Inverter Help

[DaveAdele]

Hi looking for help on my next project. I'm wanting to fit a victron phoenix 1600w inverter and i want it to be connected to a automatic relay whereupon it will switch my 240 sockets over from mains (if connected) to the leisure batteries via the inverter. I have space next to it near my batteries for this or even a larger one. When speaking to some motorhome fitters they seem reluctant to fit them, quoting problems with fitting the relays.
My questions are:

1. The maximum use at any one time would be our 600w microwave for 10 to 15 mins most days or if if totally desperate our Tassimo Coffee Machine 1300w (can manage without this). Would the victron phoenix 1600w inverter be good enough or would i need more power?
2. Would fitting the auto relays be a big problem?
3. I know using a inverters this way is a hit on your batteries but would they cripple my two 95a leisure batteries?
4. I rate myself as a competent person to do this, certainly not a expert but is this project doable for a good DIY'er or should i look for professional fit?

Thanks in advance for your help


David

 

[DaveAdele]

Thanks

Thank you. Ok so i take out the coffee machine out and just switch on the inverter manually and increase the inverter to 2000w and just use it solely for the 10-15 mins microwave use would this then still be doable for me to fit?

 

[mistericeman]

I have a spare Waeco inverter that has smart bypass
Along with its mains priority circuit which smoothly switches over to mains as soon as its available in your caravan or motorhome and its soft start

That said we run a 3000w inverter to run microwave oven/toaster /kettle /slow cooker etc
as we don't have gas on board...
2 X 100w solar panels on the roof and a Durite voltage sensing split charge relay keep the 3 x 100ah leisure batteries charged.

 

[trevskoda]

He may get away with the m/wave if only to heat something for about 3/5 mins but as far as doing a big dinner forget it,batts will not last and as others have said you would have to drive 200/300 miles to recharge,as for 200w of solar doing that,never in a month of sundays.:lol-053:

 

[Admin]

Hi looking for help on my next project. I'm wanting to fit a victron phoenix 1600w inverter and i want it to be connected to a automatic relay whereupon it will switch my 240 sockets over from mains (if connected) to the leisure batteries via the inverter. I have space next to it near my batteries for this or even a larger one. When speaking to some motorhome fitters they seem reluctant to fit them, quoting problems with fitting the relays.
My questions are:

1. The maximum use at any one time would be our 600w microwave for 10 to 15 mins most days or if if totally desperate our Tassimo Coffee Machine 1300w (can manage without this). Would the victron phoenix 1600w inverter be good enough or would i need more power?
2. Would fitting the auto relays be a big problem?
3. I know using a inverters this way is a hit on your batteries but would they cripple my two 95a leisure batteries?
4. I rate myself as a competent person to do this, certainly not a expert but is this project doable for a good DIY'er or should i look for professional fit?

Thanks in advance for your help


David

1. The maximum use at any one time would be our 600w microwave for 10 to 15 mins most days or if if totally desperate our Tassimo Coffee Machine 1300w (can manage without this). Would the victron phoenix 1600w inverter be good enough or would i need more power?

A Victron Pheonix 12 / 1600 is actual 1300w continuous. It will run at 3000w for a short time so there are no problems with high startup surges. I currently have a Multiplus 12 / 1600 / 70 which runs my 600w microwave and my 1400w Nespresso coffee maker. (Tassimo is yak).

You can find a Multiplus Compact for a similar price to a Pheonix, but the Multi Plus is awesome! It is a pass-through inverter so no relay. It can assist and correct the mains supply. It can feed back to the electric grid. And it is a high power multi-stage charger. Personally, I would go for a 12 / 2000.
2. Would fitting the auto relays be a big problem?

I would not bother just fit a MultiPlus.
3. I know using a inverters this way is a hit on your batteries but would they cripple my two 95a leisure batteries?

Bit of maths.

2 x 95Ah (c20) = 190Ah, 60% usable = 114Ah.

600watt (cooking power) microwave is about 1000 watts mains load, 1000w / 12v + correction for 92% efficiency = about 90A drain.

15 minutes micropower = 22.5Ah out of your theoretical 114Ah.

But as your load would drain your batteries in just over an hour I think you would only achieve about 70Ah(>c5) per battery 2 * 70Ah = 140Ah, 60% usable = 84Ah.
4. I rate myself as a competent person to do this, certainly not a expert but is this project doable for a good DIY'er or should i look for professional fit?
1) Many motorhomes only have small cables between the batteries. You will have to upgrade the cables linking your batteries to larger cable than that supplying the inverter to spread even load across the batteries and allow capacity for other loads. You will also need to take the positive from battery 1 and the negative from battery 2.

2) The inverter 230v input has to be connected to the MCB that is supplying your sockets, then the 230v output to the cable(s) you have removed from the MCB.

3) Install a remote switch if you cannot reach the inverter to switch on and off.

4) If you do fit a MultiPlus then you need to disable the motor homes on board charger, on many units this is just a switch or plug, but on others you mant need to isolate it.

 

[Tezza33]

We use a 500W microwave with a Sterling 1600W inverter but we only use it for warming things up or reheating, never have a problem even in Winter with 250W solar, a Sterling 60W Battery to Battery charger and 225A Trojan batteries, we don't use a microwave for cooking complete meals at home so we wouldn't in the van, we use a coffee maker at home but quite happy to make proper coffee on the hob

 

[mistericeman]

Seems an awful lot of expense and hassle to avoid having gas. Why not just fit a gas tank?

No hassle and Didnt want any gas on board.... simples

Works perfectly for us.... never needed hook up since we built it...
Even over Xmas/New year break.

 

[Tezza33]

No hassle and Didnt want any gas on board.... simples

Works perfectly for us.... never needed hook up since we built it...
Even over Xmas/New year break.

Each to their own, if it works for you then others opinions don't matter

 

[Wooie1958]

Each to their own, if it works for you then others opinions don't matter

Seconded :wave:

 

[Deleted member 9849]

I have a spare Waeco inverter that has smart bypass
Along with its mains priority circuit which smoothly switches over to mains as soon as its available in your caravan or motorhome and its soft start

That said we run a 3000w inverter to run microwave oven/toaster /kettle /slow cooker etc
as we don't have gas on board...
2 X 100w solar panels on the roof and a Durite voltage sensing split charge relay keep the 3 x 100ah leisure batteries charged.

Do you use the van in winter and if so what type of heating do you have?

 

[mistericeman]

Do you use the van in winter and if so what type of heating do you have?

Yes we do... heating is via a eberspacher d2

 

[yeoblade]

Using my 700w microwave on a 2k inverter, (3k peak) the clamp-on meter showed a 70 amps Dc current draw to the inverter.
With 2 x 110 ah new batteries it worked fine, for a while, but must have knackered the batts as they no longer hold charge so I have just renewed them at only 2 yrs. old. Van has 250w Solar.
I am longer going to use too heavy a load on the inverter with my new batts, The genny :scared::lol-053: will be employed for microwaving, cheaper than replacing the batteries again.

 

[Robmac]

You would be very lucky to be able to run a 600 watt microwave on a 1600 watt inverter. It will probably draw more than 2000 watts on startup.

I have to disagree with that, as I know somebody who does exactly that, (actually, his is a 1500w inverter, I know, because I gave it him) and I have seen it in action.

I am not sure about the power of his microwave though, but I would say at least 600w as it is a domestic model rather than designed for a Motorhome. He is on this forum so he may comment, but otherwise I will ask him next time I talk to him.

 

[trevskoda]

I have to disagree with that, as I know somebody who does exactly that, (actually, his is a 1500w inverter, I know, because I gave it him) and I have seen it in action.

I am not sure about the power of his microwave though, but I would say at least 600w as it is a domestic model rather than designed for a Motorhome. He is on this forum so he may comment, but otherwise I will ask him next time I talk to him.

600 w is the cooking power,if you look at the back of most the plate will give used power which is norm just over twice the cooking power,then there is the surge on start up which can be a further one third of that again.
So as most state a 650w m/wave will at around 1300w draw will run on a 1500w inverter with a higher surge rating.

 

[trevskoda]

We use a 500W microwave with a Sterling 1600W inverter but we only use it for warming things up or reheating, never have a problem even in Winter with 250W solar, a Sterling 60W Battery to Battery charger and 225A Trojan batteries, we don't use a microwave for cooking complete meals at home so we wouldn't in the van, we use a coffee maker at home but quite happy to make proper coffee on the hobView attachment 57451

I have been using a m/wave 90% at home for over 40 years for all cooking and only of late bought a table top oven/grill.
Big old fashioned ovens are from the stone age,next we will be lighting big fires and putting big cooking pots on top.:lol-053:

 

[Admin]

I have a QT1 600w microwave and its maximum mains wattage is 1200w. On modern microwaves doubling the cooking power is a good rule of thumb.

 

[Deleted member 43466]

hi
ive got a cheap silvercrest 700w microwave from Lidl its got adjustable
cooking power. I have just heated something up with a Xantrex 1000 pure
sine wave inverter. i started on 400w and turned it up to 580w it ran ok.

 

[yeoblade]

When a microwave is used on less than max power setting I thought they zapped it with rated power, then stopped the power ie. alternating an on off cycle of power to give an overall reduced power, o rare there different types?

 

[winks]

Seconded :wave:

Too right Mr Woo.

And here's a couple of pictures of our inverter installation because I can't get the PM system to attach pictures.

Phew! at last. I think the ends slide off the remote to reveal fixing holes.
And the inverter is under the bench seat with a dedicated double socket fitted on the end facing the hab door.

Cheers

H

 

[mistericeman]

Too right Mr Woo.

And here's a couple of pictures of our inverter installation because I can't get the PM system to attach pictures.

View attachment 57470 Phew! at last. I think the ends slide off the remote to reveal fixing holes.
View attachment 57471 And the inverter is under the bench seat with a dedicated double socket fitted on the end facing the hab door.

Cheers

H

Remote activation is a must for a hard wired inverter... especially if it's fitted like ours in an out of the way spot.