Thread: Question For A Sparkie. Inverter Earth.

Hi Dave and just how big is your inverter, because there may be a far safer way to set it and your caravan up.

Do tell.
Mine is 2000W.

300 watt. One of these.

SI 300 220V Morningstar Suresine 300 Watt Solar Pure Sine Inverter 12V 220V | eBay

depends on the inverter.....

some have an inbuilt RCD setup and an earthing stud. if thats the case simply join the mains earth point on the inverter (some its just the casing or a wing nut on the casing) to the earthing on the caravan and then plug into it as per normal.

before you go ahead and try setting it up read the manual some inverters do not like having the -ve DC supply connected to the body of the inverter which is the earth for the AC power output. to check this with the inverter off and de energised ( short the DC side and plug a light into the AC socket with the inverter on) using a multimeter probe from the earth pin on the AC to the body of the inverter then to the -ve battery lead (after you unshort them)


unless the inverter is setup with a junction socket for direct wiring for mains it may not be suited for what you need. One method I have seen for getting around all of the problems is to put the inverter on an insulated board, go from your normal power inlet into a plug in RCD and plug that RCD into the inverter.

Hi Dave, my suggestion is more for inverters of 800w or higher, mainly because of the cost.

I supply RVDs which add the greatest possible safety level to inverters ( and generators ) and remove the the earth from the circuit, making it floating circuit.

BUT, the 8 amp RVDs are around the $160 mark.

Go with dave's ( Blknight's ) suggestions.

Originally Posted by d2dave

300 watt. One of these.

SI 300 220V Morningstar Suresine 300 Watt Solar Pure Sine Inverter 12V 220V | eBay

heres the manual

[ame]http://www.morningstarcorp.com/wp-content/uploads/2014/01/MS-ZMAN-SI-EN-A_ETL.pdf[/ame]

that inverter has a dedicated earth pin. it also has an isolated output and requires that you tie the neutral to earth to identify from neutral from active

it does not advertise having inbuilt RCD only full short and overload protection.

there is no warning about dc earth being the same as mains earth.

its got an auto cut feature in it it will give you 3 auto restarts and then lock out its output off and it then requires a manual reset. be careful what you have plugged into it when you fire it up if you have a compressor or high current load.

What were you planning on running from the inverter.? you might be better off getting an inverter that has normal australian pin mains sockets and mounting it where you can plug into it when you need to.

Originally Posted by Blknight.aus

What were you planning on running from the inverter.? you might be better off getting an inverter that has normal australian pin mains sockets and mounting it where you can plug into it when you need to.

Lights, and lap top. I went for this unit as it goes to sleep when there is no load under 8 watts.
This means I can leave it on indefinitely when on holidays.

Ok. Here are two pages from the manual.

In this pic it says to use 25mm cable for earth ground. This is surely a miss print? This would be my jumper leads.

Why is the earth on the DC side? Why does the earth need to be bigger than the DC in cables?

With AC in house wiring, the earth can be smaller than the active and neutral.



In the next pic what do I do with earth where I have indicated?

It also says to run a link from neutral to earth. Why don't they just do this internally?

It also does not show any earth connection into the wiring.