High Voltage Issue on CTEK/Sargent EC155

[RikParr73]

Hi all

Currently running this system on my 2017 T6 Euro 6:

CTEK 250SA DC-DC
Sargent EC155
Victron Smart Shunt
Victron MPPT 75/15
120w Solar Panel

System had been running fine, just back from a weekend away without issue, but on the school run yesterday the Sargent panel started alarming, the top right LED was also flashing green and I was unable to turn the Sargent on/off (engine running at the time). Turned engine off and Sargent stopped beeping and flashing, was able to switch on and everything working as normal.

I left it all day and when I went to do the school run pick up it was ok for about 10 mins and then started again. Turned off engine and all ok. So I checked the charging voltage on the Victron Smart Shunt app and could see (whilst the engine was running) it was putting out 15.20 volts, seems high? I kept the app open and when the voltage dropped below 15.0v the alarm stopped. So for some reason I suspect the CTEK is giving out too much voltage to the Sargent or there is an issue with the Sargent possibly? Not my area of expertise.

I thought it may have been to do with the freezing cold weather (read that Sargent's are temperamental in cold weather), but I ran the Planar for a good while to warm the van out, so not convinced this is the cause.

Any guidance appreciated.

TIA - Rik.

 

[mmi]

it was putting out 15.20 volts, seems high?

Purely by spec sheet: D250SA has temperature compensated charging voltage, thus at +5 °C when AGM charging profile is selected the actual voltage would be 14.7 V + (23 mV * 25°C) = 15.16 Volts.

 

[RikParr73]

Thanks, but I'm not using AGM and I don't understand tbh.

 

[Nigel W]

Now I could be talking rubbish here but it might be worth checking

my Sargent unit (a 325) has an alarm as you described which goes off if the engine is running and mains connected (to stop you driving off and ripping out the hook up cable).

mine became a bit temperamental and starting playing up so I found the wire which sent the ‘run’ signal to the Sargent unit which does three things -
A it turns on the split relay (which I didn’t need as I have a BtoB charger)
B. It turned off all the internal 12v lights and sockets powered by Sargent (to comply with some legal stuff but was a pain as you couldn’t turn back internal lights on with engine running)
and C. It turned the alarm on.

so it might be an idea to just disconnect this and see - i can’t help you with how as they are all wired up by converters differently but mine was a 5amp piggyback fuse in the fuse box by the passengers right leg.

hope this helps and I’m not sending you on a wild goose chase!

 

[RikParr73]

Thanks Nigel. I can normally run the lights and sockets with the engine running. I'll probably ring Sargent Tech Support before I start poking/pulling around and break something, was thinking someone may have had this exact issue before. I think based on MMI's response above then it's doing some form of compensate for the colder weather.

 

[Frazman]

Just picking up on this - I have the same/similar setup and have just had the same problem (worked fine for the previous 12 months….) only difference is my rear power doesn’t disconnect when driving (which I’m not concerned about) and have also noticed the ‘A’ lamp sometimes flashes intermittently when engine running.

Just spoke to Sargent and they advised to disconnect the solar which should fix problem, blaming voltage overload to be the cause.

They also advised that a relay should have been installed alongside the Ctek unit to work together. Apparently the manual shows this, but I don’t see it.
He explained the reasons for this (slightly over my head tbh) but said it provides better charging and a more professional finish.

Anyone else done this? Fitting a relay alongside the Ctek?

 

[Stuiemc]

Just picking up on this - I have the same/similar setup and have just had the same problem (worked fine for the previous 12 months….) only difference is my rear power doesn’t disconnect when driving (which I’m not concerned about) and have also noticed the ‘A’ lamp sometimes flashes intermittently when engine running.

Just spoke to Sargent and they advised to disconnect the solar which should fix problem, blaming voltage overload to be the cause.

They also advised that a relay should have been installed alongside the Ctek unit to work together. Apparently the manual shows this, but I don’t see it.
He explained the reasons for this (slightly over my head tbh) but said it provides better charging and a more professional finish.

Anyone else done this? Fitting a relay alongside the Ctek?

I’m currently fitting my electrical system and came over the same issue. You do need to fit a 30a 5 pin relay, I got mine from Halfords.

It basically disconnects the Sargent from the vehicle battery when the ignition is turned on. This stops the built in split charger from charging the vehicle battery but still allows you to charge using the mains charger when hooked up. If you have a ctek fitted you can use the vehicle and ignition switch connections for feeds.

I’m also not using the mains charger and have a dedicated charger so removed the fuse but still wanted them connected so I can check the voltage on the control panel. I also left the run cable out as my fridge runs on its own circuit and I want to use the equipment in the rear whist moving.

Hope this helps if it’s not too late.

 

[RikParr73]

Hi

Very helpful. I’m going to get a relay and install, however, my electrical skills aren’t top level! I’ve done a poor drawing below on how I think I need to wire it in. What I’m struggling with is how I locate the ‘engine run’? I have 1 wire that goes to the leisure battery bus bar that powers the Sargent control panel up but that’s all I can see output wise without of course checking from the EC155 loom itself. Can anyone help? Thanks.

 

[Dellmassive]

Hi

Very helpful. I’m going to get a relay and install, however, my electrical skills aren’t top level! I’ve done a poor drawing below on how I think I need to wire it in. What I’m struggling with is how I locate the ‘engine run’? I have 1 wire that goes to the leisure battery bus bar that powers the Sargent control panel up but that’s all I can see output wise without of course checking from the EC155 loom itself. Can anyone help? Thanks.

View attachment 157460

That will go BANG. !!

Don't connect anything up untill you have the schematic correct.

 

[RikParr73]

That will go BANG. !!

Don't connect anything up untill you have the schematic correct.

Really, ok, thought I'd done a good job there tbh lol!! I'll wait until someone can help, cheers anyway.

 

[Dellmassive]

It's shown above if you want to copy...

Your schematic shown the starter battery being grounded to the LB earth.... Not good.

Have another look at this.



..

The 5pin relay had 2x pins for control.

The 3x pins left are 1x power in and 2x power out.

You will need a relay that will pass the current... 30A in the diagram above.

 

[RikParr73]

Thanks, I think i'll leave it to a pro Appreciate your time.

 

[Stuiemc]

Yeah as Dell says above,

So on your relay

Pin 85 - Earth
Pin 86 - Ignition live (your ctek should already have one)
Pin 87 - Engine run (if you want the Sargent to turn all electrics off other than the fridge, it’s the solid red cable in the multi plug)
Pin 87a - To Sargent (green and brown cable)
Pin 30 - Fused 20a cable to vehicle battery

 

[RikParr73]

Yeah as Dell says above,

So on your relay

Pin 85 - Earth
Pin 86 - Ignition live (your ctek should already have one)
Pin 87 - Engine run (if you want the Sargent to turn all electrics off other than the fridge, it’s the solid red cable in the multi plug)
Pin 87a - To Sargent (green and brown cable)
Pin 30 - Fused 20a cable to vehicle battery

Thanks very much for taking the time to send this. I'm going to have to get a professional to do this as the cables will need locating from the sargent and then running to the seat. I'll pass this information on to them, once I find someone.