Dometic fridge wiring to Sargent EC160 advice

[nikmartin1]

Third post today. Not quite sure about wiring in the Dometic fridge with my Sargent EC160. There appears to be a couple of ins for it on the Sargent. I work with properties and so am fairly ok with wiring etc. But, I'm not quite sure what I'm supposed to be doing with the fridge. I think the wiring is to do with the fridge needing to be running constantly but not draining the leisure battery when driving? I can't seem to find a definitive video on the Sargent EC160. Any help would be really appreciated.

 

[Unimog]

I wired my fridge direct to the leisure battery with an in-line spade fuse. You Don’t want a voltage drop or you will find the fridge compressor will shut down. I turn mine of using the fridge thermostat.

Have a look at the web site for travel volts. Look on the advise page. the owner is a Martin, very helpful.

Electrics | Travelvolts

Welcome to Travelvolts, the UKs premiere supplier of custom electrics for camper vans and work vehicles.

www.travelvolts.net

 

[nikmartin1]

Thanks Unimog. I may be over thinking this. But I'm still a little confused. Please bear with me. I have a Sargent EC160 which appears to have 2 links for the fridge. Thats what's confusing me! I've not wired it up yet. I just have a 16mm battery cable coming from the leisure battery under my drivers seat threaded through ready to be screwed into the Sargent. But that cable appears to be far too thick to actually fit into the main feed screw inputs. Did I not need that thickness of cable?
But, your suggestion is that I need to have a direct link to the leisure battery for the fridge. With an in-line spade fuse. (what size cable would that need to be? 4mm or 6mm maybe?) Then just link the earth from the fridge to any earth (say the split relay earth).
What size cable would I then need to connect the leisure battery to the main Sargent unit? As the one I'm using (the same thickness as the one from the vehicle battery to the split relay) is too big to fit the Sargent. Hope this all makes sense (yep clear as mud!!!)

 

[Nigel W]

I have a Sargent box and can confirm that my fridge is connected directly to the leisure battery not the Sargent unit.
The fridge option on the Sargent box is for 3 way fridges as fitted in caravans and motor homes, not compressor fridges.
Cant help with wire size, way out of my knowledge base, but I do know that if you use too small wire it will not work properly.
Also just noticed you say ‘split relay’ you do know that these do not work correctly on a T6 and you should use a battery to battery charger?

 

[nikmartin1]

Hi Nigel, I didn't realise that the fixing was for a three way fridge. Thats good to know. And having read a few more forum posts I see that I do have to wire the fridge directly to the leisure battery. I think I've got the correct cable. It says its 16 amp rated. So should be ok I think. The wiring diagram that comes with the Sargent shows 15Amp fuses on the fridge cables so I'm guessing they should be fine. Also, I have a T5.1 not a T6. So the spit relay works ok. Maybe next year a T6 lol.

 

[Nigel W]

Hi Nigel, I didn't realise that the fixing was for a three way fridge. Thats good to know. And having read a few more forum posts I see that I do have to wire the fridge directly to the leisure battery. I think I've got the correct cable. It says its 16 amp rated. So should be ok I think. The wiring diagram that comes with the Sargent shows 15Amp fuses on the fridge cables so I'm guessing they should be fine. Also, I have a T5.1 not a T6. So the spit relay works ok. Maybe next year a T6 lol.

I’d stick with the 5.1, all the fancy euro6 stuff they have now stuck on is a pain - Adblu, regen braking, smart alternator, semi electric water pump etc.etc.

 

[nikmartin1]

Just a quick update on the install of my Sargent EC160 and the Waeco fridge wiring I couldn't get my head around previously. I wired the fridge as per the rather uninformative manual supplied by Sargent. I now know the main reason for having an in and out for the fridge on the Sargent was basically to run it through its own dedicated fuse! And now I also realise why most of the advice I was given by you guys on here to simply wire it straight to the leisure battery with an inline fuse was much simpler to do lol. Hindsight....what a wonderful thing. I now have a real long cable run from the leisure battery to the Sargent and then back to the fridge just to simply use its fuse. I'll know for next time. Everyday is a school day. It all works fine though. I used fairly decent tri-core cable as recommended by a cable company. These were still probably a bit overkill, but at least they fit ok into the Sargent. (with a bit of wiggling). Thanks everyone for all the the advice. Its really appreciated. Next time I'll listen. Nik

 

[nikmartin1]

A question regarding the operation of the Sargent EC160. Although most of the switches are obvious. I can't work out how the charge switch works. Does that just charge the Leisure battery when on 230 hook up. Or (because there is a switch with LB/Off/VB) will it boost up the vehicle battery as well. Or is that rocker switch simply to let you know what charge either battery has. I ask this as, when I've been doing all the work on the van with the doors open, my vehicle battery keep dropping and not having quite enough charge in to start the van. I've switched the interior lights off etc, but can't work out why its dropping. I have to keep plugging a battery charger in to boost it back up for half an hour before it'll start. Any ideas guys?

 

[Nigel W]

Great new, just check the fridge runs when the engine is both running and off.
reason is the Sargent box is designed for 3 way fridges so it only supplies 12v when engine running expecting it to use gas/mains when off.

 

[nikmartin1]

I think it should be ok. I've just wired it to the IN (which I'm guessing then goes through the fuse) and then taken a link from the OUT back to the fridge. There is a small link that they suggest on their installation wiring diagram that will turn the fridge off when the engine is running. And another one that seems to bring the split really part of the unit online. But I have'nt wired any of those bits up. (I already wired my own split relay in with the leisure battery) The actual explanations in their installation instructions a very vague at best! But I must admit, I haven't started the engine up with the fridge running yet to see if it does cut the power. I'll have a check tomorrow and let you now.

 

[Nigel W]

ok, if you haven’t connected the ‘run’ wire it won’t know if the engine is running or not.
on the charge side you have a switch which selects which battery to use, if the charger is off it will draw power from the selected battery, if the charger is on it will charge the selected battery (assuming you have wired it up as per instructions.
here is a link to the instruction page

System User Manuals | Technical Support | Sargent Electrical

 

[nikmartin1]

Ah, that's what I hoped it would do. So it should charge either battery. The built in split really should be nothing to do with that, is that correct? I've got the installation manual but it doesn't really seem very clear about the charging operation. I've wired everything as per the manual, all except the little links for the on of sensor for the fridge when driving and the internal split relay.

 

[Nigel W]

Top tip, buy one of these and stick it into your vehicle cig socket - it shows the state of your vehicle battery.
turn on the charger, switch over to vehicle and watch the meter leap up to show its receiving a charge.
it also lets you monitor the battery so you don’t flatten it again!

Dual USB Car Charger - JEBSENS Car Voltage Meter Car Charger with Two USB Ports, 4.8A / 24W, LED Display Built-in Safety Protection Fast Charging Compatible with All Smartphones and Tablets: Amazon.co.uk: Car & Motorbike

Dual USB Car Charger - JEBSENS Car Voltage Meter Car Charger with Two USB Ports, 4.8A / 24W, LED Display Built-in Safety Protection Fast Charging Compatible with All Smartphones and Tablets: Amazon.co.uk: Car & Motorbike

www.amazon.co.uk

 

[nikmartin1]

its the same instructions as I have. But.......I've re read part of it (can't believe I missed this bit....been a long few months!), and yes you're absolutely correct, it will charge either battery. Awesome. I must confess, I'm used to developing and re furbishing property. And kind of know what I'm doing after nearly 20 years doing it. But this is a whole new ballgame. I love every minute of it. But it can be somewhat confusing at times. I've made myself mini videos of every step of what I've done just to remind myself of what I did. When I do my next conversion it should be a piece of cake lol.

 

[nikmartin1]

Top tip, buy one of these and stick it into your vehicle cig socket - it shows the state of your vehicle battery.
turn on the charger, switch over to vehicle and watch the meter leap up to show its receiving a charge.
it also lets you monitor the battery so you don’t flatten it again!

Dual USB Car Charger - JEBSENS Car Voltage Meter Car Charger with Two USB Ports, 4.8A / 24W, LED Display Built-in Safety Protection Fast Charging Compatible with All Smartphones and Tablets: Amazon.co.uk: Car & Motorbike

Dual USB Car Charger - JEBSENS Car Voltage Meter Car Charger with Two USB Ports, 4.8A / 24W, LED Display Built-in Safety Protection Fast Charging Compatible with All Smartphones and Tablets: Amazon.co.uk: Car & Motorbike

www.amazon.co.uk

Cool, now I know what my daughter can buy me for Crimbo

 

[raylacey]

I’d stick with the 5.1, all the fancy euro6 stuff they have now stuck on is a pai

I’d stick with the 5.1, all the fancy euro6 stuff they have now stuck on is a pain - Adblu, regen braking, smart alternator, semi electric water pump etc.etc.

n - Adblu, regen braking, smart alternator, semi electric water pump etc.etc.

I have a 2016 T6, which has a Euro 5 engine, so does that mean I don't have to worry about the smart alternator ect. My 12 volt compressor fridge is wired through the sergeant and it's performance is erratic at best, so think I'll go for the direct from leisure battery option, to see if it improves. I'm also confused because I understand that the Sergeant has a split relay, and there is a smart relay fitted in the engine bay????
Does anyone know of a really good campervan electrician in South Wales?

 

[DXX]

I have a 2016 T6, which has a Euro 5 engine, so does that mean I don't have to worry about the smart alternator ect. My 12 volt compressor fridge is wired through the sergeant and it's performance is erratic at best, so think I'll go for the direct from leisure battery option, to see if it improves. I'm also confused because I understand that the Sergeant has a split relay, and there is a smart relay fitted in the engine bay????
Does anyone know of a really good campervan electrician in South Wales?

Some Euro 5 have smart alternators, they are Bluemotion models.

 

[raylacey]

Some Euro 5 have smart alternators, they are Bluemotion models.

Thanks DXX, that probably explains why I have something that calls itself a "smart relay" mounted in the engine bay, I will need to check the manufacturer and model and get more info on it. I know the fridge is currently running through the sergeant EC160 as I was able to remove the 15 amp fuse to reset the fridge. Think I'll definitely switch to a direct from leisure battery option.

 

[Mugsy]

For those wiring the fridge direct to the battery, are you doing both + and - to the battery or + to battery and - to ground?