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Old 24-03-2013, 17:49   #1
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double the inverter double the wattage?

Can I hook two 1200 watt inverters together to continuously power a 2400 watt appliance?.... reason I'm asking is because its cheaper to buy two 1200s than it is to buy one 2400...
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Old 24-03-2013, 17:54   #2
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Re: double the inverter double the wattage?

Sorry, it is not a good idea to do that! Mauritz
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Old 24-03-2013, 17:55   #3
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Re: double the inverter double the wattage?

Generally no.
AC power is sine wave. Inverters have to be in sinc to produce the same waveform.
Unless the inverters have an intelligent link mode they cannot be bridged.
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Old 24-03-2013, 17:56   #4
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Re: double the inverter double the wattage?

no,one will blow the other up!
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Old 24-03-2013, 17:56   #5
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Re: double the inverter double the wattage?

yes you can, but only once
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Old 24-03-2013, 18:10   #6
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Re: double the inverter double the wattage?

Some inverters are stackable but I don't know any that are cheaper watt per dollar than the same output in a single inverter after the cost of the two smaller inverters, and the stacking interface and cables.

If you have large loads (your citing a 2400 watt appliance) I would go with a 48 volt battery bank and 48 volt inverter if your using lead acid batteries with their poor Peukert effect at high discharge. If your going to upgrade to LiFePO4, then a 2400 watt load isn't a problem staying with 12 volts. 2400 watts @ 12 volts is going to pull 200+ amps, 50 amps @ 48 volts.
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Old 24-03-2013, 18:14   #7
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Re: double the inverter double the wattage?

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2400 watts @ 12 volts is going to pull 200+ amps
Yikes! Get some big wires on there.
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Old 24-03-2013, 18:21   #8
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Re: double the inverter double the wattage?

Need to consider the type of appliance rated at 2400 W. If an inductive (i.e., motor) load, inrush requirements may be way over 2400 W.
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Old 24-03-2013, 18:56   #9
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Re: double the inverter double the wattage?

must be some way to parallele them as Hondas generators can do it

but I bet no 1200W inverter is designed for this and it is less expensve to just get the bigger unit..........

and then there is the space to consider
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Old 24-03-2013, 23:25   #10
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Victron multiplus can be connected together for more power. Up to six units can be paralleled either 2kw or 3kw depending on model.

http://www.victronenergy.com/inverte...8v-800va-3kva/
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Old 25-03-2013, 02:11   #11
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Re: double the inverter double the wattage?

A lot of things are possible if the pockets are deep enough. In order to tie two or more inverters together, they need to have circuits called, tie-line controllers, that sync the multiple units to produce a common output. If you take two regular cheap 1200w inverters and tie them together the phases of the ac signal will not match unless you are extremely lucky and that changes everytime you switch them on. Imagine the positive portion of the ac cycle of one inverter hitting the line at the same time as the negative cycle of the other inverter. Like putting a copper bar across your battery. Nice light show but the results could be extremely undesireable. If you need 2400 watts buy a 3000 watt inverter or get a generator.
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Old 25-03-2013, 04:04   #12
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Originally Posted by Lancerbye View Post
A lot of things are possible if the pockets are deep enough. In order to tie two or more inverters together, they need to have circuits called, tie-line controllers, that sync the multiple units to produce a common output. If you take two regular cheap 1200w inverters and tie them together the phases of the ac signal will not match unless you are extremely lucky and that changes everytime you switch them on. Imagine the positive portion of the ac cycle of one inverter hitting the line at the same time as the negative cycle of the other inverter. Like putting a copper bar across your battery. Nice light show but the results could be extremely undesireable. If you need 2400 watts buy a 3000 watt inverter or get a generator.
The technology is known as " N+1 invertors". Switching clock sync is the usual method. There are a number of invertors especially in the industrial area that are N +1. You will pay a premium.

Dave
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Old 25-03-2013, 13:49   #13
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Re: double the inverter double the wattage?

Just a question. Because of the inverter idle power use, would it be better to have multiple inverters sized for their different loads?
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Old 25-03-2013, 14:02   #14
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Re: double the inverter double the wattage?

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Just a question. Because of the inverter idle power use, would it be better to have multiple inverters sized for their different loads?
Most inverters that we use on our boats have a search function that sends out a pulse to see if there are any loads. You can set the threshold of this function. The inverter in search mode takes very little power but those pulses are enough to keep digital clocks on the microwave and DVD player accurate. Some folks buy a long, switched AC strip outlet and plug all their wall cubes into it for charging batteries of VHF handhelds, cell phones, cordless drills, etc.
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Old 25-03-2013, 14:09   #15
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Re: double the inverter double the wattage?

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The inverter in search mode takes very little power but those pulses are enough to keep digital clocks on the microwave and DVD player accurate.

aint ever seen that I must say

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