NPS Camper Build

[gait]

The difference being that they actually convert the 110/240v AC to DC so they can vary the speed of a DC compressor efficiently. My father in law and myself were toying with the idea of working out how to run 1 direct from DC therefore bypassing the voltage conversion and making it more efficient.

Dazza

that would be a very nice project ............. yes please!

the Danfoss / Secop 12/24v DC fridge compressors have a brushless DC motor driven electronically (electronically commutated) with variable speed control. IMHO the available after market controllers (thermostat ++) aren't quite as sophisticated as commercial mains fridges (or air cons).

 

[LeishaShannon]

For us the decision was primarily based on availability and cost, its a lot easier to find parts or even a total replacement (ours was $500) for a household fridge vs a 12/24v DC.
The efficiency is "good enough" from the measuring I did with a fluke scope meter - it averaged 23W over a week , highest peak recorded was ~300W when it was first turned on. If we built a custom box with 4" thick insulation i'm sure we could use less power, but the build is taking too long as it is! The $2000 or so we saved over a DC fridge has gone toward more solar, batteries, and better inverters which benefits the entire electrical system.

 

[ianc]

I was going to go down that route also but the 12v->220v inverter was going to chew about 3amps constantly and so negated the saving going for a "mains" fridge. I'm using a Sterling CombiPro 2500.

 

[LeishaShannon]

Checkout the Victron Multiplus range, ours use around 8 watts idle. They have a couple of other really neat features for vehicle use:

PowerControl allows you to limit the incoming power to x (2 - 16) amps, so if you're running from a generator it will limit the total incoming power to match the available output. Priority is given to AC loads , and any left over power is used by the charger.

PowerAssist puts the inverter output in sync with the incoming supply, so you're able to "boost" the incoming power with the inverter output which is great because when combined with PowerControl it'll let you start a big AC load with a smaller generator than you'd otherwise need. You spec the generator on your base load rather than peak which saves weight and cost.

Hub-1 turns the system into a grid feed inverter - when our truck is parked at home (or in a friends yard) instead of drawing power its actually feeding power back into the grid lowering our power bill using the solar on the roof.

Because AC power is such an integral part of our truck we opted for 2 smaller units running in parallel to provide some redundancy, as all these features do make me a little weary of the complexity inside the box.

 

[LeishaShannon]

The air conditioner is running as efficiently as hoped, drawing just a few hundred watts after the initial cooling or heating burst. Unfortunately its pretty mild here at the moment so I haven't been able to collect any useful long term performance data, hopefully we'll get some warmer days so I can get an idea of how much power it'll use to keep us comfortable.



Solar is mounted ~120mm off the roof to provide cooling airflow for the panels and a summer roof for the camper. Power input has averaged ~4kWhr/day which I'm pretty happy with considering its winter and partially shaded in the mornings and afternoons.

 

[Iain_U1250]

Looks like you have a mobile power station Shannon, might be able to hire it our to Energex to boost the grid

 

[mrFelix]

you've come a long way from your first post at exploroz when you were considering a BT50 :Wow1:

 

[LeishaShannon]

Finally decided on new shoes



49mm taller , ~60mm wider



17.5 x 6.75 alloys rated at 2300Kg/5070Lbs with Kuhmo KRD02 9.5R 17.5 M+S tyres rated at 136 (2240KG/4938lbs)
Rear track is the same and the front is wider bringing it to within 30mm or so of the rear.
Not as good as super singles with the correct offset but better than dragging an extra wheel through the sand



Shame about the dirty hubs!

 

[Gatsma]

Nice alloy wheels! Who makes them? I was gonna guess Alcoa, but don't know if they're available down under.

 

[LeishaShannon]

Alcoa make similar wheels however these ones are made by http://www.fullchamp.com.tw

 

[Alastair D(Aus)]

Leisha,
Are the wheels approved for use in Aus? If so I may go that way too. Did you source them direct or through an agent here? A$ price ?

 

[Maxcustody]

Very impressive build!!

 

[LeishaShannon]

Hi Alastair

Yup, the wheels are for sale locally, I bought them from these guys in Brisbane http://www.ebay.com.au/itm/Weight-C..._Parts_Accessories&hash=item3a96e00c84&_uhb=1 , $230inc/wheel. They also have the chrome nuts to suit. I believe a few places in Sydney also stock them although not as cheap!
All up we spent less than $3500 for 6 wheels, tyres, and chrome nuts.

Shannon.

 

[SkiFreak]

All up we spent less than $3500 for 6 wheels, tyres, and chrome nuts.

A good price for sure... but are they actually legal?

 

[LeishaShannon]

For our truck downrated to 4490Kgs they are in QLD. The National Code of Practice requires SRW to be as wide as the combined width of the existing DRW however in Queensland both the NCOP and the Queensland Code of Practice are valid. The QCOP does not have the silly requirement of SRW being as wide as 2 x DRW.

You'd need to check with your local transport authority / engineer / approved person to see if they're Ok with your truck.