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simonnhardy avatar image
simonnhardy asked

Dive Compressor

20230114-131233.jpg

We have a Victron Quottro 5kw and when connected to shore power it runs our Bauer Varius dive Compressor.

However when not on shore power it starts to turn the motor slowly but then goes into an overload error.

The motor is a 2hp 13A 230v motor however it does say 60hz but its always been OK on 50hz at home and as I say when on shore power.

The Cerbo GX says its drawing just over a 1000w when running ad you can see from the enclosed picture.

I thought it might be an aging capacitor fault so I fitted a new 700uf capacitor but it's still the same.

If I run the motor with the belt disconnected, so zero load it runs on both shore power and with no shore power from our 600ah Lifepo4 battery bank



MultiPlus Quattro Inverter Charger
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simonnhardy avatar image simonnhardy commented ·

Ive now fitted a new motor to the dive compressor with start and run capacitors, it still won’t start on the inverter.

I’ve looked for ESS in the Carbon GX but it says No ESS assistant found ?

I’m not sure if this would help but it might.

Currently I’m connected to shore power and if I put the Quattro so AC2 input is on and switch on the compressor it will start but if I immediately stop the compressor, make sure no pressure, then restart it won’t, just like it never will just on battery and inverter on.

I wouldn’t mind if it would always start on AC2 connected or Generator AC1 on.

Any help would be much apreciated.

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3 Answers
Sten avatar image
Sten answered ·

Hi


Your problem here is the starting surge from the compressor.

the start surge could be around 10 time the running power.

I think you need a softstarter. Somthing like this.

https://eu.mouser.com/ProductDetail/Carlo-Gavazzi/RGTS24160FV00?qs=xZ%2FP%252Ba9zWqY1dmukLigFyg%3D%3D

Whats important here is that it's a softstarter with a ramp up function.

it could also be a variable frequency drive with 1 phase output. they can be programmed with a ramp up time to.

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simonnhardy avatar image simonnhardy commented ·

Would it be better if I replaced the current motor with a twin capacitor motor. The curent motor has a centrifugal device inside ?

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Sten avatar image Sten simonnhardy commented ·
It will not make a big difference. You will stil have the start surge.


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mvas avatar image mvas commented ·

Let's hope this motor does not use 10 times the amps to start.

130 amps (starting) = 10 x 13 amps (running)
Quattro 5000 rated at 22 amps = 5000 watts / 230 volts
Quattro max surge amps = 44 amps but for only 1/2 second max!

Typically, the Soft Starter will reduce starting amps to 1/2 or 1/3 of original.
1/2 of 130 amps = 65 amps, will not work with a Quattro 5000
1/3 of 130 amps = 43 amps, will work with Quattro 5000, only if motor starts in 1/2 second

So, in that scenario the Soft Starter must ...
a) Reduce the start amps below 44 amps AND
b) keep the ramp / start time shorter than 1/2 second
But there is no margin of error.

What if ...
The actual start amps with this motor and a Soft Starter is only 33 amps?
Then the Quattro will operate, up to, 5 seconds.
But these types of motors must be "soft" started within 3 seconds.
So, I would configure / design for 33 amps Soft Start and 2 second ramp max.
The 33 amps keeps the Quattro 5000 happy
The 2 second ramp keeps the motor happy

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simonnhardy avatar image simonnhardy mvas commented ·
This doesn’t answer the origional question., and it doesn’t explain where ESS is configured using Cerbo GX as this maybee all that is required on either shore power or Generator running scenarios. Simon
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simonnhardy avatar image simonnhardy commented ·
Would you be able to give me the parts and a wiring diagram to sort this as im strugling to find anything other than the word soft starter and buy one. No one seems to know how it all fits together
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Alexandra avatar image
Alexandra answered ·

@simonnhardy

ESS is installed on the inverter with an assistant (requires a grid code) itself and is interactive with the GX.

A boat should not have ESS installed on it. So that is correct that you have no options there. Dont install it.

Is your unloading valve working ok?

If your DC (wiring and battery) is nicely oversized you should be able to start up the load easy easy.

What is your input current limit set at?

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simonnhardy avatar image simonnhardy commented ·
Hi. Input current is 16A. Ok NO ESS. I was asking about assistance so the Quattro 5000 uses either shore power or generator and the Lifepo4 to assist. With the original motor it would never start on shore or generator. I changed the motor for a more modern one that also has a separate start and run capacitor, the old motor only had one. Now if I switch on the compressor it will occasionally start but mostly just turns slowly then I get a fault, inverter overload. If it does start it will continue to run and build up pressure with no problem.
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kevgermany avatar image kevgermany ♦♦ simonnhardy commented ·
Look at adding a soft start unit between the compressor and the Quattro
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buddhafragt avatar image
buddhafragt answered ·

The motor is probably not reactive current compensated, it is best to plug a current meter (these cheap adapter plugs usually do it) that can measure reactive current in between and measure the reactive current component. Then install an appropriate compensation capacitor in parallel in the supply line. Calculation programs are available on the net.

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