Just a terminology confirmation, I think.
Could some generous person confirm that this Relay only "switches on" when the power is connected ?
I am assuming "Normal Open" means that the switched circuit is disconnected when the 24 volt input is not being supplied.
Many thanks for any advice.

 

confirm that this Relay only "switches on" when the power is connected

That is correct.
1NO means there is one relay contact that is normally open when no coil power is applied.

 

How much current do you need to switch?? AND the big question is how reliable does this application need to be??
Notice that while the style implies a high current rating the terminal size does not.

 

Notice that while the style implies a high current rating the terminal size does not.

The contact terminal is an M5 5mm screw which is equivalent to about 4 AWG.
They appear to be copper screws so should be able to carry 80A without a problem.

 

How much current do you need to switch?? AND the big question is how reliable does this application need to be??
Notice that while the style implies a high current rating the terminal size does not.

Many thanks for the contribution.
The amount of current in the switched circuit is just 12v battery charging levels.
The application requires reliability, but only in a low usage (say 6 times a year) environment.

I'd be interested in more detail about the apparent "high current rating". Perhaps they are using a cheap industrial strength coil in a consumer circuit product ?

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Detailed Explanation
The intention is to have a three position switch that changes a two 12v battery setup, from 12 to 24 volt input/output.

When the Series (24 v) circuit is cut in Position 1 , the switch goes to Neutral. Then, when the switch is turned to the Position 3 , a 12 volt source closes two relays , to create a 12v Parallel output.

The intention is to only charge the Batteries in 12v Parallel mode, while the 24v series configuration supplies a 24V, 30 amp (500 watt) electric motor.

At the moment, the user has to remember to cut the 24 volt switch before activating the two 12 volt switches, which could be problematic. Simple schematic below.

 

The amount of current in the switched circuit is just 12v battery charging levels.

If it's just charging current you are switching, then that relay seems to be overkill, as a standard, lower current relay should be adequate.

 

If it's just charging current you are switching, then that relay seems to be overkill, as a standard, lower current relay should be adequate.

Being really new, if you could suggest some examples, with links perhaps, that would be appreciated. Cheers.

 

Being really new, if you could suggest some examples, with links perhaps, that would be appreciated. Cheers.

What's the maximum charging current?

Do you need the relay coil to be 24Vdc or can it be 12Vdc?

 

What's the maximum charging current?

Do you need the relay coil to be 24Vdc or can it be 12Vdc?

Now I look at it, although the system can produce 24v, this section of the circuit could be 12 volt, for sure.

 

Now I look at it, although the system can produce 24v, this section of the circuit could be 12 volt, for sure.

That answerers neither of my questions.

 

I redrew the circuit with just a 3POS-CO heavy duty toggle switch.
Switch position up connects batteries in parallel.
Switch position down connects batteries in serial.
Switch position middle (center-off) opens the load.

But I suggest using a circuit that prevents changing the battery connections unless the load is disconnected first.

 

That wiring diagram is a bit confusing. The rectangle at the bottom that looks like the symbol of a switch is tagged input output.
The drawing in post #11 is much easier to understand.
AND the change over could be achieved with only adding one more relay, cheaper than with that expensive switch.

 

PK. It seems my inane inquiry is raising confusion and criticism. Too much for silly beginners like me.
Thank you all for your contributions. I'll end the discussion until I get better educated. thank you

 

The question was reasonable for a beginner. What happened is that folks got excited and wandered away from the original topic. That happens some times, it is not at all personal. Just some folks with excess time on their hands. I am recovering from some major surgery this past Tuesday, so my activities are a bit limited. Presently I have time on my hands for a few more days.

 

@SouthEastRay BTW the picture shown in your OP identifies it correctly as a 'Contactor' rather than relay.

 

@SouthEastRay BTW the picture shown in your OP identifies it correctly as a 'Contactor' rather than relay.

Of course the basic function of both is the same.