Inverter wont work on boat?

[Spyro]

I purchased an inverter which works fine on the cigarette lighter outlet on my car but when I try to use it on the same type outlet which I have on the boat it doesn't put out any AC voltage. The outlet is OK as I use several items that req 12v DC and they work fine.
Any suggestions as to what could be wrong?

 

[Freebee]

polarity?

 

[Nuvalec]

Inverters take alot of current. Has it blown/tripped your fuse/breaker?

Tony.

 

[Shuggy]

A couple of things you might try. You don't mention whether any of its lights are coming on. If they're not, then you may not have compatible socket/plug on the boat. Check that there is a connection between both the +ve and -ve. Some sockets look the same as one you're used to, but have slightly different connector positions. Secondly, most inverters will cut out at a set voltage (from memory, around 10.5 or 11v?). If your battery voltage is a bit low, that may account for it.

 

[Birdseye]

cigarette lighter sockets are both variable in design and generally poor quality. First place to look is whether there is 12 v getting into the inverter.

 

[savageseadog]

Make sure the wiring to the socket is adequate. As the inverter powers up there will be a current surge which will drop the voltage, if the voltage drops too low the inverter will drop out. Some inverters are specifically designed to switch off on low voltage to protect the batteries some just do it anyway.

 

[Spyro]

Thanks for all answers. Polarity is correct. fuses are not blowing or tripping, current is getting to the inverter ok as the plug which goes into the socket has a led to show it is receiving power ok. It's only a 150W inverter so current draw shouldn't be to much. It may be due to the voltage drop which I was aware of so I tried it with the engine running. but still the same. Next time I'll get a meter onto it and see what current it is drawing.

 

[Talbot]

[ QUOTE ]
It's only a 150W inverter so current draw shouldn't be to much

[/ QUOTE ]

if you are drawing 150w from the inverter, then the chances are good that you are drawing at least 12.5 amps from your 12v socket.

 

[Spyro]

Talbot
A 150 watts is the max power output rating of the inverter. I know that 150 watts will draw 12.5 amps (I=P/V). I was referring to current draw when nothing is plugged into the inverter which will be much lower.

 

[Nuvalec]

Yeah - when an inverter initially switches on, there is a current surge. If you've got bellwire feeding that socket, you will get a voltage drop wether there is anything plugged in or not.

Tony.

 

[yoda]

Is the voltage on the boat too high. Saw a similar device cutting out last week when voltage was geting too far above 12 volts.

Yoda

 

[Nuvalec]

This looks like one of those silly little jobs where someone knowledgeable in electrical systems needs to have a 5 minute look at it.

Don't ask me, you're in the Clyde.

Tony.

 

[Rowana]

I would suggest it's due to voltage drop.

Your inverter will draw a fair old current, and will pull the voltage at the socket down so that it doesn't work. The power loss in a cable varies as the SQUARE of the current, so the more you draw, the MUCH greater the loss.

2 solutions -
1. Beefier cables.
2. Move the socket so that there is shorter cable

You could say solution 3 - Short, beefy cables. This would be my solution.

 

[Birdseye]

easy to test. jury rig it direct to the battery and see what happens.

you have got the socket polarity the right way round havent you?