Ghurd controller with Inverter

[paulrogers6]

Hi Guys

I have a GHurd controller configured as an LVD which I'm wiring up to switch an inverter on and off.  Glen kindly provided me with some schematics etc to do this.  The schematics show theLVD switching  a 12v relay in parallel across the inverter's toggle switch.

My question is:

Is there any reason the relay/lvd couldn't be wired in series with the inverter's switch?  This would allow me to switch the inverter off completely (using the toggle switch) if I needed to.  I can see no reason not to make this mod but would like to check first.

Many thanks

Paul

[TomW]

Paul;

I would do it if I wanted that option.

I see no reason not to as it will see the same loads it would across the switch.

Just my opinion.

Tom

[paulrogers6]

Tom

Thanks for the reply

I couldn't see any harm in it but thought I'd check

Again, many thanks

Paul

[dave ames]

hey paul,

i'd be real tempted to do both..if your follow ghurds sketch AND then put a toggle in series

before or after the parallel piggyback.. it would let you turn the inverter on with the inverter

switch when the ghurdâ„¢ is off and with the added series toggle we can turn the inverter off

when the ghurdâ„¢ is on.

just another opinion/option.

dave

[TomW]

hey paul,

i'd be real tempted to do both..if your follow ghurds sketch AND then put a toggle in series

before or after the parallel piggyback.. it would let you turn the inverter on with the inverter

switch when the ghurdâ„¢ is off and with the added series toggle we can turn the inverter off

when the ghurdâ„¢ is on.

just another opinion/option.

dave

Certainly another option for if / when the GHurd device bails or you want to manually control it.

Always multiple methods to defur a feline.

Tom.

[ghurd]

I have been away.

"Is there any reason the relay/lvd couldn't be wired in series with the inverter's switch?"
I will take that as a typo, and you mean the main power wires feeding the inverter...

Problem-
Input capacitors.
They cause the sparks when the power cable is connected to the battery.
That's a lot of amps. 
Controlling amps is Expensive.

Example-
A small 400W inverter.  Probably has an 800W surge.
800W / 12V, throw in inefficiencies, with a load that is connected, and empty input caps...
That puts the INVERTER'S surge current up past 100A easy enough, and fairly sustained (as far as semiconductors go).
That's expensive.

And semiconductor have losses, which add to inefficiency.

Next question will probably be about relays.
It would need a pretty serious relay.
Serious relays use serious amps in the coils.  Which would be a good idea to do away with.


If it was not a typo, and the toggle switch is in series with the relay coil, then no problem at all.
I may have posted this for "Snake" a while ago.

[paulrogers6]

Hi guys

many thanks for the replies.

Glen - you're diagram is similiar to the one you sent me previously (no led's in that one).  In the diagram you show the relay in parallel with the inverter's switch.  I was asking if it was ok to change this so the relay was in series with the switch.  Sorry, I did't make myself clearer.

Thanks again for all the answers.

All the best

Paul

[ghurd]

I can not say if that is a good idea for your inverter.

I suppose it would be fine.

I can not see any advantage to the relay being in series with the switch.

The disadvantage is if the LVD shuts down the inverter with the relay in series, then would need a switch in parallel with the relay contacts to turn it on in an emergency.

With the relay in parallel with the switch, can turn the inverter on in an emergency by turning the factory inverter switch to On.
G-

[paulrogers6]

Hi G

I'm in the process of setting my system up and currently there's not enough PV, wind etc to keep the batteries topped up (I've been supplementing things with a charger).  I was just thinking it'd be nice to have the option to manually switch the inverter off and have the peace of mind that nothing was draining the batteries.  With the switch in parallel this isn't possible.

It's probably me being overly cautious.  I should just trust the LVD to switch the inverter off if the voltage drops too low ( as it's designed to do).  Or do what dave suggested and do both ;-)

Thanks for the reply.

Regards

Paul

[ghurd]

The sketch above shows a manual inverter shutdown switch in series with the relay coil.

6 of 1, half dozen of the other?
G-

[paulrogers6]

Hi G

Wired inverter as shown.  All works a treat now.

Many thanks for all your help.

P