New Bus

Please feel free to describe your motorhome, campervan or caravan. (make, model, length etc)
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T1 Terry
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Re: New Bus

Post by T1 Terry »

volts times amps. 220V, 7.5 amps. electric 1650 watts.
My first guess was the air cond is not an inverter type, so the compressor start up current is between 7 and 10 times the run current ...... 11.5kw or 11500w peak that can be maintained for 30 secs min, but reading through the tech specs for the Harrier lite and the Harrier Plus both use inverter technology, yet for some reason the bigger capacity unit uses less power ...... so there must be some cheapening of the electronics in the Harrier Lite, maybe they don't unload the compressor and allow it to freewheel before it starts pumping ..... who knows
As far as the inverter, what model number and brand? Not all inverters are created equal ...
We had a customer arrive for the pre install check over and was excited telling us about the 240vac fridge freezer she bought and the bargain Kings 3000w inverter. The fridge only draws 9.5 amps once it's running, 120w, yet the 600w inverter she has screams on startup and shuts down. Plugged into the 3,000w inverter, no problems, but a 100 amp plus draw to start up the compressor, 1200w start up, so in that case it was 10 times the run current. 1200w was no problem for the 3,000w inverter, but it draws 1.5 amps on standby, that 36 Ah per 24hrs just to have it turned on, so the 45 Ah per 24hrs the fridge would use now has another 36 Ah added to it, so now it's 80 Ah to power a 118ltr fridge :o
A closer look at the inverter and the label is very carefully worded, 3,000w DC to 240vac power inverter .... the draw is 3,000w, not the output :roll:

The fix for your set up, you need a 3,000w output inverter with a 3 times the capacity peak load that can be maintained for 30 secs or more. That means either a W7 / W10 cheap big lump of a thing like this eBay item number:373846458155 might not enough to start that air cond up, maybe a Victron 3,000va multiplus with the big toroidal transformer ( https://www.iqsdirectory.com/articles/e ... d%20losses. ) because the big transformer can carry a big overload for a short period, but not the Victron Multiplus 2 because it doesn't have the massive transformer.
Roof top rattlers no matter what technology is used, take more power to start up and run than a household 240vac split system unit does, but they still demand the peak power a non inverter compressor unit does when at peak load when trying to rapid cool or rapid heat an area, just that it can drop back on the load is the econ or night setting is used, it just takes longer to reach the selected temp ....

T1 Terry
A person may fail many times, they only become a failure when they blame someone else John Burrows
If we have data, let’s look at data. If all we have are opinions, let’s go with mine. – Jim Barksdale, former Netscape CEO
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T1 Terry
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Re: New Bus

Post by T1 Terry »

Just read back through the posts and the inverter is the baby Enerdrive unit, no hope of running an air con of one of those. You might be able to run it off the bigger unit, but it would need to be a dedicated unit only for the air con and possibly up to 4mm sq cabling to minimise losses between the inverter and the air con unit due to the cable run length. Hopefully the people doing the 240vac cabling have read the rules and used at least 2.5mm sq cabling, otherwise it will all have to be rewired ...... just finished one of those jobs and I can assure you it's not cheap to replace cabling after the rig is completed .....

T1 Terry
A person may fail many times, they only become a failure when they blame someone else John Burrows
If we have data, let’s look at data. If all we have are opinions, let’s go with mine. – Jim Barksdale, former Netscape CEO
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Vik351
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Re: New Bus

Post by Vik351 »

T1 Terry wrote: Fri Apr 28, 2023 12:09 pm Just read back through the posts and the inverter is the baby Enerdrive unit, no hope of running an air con of one of those. You might be able to run it off the bigger unit, but it would need to be a dedicated unit only for the air con and possibly up to 4mm sq cabling to minimise losses between the inverter and the air con unit due to the cable run length. Hopefully the people doing the 240vac cabling have read the rules and used at least 2.5mm sq cabling, otherwise it will all have to be rewired ...... just finished one of those jobs and I can assure you it's not cheap to replace cabling after the rig is completed .....

T1 Terry
How hard to fit a Victron Pheonix 3000 in there then ...???
what the hell sq cable ...??? sum fing new ... :-o

vik...
Merk 4x4 VF30 519 CDI 2020 LWB V6TD 3 ltr 6 wheeler ,Tenorite Grey ... yep, it's not white ...!!! 8-)
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jon_d
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Re: New Bus

Post by jon_d »

I've got an idea. One of many of my ideas.

Create a tikky tokkie account and video the interaction with the designers and builders.
You'll have a gazillion views and all will be free after that.

Actually imagine a channel. Bernie could add his weather adventures. The first title could be Bernie's Spring. :roll:
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T1 Terry
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Re: New Bus

Post by T1 Terry »

The copper conductor inside the insulation in a piece of electrical wire is measured in square mm (sqmm) the more square mm of area the conductor has, the less the voltage drop as the current (amps) are increased. If the number of amps is greater than the cable can carry over the distance from the inverter to the air conditioner, some of that power the inverter produced is converted to heat energy along the cable.
Using the voltage x amps to get watts, the air conditioner requires a certain number of watts to start spinning, if some of those watts supplied by the inverter get used along way up the cable as heat, more watts are required to get the same number of watts at the air conditioner forcing the inverter to increase the watts it is putting out, all because the conductor was too small. If the demand for watts is greater than the inverter can produce, the over load alarm sounds and the inverter shuts down.

As far as fitting a Victron Multiplus 3000 in the space you have available, no idea, I don't know how much space you have that can be utilised. The dimensions of the Victron Multiplus are here https://www.victronenergy.com/upload/do ... 3000VA.PDF and the installation manual recommends 10cm (100mm) clearance all round and good air flow to remove the heat from the area.

No idea why manufacturers interchange between mm and cm, only dress makers use cm ;) :lol:

T1 Terry
A person may fail many times, they only become a failure when they blame someone else John Burrows
If we have data, let’s look at data. If all we have are opinions, let’s go with mine. – Jim Barksdale, former Netscape CEO
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Vik351
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Re: New Bus

Post by Vik351 »

if some of those watts supplied by the inverter get used along way up the cable as heat, more watts are required to get the same number of watts at the air conditioner :shock:

Aint is supposed to be 240 AC runnin the thing outa the inverter FFS ...???

Startin to get to the OMG stage ... :evil:

Stay home and grow vegies ...

vik...
Merk 4x4 VF30 519 CDI 2020 LWB V6TD 3 ltr 6 wheeler ,Tenorite Grey ... yep, it's not white ...!!! 8-)
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jon_d
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Re: New Bus

Post by jon_d »

If you grow enough, you'll need a van to drive to the vege markets. Lucky eh.
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Vik351
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Re: New Bus

Post by Vik351 »

jon_d wrote: Fri Apr 28, 2023 7:21 pm If you grow enough, you'll need a van to drive to the vege markets. Lucky eh.
Good point , was gunna piss the thing off , but will keep it now, just wont have any AC in the back ... ;)

vik...
Merk 4x4 VF30 519 CDI 2020 LWB V6TD 3 ltr 6 wheeler ,Tenorite Grey ... yep, it's not white ...!!! 8-)
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Vik351
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Re: New Bus

Post by Vik351 »

OMFG ... thought havin a 15' clinker hull with a 6 pot red band was a money pit ... :o ...!!!

This MO FO is much hungrier FFS ...!!!

Got the new 3000 inverter ,then they tell me I need extra tingo, a Filax automatic transfer switch , they reckon the old 2000 enerdrive had one built in

Where is Terrence when ya need hum FFS ... :x :x :x

Lube will be extra ... :o :oops: :cry
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Merk 4x4 VF30 519 CDI 2020 LWB V6TD 3 ltr 6 wheeler ,Tenorite Grey ... yep, it's not white ...!!! 8-)
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jon_d
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Re: New Bus

Post by jon_d »

Does the AC work now Vic?
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