RCD info?

[supersparky]

T1, Is this what you need or am I dreaming ?

https://omronfs.omron.com/en_US/ecb/pro ... -E1-05.pdf

[jon_d]

Terry;

I'm not sure.

Solid state switches (FETs) are like a variable resistor. Turned off is like infinite resistance. Turned on 'hard' is like low resistance. and then there is in between.

I can't see a flash over in the traditional sense, because the fet is all sealed. There would not be an arc per se.
However, there is possibly of voltage breakdown. The solid state relay spec would need to be higher than Voc and plus some more.

Just be careful, you're playing around with deadly voltages. DC makes the muscles grip and hold. A few milliamps at those voltages will kill.

Something like this spec may work;
https://fastron.com.au/collections/dc-s ... ucts/d5d10

500V DC at 10 amps


Dave, have a look at the specs. The last page shows a maximum switching capacity at 175V DC with a maximum switched voltage of only 250V

[Busman]

David,
I think you are looking for a jobber unit that will allow you to run some single phase inverters (generic ?)
Unfortunately the Rich Electric (Invertek) have their own proprietary box that does this but then the software is extensive with over 400 selectable options. So I doubt this would be of interest for you ?
Cheers
William

[T1 Terry]

Terry;

I'm not sure.

Solid state switches (FETs) are like a variable resistor. Turned off is like infinite resistance. Turned on 'hard' is like low resistance. and then there is in between.

I can't see a flash over in the traditional sense, because the fet is all sealed. There would not be an arc per se.
However, there is possibly of voltage breakdown. The solid state relay spec would need to be higher than Voc and plus some more.

Just be careful, you're playing around with deadly voltages. DC makes the muscles grip and hold. A few milliamps at those voltages will kill.

Something like this spec may work;
https://fastron.com.au/collections/dc-s ... ucts/d5d10

500V DC at 10 amps


Dave, have a look at the specs. The last page shows a maximum switching capacity at 175V DC with a maximum switched voltage of only 250V

Thanks Jon, the switched current is quoted as 9.2 amps, that is within the 10 amp window but only just, would I be better looking for something rated at 15 amps or even 20 amps so it wasn't working close to its upper limit?
I was looking at these https://au.rs-online.com/web/p/solid-st ... s/4728976/ but it doesn't say if they are AC or DC on the load side, as far as I understand it requires different components to switch AC compared to DC.
Getting rusty here so I'm not sure about the next bit, is it Thyristor for switching AC and a Mosfet for DC voltage, there was another one that handled higher voltage better than a mosfet but I can't remember the letters DGBT or something like that?

T1 Terry

[supersparky]

T1, I wouldn't recommend that one. I think it might let the smoke out. Like you, I think thyristor is AC and mofset is DC. However, I have been wrong before.
While I was scrolling around the RS website that you linked to, the live chat icon popped up in the bottom RH corner. Why don't you have a one on one with their technical guys. They will refer you to their person that knows what he is trying to sell, and will have a much better insight to their product range.

[jon_d]

Higher spec is always better.

You may find that the on resistance is lower for the higher current rated devices. Thus, it gives a lower voltage drop and heat.

One of the advantages of the high voltage system is lower current; therefore, there is less voltage drop across these switches.
(another reason why I use a 115V string set up on the bus.)




Re: using AC units. No, I don't think you can. The SSR will only turn off when the ON signal is removed AND when the AC load crosses though zero. Being DC, it will never cross through zero and therefore, not turn off.

Also, assuming it could be turned off, you would need to derate the device because the each side of AC switch is only carrying current 50% of the time and is rated at RMS. DC will use one side 100% of the time.

https://www.electronics-tutorials.ws/po ... relay.html


Here are two;
http://www.crydom.com/en/products/panel ... sc-series/

http://www.crydom.com/en/products/panel ... 000-25-12/
http://www.crydom.com/en/products/panel ... 000-25-24/

[T1 Terry]

I thought the first one was painful @ $257.51ea but the 24v model $477.33ea and I'd need 4 of them unless the diode idea would work .... would need to sell a lot of sparks back to the grid to cover than sort of outlay. Let's see, approx. $2000 (if you include delivery) at $0.10 per kWh (the rate for sale back to the grid) = not likely to ever see a payback


T1 Terry

[Kappy]

There's a lot of techo dialog here, leaves me with a headache.

Question.
Can these RCD's ever become faulty?

I have one on my rig that seems to have a mind of its own, appears to trip when no apparent load. Will go a month using kettle and other high wattage appliances and then trip and not be able to be reset for several hours then rest and then appear OK for days then trip.

No pattern that I can see.

When OK I can run Kettle and another appliance (1400 watt) off the circuit no problems.

Thanks in advance,please simple dialogue.

[jon_d]

Can these RCD's ever become faulty?

Yes.


The cheapest way of testing is to replace it with a new one. $20-40 these days. Something like this.
https://www.sparkydirect.com.au/p/RCBM2 ... b-rcd.html

Make sure you get a double pole unit.
Double pole switches both wires (active/neutral, blue/ brown).
Remember; All AC work must be done by a licensed person.


If the new one trips, then you have a problem with the wiring.

OK Kappy?

jd

[Kappy]

Its this one.

20200915_122928.jpg

Seems different to link.