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Tibor Johancsik avatar image
Tibor Johancsik asked

Phoenix 12/375 early overload

Hi,

My Phoenix 12/375 is supposed to power my Grohe Blue Home water dispencer with max power of 280W. The Phoenix goes into overload almost immediately. I have a battery bank of 650Ah (fully charged). I have measured the consumption of the water dispencer with my Multiplus Compact + Cerbo and have shown max 150-160W.

Have checked the Phoenix with Victron connect, all parameters as standard.

Claiming 700 peak watt it looks strange.

Any idea?

Thx,

Tibor

Phoenix Inverter
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Alexandra avatar image Alexandra ♦ commented ·

@Tibor Johancs

It may be the power factor of the appliance, or the way it controls its power (i.e. triac based)

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Tibor Johancsik avatar image Tibor Johancsik Alexandra ♦ commented ·

Dear Alexandra,

As you have hinted, the water dispenser pump motor at startup consumes 3,5A AC for a few ms, than goes back to 0,5 A AC. The cooler consumes 0,1A AC. So I swapped my 12/375 for a 12/500, that can handle the 3,5A AC peak.

BUT: It means, I need to use a 70A DC fuse for those few ms when 10-15A DC would do for normal operation.

What do you think of using a buffer capacitor in parallel with the battery (like car HIFI folks with the sub bass)? When seldom needed (after drinking a glass of water) the inverter could drain the additional DC power from the capacitor, while in normal mode (pump already running / cooling) the power could come from the battery only - and charghing the capacitor. Thus I could avoid to double/tripple the fuse, and use a reasonable 20-30A intead of 70.

Thx,

Tibor

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Alexandra avatar image Alexandra ♦ Tibor Johancsik commented ·

@Tibor Johancsik

nice observation. Those momentary high draw amps are hard to catch.

What type of fuse do you have installed?

If it is not fast blow the one for the 375w should be ok.

375w ÷ 12v is 31.25A

500w ÷ 12v is 41.6A

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Tibor Johancsik avatar image Tibor Johancsik Alexandra ♦ commented ·
It is (will be) a marine 70A DC circuit braker. I need to go for the peak power drain of the 12/500. The momentary max of the load is 3,5x220 / 12 = 64.1, so I went for the next available, that is 70. Will install it tomorrow, today all day rain, and I do no like to play with 70A in rain.


What do you think about the capacitor as an idea, so I could go way below 70A ?

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Alexandra avatar image Alexandra ♦ Tibor Johancsik commented ·

Are you absolutely sure that your peak AC amps are 3.5A? I prefer sizing inverters with the peaks inside nominal rating.

Its not a terrible idea. I have seen the thing you are referring to. It makes some sense with a lead acid battery for a sudden draw.

That side is of things is really up to you. Are you planning on installing it before or after the breaker?

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2 Answers
Tibor Johancsik avatar image
Tibor Johancsik answered ·

Thanks, I have started to monitor the appliance amp usage. I have already seen unusual peaks. Unfortunately I have only a multimeter at hand here on the boat, so ‘storage’ is my eye … It is a cooler (around 0,6 A) + a motor (or alike) to build up the water pressure within the appliance for the soda water. When it starts, it makes peaks, that might bring the phoenix into overload. And when starting after overload again, and again until shutdown …

Funny Grohe stating max 280W …

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Tibor Johancsik avatar image
Tibor Johancsik answered ·

Hi,

The water dispencer pump motor at startap consumes 3,5A for a few ms, than goes back to 0,5 A. The cooler consumes 0,1A (both on 220). So I swapped my 12/375 for a 12/500, that can handle the 3,5A peak.

BUT: It means, I need to use a 70A fuse for those few ms when 10-15A would do for normal operation.

Did anyone use a buffer capacitor in parrallel with the battery (like car HIFI folks with the sub bass)? When seldom needed (after drinking a glass of water) the inverter could drain the additional power from the capacitor, while in normal mode (pump already running / cooling) the power could come from the battery - and charghing the capacitor. Thus I could avoid to double/tripple the fuse, and use a reasonable 20-30A intead of 70.

Thx,

Tibor

2 |3000

Up to 8 attachments (including images) can be used with a maximum of 190.8 MiB each and 286.6 MiB total.