hi,
The d/s is not clear about the 100mSec operation.??
I would suggest you contact Panasonic Tech support.
https://www.justanswer.co.uk/sip/panasonic/?r=ppc|ga|5|1630259688|65808049601|&JPKW=panasonic technical support&JPDC=S&JPST=&JPAD=311918492341&JPMT=e&JPNW=g&JPAF=txt&JPRC=1&JPCD=20181104&JPOP=&JCLT=&cmpid=1630259688&agid=65808049601&fiid=&tgtid=kwd-1631886788&ntw=g&dvc=c&gclid=EAIaIQobChMIwqTBxN-d7gIVF-ztCh3BTgA4EAAYASAAEgKz2PD_BwE
It would also help if you could post a simple diagram of the project.
E

I have emailed them but no reply yet. Let it be 100ms or 1 sec to activate the coil. My concern is, do i know the last position of the switch lever if i use built in manual switch? or is it similar to momentary switch which comes back to normal position or it stays in the same position ( either set or reset)?

 

According to the spec, Max. set/reset time is a 20mS pulse.
I interpret that to mean "apply the rated coil voltage for no longer than 20mS, then remove the voltage".

There is a later statement made under "Precautions for Coil Input":

"Continuous, long-term current to the coil will facilitate deterioration of coil insulation
and characteristics due to heating of the coil itself."

Here is a clip from the Product Selection Guide:

 

I haven't added much input because lots of what you're already getting is good information. However, I've decided to sketch out two different ways of using a DPDT relay and two pushbutton switches. In example 1 the RESET switch is a normally closed pushbutton and the SET button is a normally open push button. You press the SET button and it energizes the relay. One of the two sets of contacts connects power to the relay and it keeps itself energized. When you push the RESET button you de-energize the relay and the contacts open. In example 2 there are two normally open push buttons. Each is wired to opposite sides of the coil. It also uses a resistor to prevent the possibility of dead shorting the power source to ground. When you press the SET button the relay latches on (same as example 1). Once energized it remains on. When you press the RESET button you effectively provide the same potential voltage to both sides of the coil and no current flows, thus, the relay drops out. The resistor is sized small enough so that there is enough current through the coil to make it latch but not so small that when you press the RESET button you draw massive amounts of current. The resistor wattage needs to be big enough to handle the worst case current flow. If you're using 12 volts and the coil has a minimum current requirement of 200mA then the resistor should be 60Ω maximum. This will provide sufficient current for the relay to latch and remain latched. When you press the reset button the wattage (wasted heat) will be 2.4 watts. However, that will be momentarily the case because you're not going to hold the RESET button. You can probably get away with a 2 watt resistor.

Here are two examples as described above:

 

Looking at my drawing, I've had an epiphany - there's an even better way to RESET the relay. The illustration below shows that the RESET button can only be activated when the relay is self latched. Thus, when you push the RESET button the relay drops out and the current stops immediately, thus NOT overheating the resistor.

 

The illustration shows that the RESET button can only be activated when the relay is self latched. Thus, when you push the RESET button the relay drops out and the current stops immediately, thus NOT overheating the resistor.

Where does the coil for reset get its ground?

 

hi,
The clip from post #2, clearly states a 100mSec for R and S to ensure operation.

The TS has a method for operating the relay, but he is now asking for some form of State indicator.

As he is switching a 400V contact voltage, additional circuitry is required to show the current state.
E

 

U mean across NC and COM contacts? The line is working at 40A rms so I dont think it works.

A neon indicator from the relay output to AC neutral will give you an indication of the state of the relay.

 

Where does the coil for reset get its ground?

The reset shorts across the coil. In effect, assuming there's 12V supplied, with the coil energized it is holding the coil latched because one side of the coil is direct to 12V. The reset button puts that same 12V on the other leg of the coil. 12V to 12V means zero current and the relay will drop out. As soon as the relay drops out power is lost and the ground resistor is no longer conducting current. Thus, it doesn't heat up and burn. I'd still go with a 2W resistor. Maybe 50Ω. (assuming 12V)

 

hi C,
I suggested a neon, this is the TS's reply.
The relay will be switching 40A and 400V rms. But I am not going to do live switching because the relay is not rated for live switching.
E

 

hi C,
I suggested a neon, this is the TS's reply.
The relay will be switching 40A and 400V rms. But I am not going to do live switching because the relay is not rated for live switching.
E

Okay, I missed that in a different post.

 

In the post #24 circuit, you could add an LED with series resistor, from the relay 'C' to 'reset' button wire and ground to indicate the relay status.

 

I've read the thread twice now and don't see anything indicating what voltage the coil of the relay is. At present, it can be anything from low voltage to high. AC or DC. A little more clarification can set us off in the right direction.

If you HAVE this relay then you would use one PB for the SET and the other PB for RESET. An additional set of contacts would be needed to indicate position. I think the relay you show has only a single set of contacts for closing a switch. It's not SPDT or DPDT, it's SPST. In that case none of my diagrams will serve. In order to use your relay you need two momentary switches, whether Momentary PB or Momentary Toggle. As for indicating the state of the relay - you're going to need additional wiring, be it circuitry or another relay to mirror the control relay. We can help.

 

In the post #24 circuit, you could add an LED with series resistor, from the relay 'C' to 'reset' button wire and ground to indicate the relay status.

True. [edit] But there's potentially the max current for the LED and the min current for the coil. Plus, [end edit] after I've re-read the entire post I think the TS already has a relay in hand. Since THAT relay is a latching relay, indicating the position is going to require additional circuitry - or another relay.

@crutschow recommends a neon lamp across the contacts. That can indicate when the relay is "contacts open". That can provide a sufficient method for indication of an open circuit condition of the relay.

 

Here's what @AlbertHall is suggesting; and it's not a bad idea at all.

 

crutschow recommends a neon lamp across the contacts. That can indicate when the relay is "contacts open". That can provide a sufficient method for indication of an open circuit condition of the relay.

In considering a statement that the relay is not going to be used for live switching, IF power is off then the relay position will not be known because there will be no power for the neon lamp to indicate whether the contacts are open or closed.

 

hi C.
I am now wondering whether he is thinking that the suggested neon will be across the relay coil.???
and not on the output contact of the relay.
E

BTW: in translation is 'live' == 'Line'.???


Update:
A PS from his 1st post.
PS: Supply for the coil is coming from DC supply

 

Here's what @AlbertHall is suggesting; and it's not a bad idea at all.
View attachment 227846

The TS will be using a DUAL COIL latching relay as stated in post #15.

 

The TS will be using a DUAL COIL latching relay as stated in post #15.

Yes, thank you. I am aware of that. Others were suggesting different arrangements, but it seems that the TS already has this relay in hand. In keeping with that - here's a drawing of what Crutschow is suggesting with the NEON lamp. IF the relay is closed the NEON will be extinguished. IF the contacts are OPEN - AND - 400VAC is present (or DC, not sure) the NEON will be lit. BUT IF the 400V is NOT present, the position of the relay will be unknown. In the drawing is a toggle (not center off). The TS can use a center off toggle or two push-buttons, depending on the coil voltage requirements. However, with a spring loaded center off toggle (or PB's) there is no indication of position of the relay. That's why alternative suggestions have been posted.

 

IF the contacts are OPEN - AND - 400VAC is present (or DC, not sure) the NEON will be lit. BUT IF the 400V is NOT present, the position of the relay will be unknown.

Another Latent thought comes to mind - the 400VAC is on but there is no connected load the neon will not be lit. If the relay is closed and there is no load, say - an open wire - there's a potential of someone contacting high voltage. Even if the relay is open, there can be sufficient current through the NEON to present a danger to an unaware operator or maintenance person. I don't mean to be the guy who finds problems with the solution, but in this case, safety with that high a voltage and 40 amps potential present - safety is something that should not be ignored. A re-design may be warranted.

 

Post #38 circuit using a 'centre off' switch will give the momentary coil activation which is desirable. Using a standard switch would need a capacitor with parallel resistor in series with each coil to give a momentary actuation of the relay.

Another Latent thought comes to mind - the 400VAC is on but there is no connected load the neon will not be lit. If the relay is closed and there is no load, say - an open wire - there's a potential of someone contacting high voltage. Even if the relay is open, there can be sufficient current through the NEON to present a danger to an unaware operator or maintenance person. I don't mean to be the guy who finds problems with the solution, but in this case, safety with that high a voltage and 40 amps potential present - safety is something that should not be ignored. A re-design may be warranted.

The neon could be connected across the load instead of across the relay contact to avoid those problems.