Go Back   The Navara Forum > New Members > New Members Area

Reply
 
Thread Tools Display Modes

  #11  
Old 29-05-2015, 04:03 AM
NAV012's Avatar
NAV012 NAV012 is offline
Senior Member
 
Join Date: May 2015
Location: Dubbo
Posts: 306
My Mood:
Garage
Default

I have never had that trouble buddy pics just come up
__________________
2012 D40 St -> HIS as below ;)
2014 Ford territory Tdi -> HERS

NAV012
Factory sidesteps--MR Monster Rides rekon coilovers and long travel shocks-- 4X4PARTS adjustable shakels-- OL Opposite Lock 3loop bullbar-- 2x 4" osram led spotties -- Wetsuit seatcovers --265/65R17 Maxxis Bravo 980
Reply With Quote
Sponsored Links

  #12  
Old 29-05-2015, 06:40 AM
Old.Tony's Avatar
Old.Tony Old.Tony is offline
Administrator
 
Join Date: Oct 2009
Location: Mid Coast Region, NSW, Australia
Posts: 15,306
My Mood:
Garage
Default

Quote:
Originally Posted by Farmer Joe View Post
Old Tony are you saying that if we have a 240volt inverter we are better off running our fridges on 240 rather than 12v?
Absolutely, and Happy John has explained it quite well.

The 12V heater doesn't produce as much heat as the 240V one, yet they both use about the same watts. I think my new van's fridge is 330W on 12V and 380W on 240V.

Because it doesn't produce as much heat, it's basically employed as a "maintenance mode" - designed to operate while you're driving (and you're obviously not in the back and opening the fridge).

The first drawback for us is that if we stop to have lunch somewhere, we're going to open that fridge (especially in summer, where the hell else do you store the beer? It's not bloody England!) and in the 12V "maintenance mode" the fridge isn't really going to return to its previous level of coldness by the time of our next stop.

The second drawback is if we really do a long haul (we've done Marla -> Balranald in one stretch) as John points out the food would freeze because it doesn't know when to stop.

If you're going to pull that many amps, cater for a few more and let the fridge work like you'd expect, is my motto. I built a little circuit that auto-switches from mains power 240V to the inverter-supplied 240V and back again without interference. I can run the fridge on 12V as well - it's all still connected (to the same wiring) but I prefer functionality.

The only thing I suggest is that you test the connection between the neutral outlet of the inverter and the battery negative input. There should be NO connection. If there's a connection, your inverter is NOT electrically isolated and may present a risk of shock when touching the car/van.
__________________

Check out the FAQs by clicking here!



"Money can't buy happiness, but it does make misery a lot easier to deal with."
Reply With Quote

  #13  
Old 29-05-2015, 06:50 AM
Old.Tony's Avatar
Old.Tony Old.Tony is offline
Administrator
 
Join Date: Oct 2009
Location: Mid Coast Region, NSW, Australia
Posts: 15,306
My Mood:
Garage
Default

Quote:
Originally Posted by Hillysfolly View Post
The fridge info is new to me but as an old ex sparky it makes sense.
I do have dual bats on patrol. But I have a question.....the isolator is just one of those old fashioned solenoids. What are the advantages of the new electronic isolators. I'm on a tight (lycra tight!) budget as I'm basically setting up three vehicles. If I can use what I have I'll try and make do.
The expensive isolators are nice and they make sure your battery gets fully recharged but as an ex sparky you'll understand the following really well.

Your starter motor needs about 500A to crank the car over, and in the 5 seconds that it takes to do that you'll draw a total of 5*500/3600 = 694mAh, which is considerably less than the energy in a standard AA battery. That's a piece of cake for your alternator to provide, and you'll often find that seconds after you've started your engine, the voltage is already at >14.1V and the isolators would all be active anyway (they cut in at 13.2V).

So, do you NEED a fancy isolator? No. A decent relay operating off a ignition-on supply will do the job nicely.

Quote:
Originally Posted by Hillysfolly View Post
And Nav012 I tried dropping in some pics from photo bucket and the preview looked to have worked but when I posted it I got a message about it having to be reviewed by moderators and I haven't seen it on site yet. Is this normal and how long does it take?
Thanks guys.
The forum only has two administrators now and I haven't seen them in absolutely ages. They will approve your posts as soon as they can.

Oh wait, a mirror - there's one! Catch him!
__________________

Check out the FAQs by clicking here!



"Money can't buy happiness, but it does make misery a lot easier to deal with."
Reply With Quote

  #14  
Old 29-05-2015, 09:29 AM
Hillysfolly Hillysfolly is offline
Junior Member
 
Join Date: May 2015
Location: Yorke Peninsula SA.
Posts: 25
Default

Thanks Old.Tony. Good to know I can use the solenoid. I see my post with the pics is now up......looks like one of the administrators was just snoozing on the job! At least I know I did it right for next time.
And your maths had me for a bit. P=IV and all that. I did my time with ETSA but dropped out shortly after finishing my apprenticeship and chose a career in professional photography so I'm a bit rusty on all the old electrical stuff these days. And 12v always had me scratching my head cause I could never figure where to hook that third wire haha.
Reply With Quote

  #15  
Old 29-05-2015, 10:45 AM
Old.Tony's Avatar
Old.Tony Old.Tony is offline
Administrator
 
Join Date: Oct 2009
Location: Mid Coast Region, NSW, Australia
Posts: 15,306
My Mood:
Garage
Default

The administrators aren't actually employed, they're just guys like you and me that hang around the forum a lot.

Hint: they're guys that are a LOT like me.

Stronger hint: look at the title under my name in this post.

As for the third wire ... I thought that was for better reception?
__________________

Check out the FAQs by clicking here!



"Money can't buy happiness, but it does make misery a lot easier to deal with."
Reply With Quote

  #16  
Old 30-05-2015, 01:51 AM
Hillysfolly Hillysfolly is offline
Junior Member
 
Join Date: May 2015
Location: Yorke Peninsula SA.
Posts: 25
Default

Yeah I did get that Tony. Was just having a gentle dig at ya! Outa interest, what's your background if you don't mind me asking? You seem to have a pretty good handle on electrical stuff. Or is that just from a lot of playing around with 12volt systems? Or is there an engineering background or something there?
Reply With Quote

  #17  
Old 30-05-2015, 01:57 AM
Hillysfolly Hillysfolly is offline
Junior Member
 
Join Date: May 2015
Location: Yorke Peninsula SA.
Posts: 25
Default

And what would be the chances of having a look at your circuitry for the auto switching from mains to inverter? It's something I could find useful too I reckon.
Reply With Quote

  #18  
Old 30-05-2015, 05:00 AM
Old.Tony's Avatar
Old.Tony Old.Tony is offline
Administrator
 
Join Date: Oct 2009
Location: Mid Coast Region, NSW, Australia
Posts: 15,306
My Mood:
Garage
Default

There's a bit of engineering (primary focus actually on high energy physics) and a lot of tinkering.

The "circuit" is really rather simple and is based around this relay from Jaycar. Here's the circuit - it's a little mashed up around the relay but I didn't want to have a common neutral.



The "plug into mains" is really just the end of an extension lead. All of the joins are done under the double power point which I mounted on a raised block. Even the relay fits in there, so all you really see is a board with a power point, inverter and a couple of cables.
Attached Thumbnails
Click image for larger version

Name:	240V Inverter Relay Circuit.jpg
Views:	167
Size:	67.4 KB
ID:	20321  
__________________

Check out the FAQs by clicking here!



"Money can't buy happiness, but it does make misery a lot easier to deal with."
Reply With Quote

  #19  
Old 31-05-2015, 12:38 PM
Hillysfolly Hillysfolly is offline
Junior Member
 
Join Date: May 2015
Location: Yorke Peninsula SA.
Posts: 25
Default

Thanks Old.Tony. I might try and do something similar. Looks like a simple solution. So the inverter is powered up all the time supplying 240v to the fridge but as soon as you plug the socket into the mains the relay changes over and isolates the inverter and supplies the fridge with mains power?
Reply With Quote

  #20  
Old 31-05-2015, 08:14 PM
Old.Tony's Avatar
Old.Tony Old.Tony is offline
Administrator
 
Join Date: Oct 2009
Location: Mid Coast Region, NSW, Australia
Posts: 15,306
My Mood:
Garage
Default

It works the other way around but could easily work your way by switching the feeds from mains/inverter to the opposite side of the centre relay poles. The NC connection means "Normally Closed" which is like the "default connection", so with everything hooked up but the car switched off, the circuit supplies power from mains through the relay to the double power point. Turning the car on activates the relay (and turns on the inverter) and so power is supplied to the power point from the inverter instead.
__________________

Check out the FAQs by clicking here!



"Money can't buy happiness, but it does make misery a lot easier to deal with."
Reply With Quote
Reply

Tags
campervan, home schooling, patrol, qd32, tinny

Thread Tools
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off

Forum Jump



All times are GMT +1. The time now is 02:37 PM.



Powered by vBulletin® Version 3.8.7
Copyright ©2000 - 2020, vBulletin Solutions, Inc.
| Home | Register | FAQ | Members List | Calendar | Today's Posts | Search | New Posts |