No 240v!!!! Help.

[Amphibian Man]

Hi folks,

I am in a pickle. My inverter has decided not to work. The engine runs fine. The 12 v is working. But the battery low light on the inverter is red and I have no 240v. I am new to canal life so seem to be asking and taking more than I give on this forum. If anyone can help I would be extremely grateful. It's a Victron Phoenix combi  12 1600 75.

[BWM]

4 minutes ago, Amphibian Man said:

Hi folks,

I am in a pickle. My inverter has decided not to work. The engine runs fine. The 12 v is working. But the battery low light on the inverter is red and I have no 240v. I am new to canal life so seem to be asking and taking more than I give on this forum. If anyone can help I would be extremely grateful. It's a Victron Phoenix combi  12 1600 75.

Check the connections at the batteries and inverter, and the voltage available from the batteries as the inverter will cut out below a certain voltage. 

 Also worth checking any isolation switches as they often fail internally and cause all sorts of issues, particularly the cheap ones.

Edited March 31, 2023 by BWM

[MtB]

5 minutes ago, Amphibian Man said:

But the battery low light on the inverter is red and I have no 240v.

 

 

Surely the problem is self-explanatory. Your domestic batteries are flat. 

 

 

Try running the engine at say half speed, i.e. a good bit faster than tickover.  Does the "Battery Low" light still come on? 

[Amphibian Man]

Thanks. The 12v lights etc work so I thought the batteries are OK. Do they not get charged up while the engine is running?

Hi MtB,

I ran the engine for a couple of hours about 1500 rpm. But still got the red light.

[David Mack]

 

7 minutes ago, Amphibian Man said:

Hi MtB,

I ran the engine for a couple of hours about 1500 rpm. But still got the red light

Yes. But have you tried the inverter while the engine is running? If the charging system is working that will raise the battery voltage sufficiently for the inverter to work, even if the batteries are flat (or knackered).

[Amphibian Man]

Hi David Mack,

I am sure the inverter was switched on while the engine was running.

[MtB]

32 minutes ago, David Mack said:

 

Yes. But have you tried the inverter while the engine is running? If the charging system is working that will raise the battery voltage sufficiently for the inverter to work, even if the batteries are flat (or knackered).

 

^^^ This ^^^

 

We are asking you to check if that red "Battery Low" light on the inverter stays ON or if it goes OFF, while the engine is running, well above tick-over.

 

Over to you...

 

 

... or better, do you have a digital multi-meter and know how to use it? 

 

 

 

 

 

 

 

 

 

Edited March 31, 2023 by MtB
Clarify.

[Tony Brooks]

34 minutes ago, Amphibian Man said:

Thanks. The 12v lights etc work so I thought the batteries are OK. Do they not get charged up while the engine is running?

 

You are just the latest person to think that. You don't say what 240V loads you have on, but an inverter will draw far more currant than is needed at 240V. That high current from the batteries in effect causes the battery voltage to drop. Add to that the fact that a lot of the 12V equipment will still work at 10V or less and you get an easy mistake to make. Does the domestic water pump take longer to turn off than it does with the engine running?

[Amphibian Man]

Hi MtB,

The red light stays on while the engine is running. I have a dmm and can use it.

 

Hi Tony Brooks,

The 240v socket won't even charge my phone with engine running on high revs

 

[PCSB]

Its worth checking any isolation switches between the battery positive supply and the inverter. I did some work recently on my boat and left the isolator off when I put the inverter on and I got the red low voltage warning, went when I realised I had been a numpty and switched the isolator on.

[nicknorman]

6 minutes ago, Amphibian Man said:

Hi MtB,

The red light stays on while the engine is running. I have a dmm and can use it.

 

Hi Tony Brooks,

The 240v socket won't even charge my phone with engine running on high revs

 

If you have a DMM then check the 12v dc input voltage to the inverter. If it is well up (above 12v) then sounds like the inverter is faulty. If it is below 12v then probably the 12v system voltage is too low. Lights etc will continue to work long after there is insufficient voltage to operate the inverter.

 

Also check the 12v system voltage when the engine is running at a fast tickover or a bit faster. It should be up over 14v but if it’s not, perhaps the problem is an alternator fault.

 

If you mostly need the inverter to charge your phone, do get a 12v charger (the kind of thing your use in a car) because converting 12v up to mains ac voltage and then back to 5v for the phone, is highly inefficient. As you will discover, managing electrical power is a “big deal” for a live aboard off grid.

 

Edited March 31, 2023 by nicknorman

[MtB]

4 minutes ago, Amphibian Man said:

The red light stays on while the engine is running. I have a dmm and can use it.

 

 

Ok great, thanks! 

 

Well not so great as I was hoping it would go out...

 

Next step, expose the 12V cable connections on the inverter and measure the voltage across them, while the red light is showing. 

 

What do you get, to the nearest 0.1V? 

 

 

[Tony Brooks]

2 minutes ago, Amphibian Man said:

Hi MtB,

The red light stays on while the engine is running. I have a dmm and can use it.

 

Hi Tony Brooks,

The 240v socket won't even charge my phone with engine running on high revs

 

 

They would not because the inverter seems to have shut down on low volts, but why you don't use a 12V "car" lead to charge the phone is beyond me. Going from 12V to 240V and back to about 5V wastes electricity at each set up and down.

 

The engine does not just have to be running, but at 1200 rpm or more when you look at the inverter red light.

 

I suggest that you put the Multimeter set to volts across the domestic battery bank and note the reading, start the engine and rev at 1200 rpm or more  while watching the meter, note if the meter jumps up and to what level. If it does jump up, keep the engine running for a couple of hors and note what the meter then reads. Report the three readings back to the forum.

 

 

3 minutes ago, nicknorman said:

Also check the 12v system voltage when the engine is running at a fast tickover or a bit faster. It should be up over 14v but if it’s not, perhaps the problem is an alternator fault.

 

Not totally correct, as I am sure Nick knows. The higher the charging current, the lower the charging voltage. With very flat batteries, it could be as low as 13.5 volts or less.

[Amphibian Man]

Thanks everyone. I am really grateful and encouraged by your input. I will try a few suggestions and get back to the forum ASAP.

Cheers.

[ronnietucker]

On 31/03/2023 at 17:14, BWM said:

Also worth checking any isolation switches as they often fail internally and cause all sorts of issues, particularly the cheap ones.

^--- this

My isolation switch had a problem which gave me no 240v. Needed to get the switch replaced.