Inverter Installation - fuse - isolation switch?

UFO

Full Member
Posts
565
Likes
721
Just about to order a Renology Pure Sine Wave Inverter.

It's main use will be to charge a laptop. The laptop PSU is a Delta ADP-180MB K output 19.5v DC at 9.23a = 180w. With an input of 240v AC the current should be 0.75A plus a bit for losses in the PSU, say 1A with a good margin.

Using the 'Calculator | AC to DC Amperage Conversion Calculator using a DC to AC Power Inverter' at https://w ww.batterystuff.com/kb/tools/dc-to-ac-amperage-conversion-run-through-an-inverter.html

Drawing 1A from the inverter it will draw 22A from the battery.

I will buy the 1000W inverter to give some future capacity but I can't think of anything else that we might need to use the inverter for. 1000W would provide 4.16A which would draw 92A from the battery. Surge power is 2000W which means 180A from the battery.

I will wire the inverter direct to the battery through the 100A battery monitor shunt. Cable run will be very short.

Some questions
1) Is a fuse needed between the inverter and the battery or is this covered by a fuse in the inverter? Fuse would need to be 200A to allow for the 2000W surge cabaility of the inverter.
2) Is an isolation switch needed between the inverter and the battery or does the inverter on/off switch break the connection between the inverter and the battery? When the inverter is not in use, and is switched off, I don't want it drawing current from the battery. The inverter specifications quote a 'no load current draw of <1A'. Switch would need to be 200A for the reasons stated above.

thank you
 
Just about to order a Renology Pure Sine Wave Inverter.

It's main use will be to charge a laptop. The laptop PSU is a Delta ADP-180MB K output 19.5v DC at 9.23a = 180w. With an input of 240v AC the current should be 0.75A plus a bit for losses in the PSU, say 1A with a good margin.

Using the 'Calculator | AC to DC Amperage Conversion Calculator using a DC to AC Power Inverter' at https://w ww.batterystuff.com/kb/tools/dc-to-ac-amperage-conversion-run-through-an-inverter.html

Drawing 1A from the inverter it will draw 22A from the battery.

I will buy the 1000W inverter to give some future capacity but I can't think of anything else that we might need to use the inverter for. 1000W would provide 4.16A which would draw 92A from the battery. Surge power is 2000W which means 180A from the battery.

I will wire the inverter direct to the battery through the 100A battery monitor shunt. Cable run will be very short.

Some questions
1) Is a fuse needed between the inverter and the battery or is this covered by a fuse in the inverter? Fuse would need to be 200A to allow for the 2000W surge cabaility of the inverter.
The Fuse in the Inverter is there to protect the Inverter. You should add a fuse close to the battery to protect the cable.
2) Is an isolation switch needed between the inverter and the battery or does the inverter on/off switch break the connection between the inverter and the battery? When the inverter is not in use, and is switched off, I don't want it drawing current from the battery. The inverter specifications quote a 'no load current draw of <1A'. Switch would need to be 200A for the reasons stated above.

thank you
No Load current draw quoted is when the inverter is switched on but nothing is plugged in on the AC side.
If you can switch it off on the inverter itself, then the inverter overhead will be 0A, or so close to it such that is doesn't matter. If you can easily access the inverter switch, I would just use that I think.

If you exceed the 100A rating on the SOC Battery Monitor, then it probably won't matter as will be just very short durations, but your SOC value might start to become inaccurate.
 
I,ve charged/used my HP laptop with a 12v to 19v lead designed for this for several yrs successfully. Here's a similar one It'll save you a lot of money and work
 
Last edited:
With an input of 240v AC

You're showing your age !

Since 1994 in the UK, mains electricity is currently required by law to be delivered at 230 Volts,
within a tolerance of +10% / –6%, that is, within the range 253 Volts to 216.2 Volts.
The value of 230 Volts is said to be the ‘nominal voltage’

BTW we changed to a decimal currency back in 1971.
 
You're showing your age !

Since 1994 in the UK, mains electricity is currently required by law to be delivered at 230 Volts,
within a tolerance of +10% / –6%, that is, within the range 253 Volts to 216.2 Volts.
The value of 230 Volts is said to be the ‘nominal voltage’

BTW we changed to a decimal currency back in 1971.
mine dropped below 240V once in the last year (and that was down to 239V :) )

in reality, the UK supply is still 240V. the European harmonisation between 220V continental and 240V UK was really to do with making sure appliances would work in the harmonised "230V" range, not to have the actual supply harmomised.
 
I,ve charged/used my HP laptop with a 12v to 19v lead designed for this for several yrs successfully. Here's a similar one It'll save you a lot of money and work
I had one of these lying around, used with previous laptop, so I tried it. It did not last long as drawing 180W from something rated at 65W = melted plastic.
I use a 150w modified sine plug in inverter to charge phones, tablet and ebike with no problems. Only high tech bit was to provide a cig outlet nearer to battery.
I have a 150W inverter, not modified sine or pure sine, but it can't handle 180W.

So I have decided to go large, but not too large, at 1000W. Installation is straightforward as it can be mounted close to the battery box. This will cover current needs with a lot to spare but who knows what might be needed in the future.
 
You're showing your age !

Since 1994 in the UK, mains electricity is currently required by law to be delivered at 230 Volts,
within a tolerance of +10% / –6%, that is, within the range 253 Volts to 216.2 Volts.
The value of 230 Volts is said to be the ‘nominal voltage’

Always high in Bristol too.

Voltage.jpg
 
Since 1994 in the UK, mains electricity is currently required by law to be delivered at 230 Volts,
within a tolerance of +10% / –6%, that is, within the range 253 Volts to 216.2 Volts.
The value of 230 Volts is said to be the ‘nominal voltage’
Like Wildebus my domestic supply has been 240v volts, give or take a volt or two, everytime I have measured it over the years.

Granted the inverter output will be '230VAC±10' according to the Renology specs for this inverter.
 
Yes, makes sense. The supplied cable is 20mm² / 5 AWG, so good for 135A, length 600mm.

Given my intended use and the BM shunt being rated at 100A. I will go with a 100A fuse, like this https://www.ebay.co.uk/itm/124964754964?var=426035753284 which would suit the lugs on the cable supplied.

There are basic in-line maxi-fuse holders but needs to accomodate the 20mm² cable terminations.
Have you bought that already? TBH I have not had much luck with the ANL Fuse Holders. They tend to be made from a plastic that distorts when they get hot. (had about 4 or 5 different ANL holders and they have all done it :( ). The Mega Fuse Holders tend to be much more reliable I've found.
 
  • Like
Reactions: UFO
246v here ATM, often pushes the upper limit of 253v. Don't think I've ever seen it close to 230v.
 
Have you bought that already? TBH I have not had much luck with the ANL Fuse Holders. They tend to be made from a plastic that distorts when they get hot. (had about 4 or 5 different ANL holders and they have all done it :( ). The Mega Fuse Holders tend to be much more reliable I've found.
Great advice. The Mega Fuse Holder will be just the job and easy to incorporate into the current set-up. Renology recommed a 125A fuse but I will fit 100A as this will provide more protection for the cables while still being within spec for the maximum inverter current draw. I will now order all the bits and get it installed ready for our next trip.

thank you
 
Last edited:
Great advice. The Mega Fuse Holder will be just the job and easy to incorporate into the current set-up. Renology recommed a 125A fuse. I will now order all the bits and get it installed ready for our next trip.

thank you
it is a great shame really. There are some very nice ANL Holders available, one of which was ideal for my purpose but they all suffered the same fate :( I have a few which are still perfect but cannot sell them with a clear conscience so stuck with them!
 
Inverter now installed and working. There is an earth terminal on the inverter. Where to connect to this to? The vehicle and leisure batteries have the negative connected to the vehicle body. Won't connecting the inverter earth to the vehicle body be the same as connecing the earth to the battery negative?

I understand that there are designated earth points, it's a 2009 Fiat Ducato panel van conversion, and I need an earth point nearside rear.

Look forward to the clarification. Thanks.
 
Inverter now installed and working. There is an earth terminal on the inverter. Where to connect to this to? The vehicle and leisure batteries have the negative connected to the vehicle body. Won't connecting the inverter earth to the vehicle body be the same as connecing the earth to the battery negative?

I understand that there are designated earth points, it's a 2009 Fiat Ducato panel van conversion, and I need an earth point nearside rear.

Look forward to the clarification. Thanks.
i connect to the same ground.

TBH I don't know if needed, but follow the install instructions for each inverter as there "must" be a reason :)
 
i connect to the same ground.

TBH I don't know if needed, but follow the install instructions for each inverter as there "must" be a reason :)
I thought it was in USA where they are supposed to connect inverter earth to chassis? We have probably had this discussion a few times but the sieve that it my memory doesn’t recall. I know I don’t connect inverter earth
 
I have watched utube vids on earthing inverters, most say not required as you cannot get a shock from them, others say use a ground plate under a wheel, mine has no earth, but i do have a second one not fitted and it has an earth wire, I would just wire to van earth/battery neg, tyres have carbon in the construction and any earth will find its way down.
Just wondering what you intend to use it for, hob m wave etc.
 
Yes, can't see the need for an inverter earth, so unless someone can explain the science behind having it earthed I won't bother.
i connect to the same ground.
Same as what? Battery negative vehicle body?
Just wondering what you intend to use it for, hob m wave etc.
It's1000W and will be used for laptop and camera battery charging, for which the inverter is more than enough but I have gone through a number of smaller / cheaper inverters so I have gone a bit over-the-top for this one.
 

Users who viewed this discussion (Total:0)

Back
Top