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LED indication over long run.

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I am attempting to indicate a roller shutter has been left open with an LED indicator located at a drivers desk (point A)... the roller shutter is at point B with a lever that when bolted across a relay operates to N.O.

 

Distance from point A to point B is 200m.

 

What's my best way of doing it i.e. voltages and size of cables....

 

I was thinking of sending a +24VAC down one core from a panel that were having made, running through the relay to connect directly back to the LED indicator. and have 0v connected straight from panel to indicator....

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Shutter is on a internal section going into a segregated part of the building so no use in this instant. Door is not alarmed.

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1 minute ago, Nova-Security said:

Hes using a relay to switch it, so the power must be local to the LED so volt drop doesnt matter. 12vdc 1k resistor 

 

Volt drop will matter as I'll be running the power through the relay 200m away? Power will run from the "panel" through the relay 200m away then back to the LED which is located on the panel... so round trip of 400m...

 

I'm just wondering if there's a better solution.

 

23 minutes ago, sixwheeledbeast said:

Would need to be DC for LED unless you want it to flash at 50Hz?

What kind of LED, how much current? Then you can work out volt drop.

 

Current is 20mA.. LED is the type is fitted on industrial switch panels?? if that makes sense.

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48 minutes ago, Nova-Security said:

Hes using a relay to switch it, so the power must be local to the LED so volt drop doesnt matter. 12vdc 1k resistor 

 

It doesn't matter where the relay is there will still be current through the switch to trigger the relay.

38 minutes ago, ElecTech said:

 

Volt drop will matter as I'll be running the power through the relay 200m away? Power will run from the "panel" through the relay 200m away then back to the LED which is located on the panel... so round trip of 400m...

 

I'm just wondering if there's a better solution.

 

 

Current is 20mA.. LED is the type is fitted on industrial switch panels?? if that makes sense.

 

Yes, so they will have there CLR built in so need a 24Vdc or 12Vdc supply to your panel mount.

You need to calculate the resistance of the cable you are using and use V = I/R

I imagine 1mm 2C flex would be fine with such a small load on 24Vdc.

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1 hour ago, ElecTech said:

 

Volt drop will matter as I'll be running the power through the relay 200m away? Power will run from the "panel" through the relay 200m away then back to the LED which is located on the panel... so round trip of 400m...

 

I'm just wondering if there's a better solution.

 

 

Current is 20mA.. LED is the type is fitted on industrial switch panels?? if that makes sense.

 

Why run the poer to the relay at the contact and back?

 

Run the contact wires to the panel RB007 trasistorized relay then its only doing 200m 

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Eh? I think we have both read this differently.

I see this as A (the LED) and B (the relay output).

I assume there is no power at B, A would be easiest place to locate PSU as it can go in the cab.

One run of 200m 2C 1mm should do the job?

 

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200m is quite a long run, just an idea that I've done similar before is to use the fire alarm system to pass the signal.

 

 

It does depend a lot on the system, but many will let you have a supervisory signal that doesn't show on the panel etc but allows an interface at the roller shutter to be connected to a sensor of some kind, and then switch another interface at the other end to light up the LED. If its Apollo then you could just put the interface somewhere can be seen, then when it operates the output - the LED on the interface will come on so you can stick a dymo label on it accordingly

 

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