?

If you visit the website you will find lots of info like the above, we have a Battery Technology page that will turn upside down everything you thought you knew about habitation batteries; a page on the Calira, the e-Box, the Schaudt Elektroblock, Solar Power in a Motorhome, etc

Sorry gone on rather a lot.
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Calira EVS30/20 Schematic
Hi Knausser, do you sti9ll have the Calira EVS 38/20 Schematic? The link in your post doesn't work.

Thanks for the circuit diagram. I printed it out on A4 and it was difficult to read. I've managed to expand it onto 9 pages of print. I looked up your analysis so far. Is your unit old. Mine is late 2005 with not many hours on it.
Hi Liamog, I have a dead Calira RCV 38/20, do you still have the circuit diagram?
Hi and welcome

You might be struggling to get answers from this thread as it is 10 years old.

Maybe start a new thread and see if that attracts attention?
  • Haha
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I am pretty sure they give you that warning if you start to reply to an old thread and the link referred to is actually from 2008. The poor chap who gave the long reply from aandncaravans has actually passed away.He was an absolute mine of information.
You are right Pete - there is a warning about an old thread. They are useful to read for any background info but it's much better to start a new thread as we know.
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