Inverter Cooling Fan

Submitted: Wednesday, Feb 20, 2008 at 11:37
ThreadID: 54746 Views:2232 Replies:5 FollowUps:18
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Just tested new inverter with 100w globe, works fine, but fan did not run. Book says ..check fan is running when inverter is operational. Bugger. Then in spec list at back of book says fan in
my inverter (1200W) is auto controlled by temp & load.
Does anyone know if this is correct? I have contacted supplier by email but no response as yet but
would welcome input from the gurus of EO that are inverter
literate. cheers...oldbaz.
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Reply By: Mike Harding - Wednesday, Feb 20, 2008 at 11:45

Wednesday, Feb 20, 2008 at 11:45
Sounds like a good way to do it to me.

If the inverter is only powering a small load it won't need a fan running all the time so they save your battery power by only switching it on if the internal temperature rises too high or the inverter is running a heavy load which will cause it to heat up.

All sounds good to me Oldbaz. If you're concerned just place the palm of your hand on the hottest side of the inverter and providing it's not too hot to keep your hand there it should be OK.

Mike Harding
AnswerID: 288425

Follow Up By: stefan P (Penrith NSW) - Wednesday, Feb 20, 2008 at 13:16

Wednesday, Feb 20, 2008 at 13:16
what mike said..........my 1500watt inverters fan hardly ever comes on, only on the hottest days ie over 35 deg.

Cheers Stefan
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Follow Up By: Member - Oldbaz. NSW. - Wednesday, Feb 20, 2008 at 16:26

Wednesday, Feb 20, 2008 at 16:26
Thanks gents, right again. Supplier has advised that fan is indeed thermo controlled so all is well....oldbaz.
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Reply By: Nomadic Navara - Wednesday, Feb 20, 2008 at 16:14

Wednesday, Feb 20, 2008 at 16:14
100 W is not what you would call a load for that inverter. Put a decent load on it and see what happens. Perhaps connect it to what you intend to run on it.

PeterD
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AnswerID: 288454

Follow Up By: Member - Oldbaz. NSW. - Wednesday, Feb 20, 2008 at 16:35

Wednesday, Feb 20, 2008 at 16:35
Peter, you are right about the load. Supplier says fan is thermo controlled so all is well. Only intend to run 3way fridge at this point
but may add waeco/Engel later. The cost of this capacity inverter
is less than $100 so decided to go for a bit more spare capacity.
Yes I know it is Chinese, but what the hell. Someone told me
Waeco is built in China now anyway but not sure about that.
cheers...oldbaz.
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Follow Up By: Mainey (wa) - Wednesday, Feb 20, 2008 at 18:22

Wednesday, Feb 20, 2008 at 18:22
I hope you have a really good battery and charging system to be running a 3 way fridge from an inverter !

Mainey . . .
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Follow Up By: Member - Oldbaz. NSW. - Thursday, Feb 21, 2008 at 19:10

Thursday, Feb 21, 2008 at 19:10
Mainey, Fridge draws 75w on 12 or 240v. Hardly a big task for
an alternator, battery not a big factor either. Can you explain
further. Always ready to listen. As mentioned earlier I have evidence of 3way runing off inverter on single battery system for
many years with no problems. The user travels 6 months of the year....oldbaz
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Reply By: oldtrack123 - Wednesday, Feb 20, 2008 at 17:43

Wednesday, Feb 20, 2008 at 17:43
Hi OLD BAz
If your battery system is 12v why run thro an inverter to get 240v extra power losses that way
If fridge does not work ok on 12v itis proably due to wiring being too small for cable run length.
check with meter if you are not getting around 11 volts or better at its terminals it needs rewiring with heaver cable.
AnswerID: 288471

Follow Up By: Member - Oldbaz. NSW. - Wednesday, Feb 20, 2008 at 18:24

Wednesday, Feb 20, 2008 at 18:24
G'day, you are right about fridge not working on 12v. But problem
is not voltage drop as the wires I run direct from the battery
give me excellent voltage at the end of a 3m run...6sq mm or
whatever. I believe the problem is the 12v element contained in a very unserviceable position. 240v heats an adjacent element & works fine. Hence the inverter .. brotherinlaw..retired leco has run
his Chescold this way for many years, paid a fortune for the 300w inverter, but reckons fridge will run forever on the more stable
power source....oldbaz.
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Reply By: Mike Harding - Wednesday, Feb 20, 2008 at 17:50

Wednesday, Feb 20, 2008 at 17:50
Oldbaz; the above post reminds me to mention to you that you'll need to mount the inverter as close to the battery as possible, although _not_ in the engine compartment, the reason, as I suspect you already know, is to keep the high current 12V leads as short as possible otherwise you'll still have voltage drop problems.

Mike Harding
AnswerID: 288473

Follow Up By: Member - Oldbaz. NSW. - Wednesday, Feb 20, 2008 at 18:32

Wednesday, Feb 20, 2008 at 18:32
Mike, I hear you, will try the current wiring & see how it performs.
Some net research has revealed that some have successfully
mounted in the engine bay in the US, but the size of my inverter
may pose problems. The heat,again being the main factor to
overcome. I will do some underbonnet temp tests as it would be an ideal solution if feasible. Thanks again for your interest, I'll
keep tinkerin.....oldbaz.
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FollowupID: 553825

Follow Up By: Mainey (wa) - Wednesday, Feb 20, 2008 at 18:35

Wednesday, Feb 20, 2008 at 18:35
Oldbaz,

D O N ' T even think about putting a 1200 Watt Inverter in the engine bay !!!

Mainey . . .
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Follow Up By: Mike Harding - Wednesday, Feb 20, 2008 at 18:37

Wednesday, Feb 20, 2008 at 18:37
Oldbaz....

Mainey and I are both cringing :)

If you put it underbonnet it _will_ die before long. How about at the top of the passenger footwell?

Mike Harding
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Follow Up By: Member - Oldbaz. NSW. - Thursday, Feb 21, 2008 at 19:17

Thursday, Feb 21, 2008 at 19:17
Hey ,gents lighten up, & cease cringeing. The inverter wont go in the engine bay unless I am sure of its capacity to operate in that
environment. I have already indicated that I will do tests to ascertain if that is viable. Your concerns will be far more useful if
you convey the reasoning behind them. As said before..always ready to listen ...oldbaz.
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Follow Up By: Mike Harding - Thursday, Feb 21, 2008 at 19:29

Thursday, Feb 21, 2008 at 19:29
>Your concerns will be far more useful if
>you convey the reasoning behind them.

It'll be too hot and wet in that environment.

Mike Harding
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Follow Up By: Member - Oldbaz. NSW. - Thursday, Feb 21, 2008 at 19:57

Thursday, Feb 21, 2008 at 19:57
Thank you Mike, I dont disagree, but there is a lot of electrical gear operating very satisfactorily in that same environment. i dont
see the "wet" part as anything that cant be overcome. The heat
will be the limiting factor, space too I fear. cheers...oldbaz.
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Follow Up By: Mainey (wa) - Thursday, Feb 21, 2008 at 23:07

Thursday, Feb 21, 2008 at 23:07
Oldbaz, we are talking about 240 Volt.

question: would you operate the Inverter out in the rain in a storm ??

is exactly the same thing, water and moisture is 'moved' around in the engine bay as you drive, the Inverter is NOT sealed against water, and it is producing 240 Volts.

I bet the Inverter installation information states it should NOT be used where there is ANY likelihood of moisture possible, I know of no Inverter that states it is suitable for using 'outside' or in wet conditions.

The Heat will not be a *major* problem, it's the moisture that will kill you, not the heat.

Mainey . . .
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Follow Up By: Member - Oldbaz. NSW. - Friday, Feb 22, 2008 at 09:15

Friday, Feb 22, 2008 at 09:15
Mainey, I understand where you're coming from & the danger of 240v. I'm not sure that a rainstorm & the underbonnet conditions
during rain can be compared. It pleases me that you think heat is
not the biggest issue as I reckon I can seal the inverter from moisture & duct the fan intake to where moisture wont tenter. The outlet can also be suitably protected.
Anyway, as said previously ,this option will only be investigated if current wiring proves unsuitable. Guess I'm just a stubborn old coot who wont take no for an answer, but I've always been inclined to question why things cant be done .
Thanks for your help.....oldbaz.
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Reply By: Member - Mike DID - Wednesday, Feb 20, 2008 at 18:25

Wednesday, Feb 20, 2008 at 18:25
Using a 1200 watt Inverter to a run a 150 watt fridge is very wasteful as the inverter will be very inefficient with such a small load.

You're better off getting a small Inverter when you only want to power a small load.
AnswerID: 288475

Follow Up By: Mike Harding - Wednesday, Feb 20, 2008 at 18:35

Wednesday, Feb 20, 2008 at 18:35
If memory serves (from previous posts) Oldbaz only wishes to run his fridge in this mode whilst he is driving and in order to avoid messing around with heavy gauge wiring. As three way fridges are very heavy on electrical power it would not make much sense to use them in either electrical mode unless mains 240V or engine produced 12V was available.

Mike Harding
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FollowupID: 553826

Follow Up By: Member - Oldbaz. NSW. - Thursday, Feb 21, 2008 at 19:47

Thursday, Feb 21, 2008 at 19:47
Mike R, mate I'm only a simple sheep cocky, but I cant find any
logic in your assessment of wasted capacity. I'm saying I only got
a 200kw LC in case I want to tow a caravan one day. Who knows
what I might want to power with this inverter as time goes on?
If I've missed something please straighten me out. It is my
understanding that this inverter will produce no more output than is asked of it. The supplier has advised that the cooling fan will only operate at higher load limits, & rarely if load is low. Where is
the inefficiency?
Mike H, you are correct in that the fridge will only be run while
alternator is operating. Gas used when stopped overnight or longer
cheers...oldbaz.
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FollowupID: 554022

Follow Up By: Member - Mike DID - Thursday, Feb 21, 2008 at 20:14

Thursday, Feb 21, 2008 at 20:14
Oldbaz - if you're only going to use the Inverter while you've got teh engine running then there's no need to worry about wasting a bit of power.

In case you're running on batteries, here's the explanation.

It's the same with engines - you'll use a lot more fuel if you use an engine that's way oversized for the load. If you want to run a 2 HP alternator, you would use less fuel running a 100cc engine at full revs rather than a 5 litre engine just above idle.

An Inverter will only run at its maximum efficiency ( let's assume 90%) when putting out close to full power. So a 200 watt Inverter will draw 150+15 watts when putting out 150 watts.

Even when it's producing zero output, an Inverter is still drawing current. So a 1200 watt Inverter may draw 50 watts when putting out low power, so it would be drawing 150+50 watts to produce 150 watts.

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Follow Up By: Member - Oldbaz. NSW. - Friday, Feb 22, 2008 at 09:21

Friday, Feb 22, 2008 at 09:21
Mike R, thanks for the explanation, sounds good. I think I may have muddied the water a bit by not stating clearly the intention to only run inverter while alternator is running......oldbaz.
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