Deo joseph
Posts: 17
Joined: Fri Mar 31, 2017 6:21 am

Re: Relays

Fri Apr 07, 2017 5:07 am

Hi..
Please guide me..What will be the form factor (Physical area occupancy) if i am using 48
G7L-1A-BUBJ-CB-DC12 relays.
http://www.mouser.in/ProductDetail/...- ... kecf2Puw==

trackerj
Posts: 7
Joined: Thu May 26, 2016 5:01 am
Contact: Website

Re: Relays

Fri Apr 07, 2017 6:38 am

Do you really need 20A/per channel? Are you sure?
ESP8266 MPDMv4 AC MAINS Dimmer Home: http://www.esp8266-projects.com/2016/04/mpdmv4-mains-dimmerswitch.html
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PiGraham
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Location: Waterlooville

Re: Relays

Fri Apr 07, 2017 7:04 am

trackerj wrote:Do you really need 20A/per channel? Are you sure?
Maybe this is some big industrial / stage lighting. It sounds like it needs profession kit, not something cobbled together by someone who doesn't know what they are doing.

20 x 48 = 960A! At 240V that's 230kW (230kVA) of lighting!
Even assuming there is a significant margin on that contact rating it's still a vast amount of power for a hobbyist.
I shudder to think of the legal and insurance liabilities of installing such a monster.

A really bright domestic bulb is 100W or 2.4A.

Depending on local laws people could be prosecuted for unsafe electrical installations, even in their own homes.

I think the normal approach would be to use DMX modules for each light.

pcmanbob
Posts: 8342
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Location: Mansfield UK

Re: Relays

Fri Apr 07, 2017 8:16 am

PiGraham wrote:
trackerj wrote:Do you really need 20A/per channel? Are you sure?
Maybe this is some big industrial / stage lighting. It sounds like it needs profession kit, not something cobbled together by someone who doesn't know what they are doing.

20 x 48 = 960A! At 240V that's 230kW (230kVA) of lighting!
Even assuming there is a significant margin on that contact rating it's still a vast amount of power for a hobbyist.
I shudder to think of the legal and insurance liabilities of installing such a monster.

A really bright domestic bulb is 100W or 2.4A.

Depending on local laws people could be prosecuted for unsafe electrical installations, even in their own homes.

I think the normal approach would be to use DMX modules for each light.

As PiGraham has said this is a very large lighting load, not a domestic load that's for sure, even for an industrial situation that's one big lighting load, if it is industrial than its going to be spread across 3 phase 415 volts which way beyond any thing I think this forum can advise on, if you really are switching that lighting load then you should seek professional help, as that sort of load be it on 240vac or 3 phase 415 vac being switched requires some serious design and planning to make it safe, this is no hobby project it requires professional design to make it safe and reliable.
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trackerj
Posts: 7
Joined: Thu May 26, 2016 5:01 am
Contact: Website

Re: Relays

Fri Apr 07, 2017 9:12 am

PiGraham wrote:
trackerj wrote:Do you really need 20A/per channel? Are you sure?
Maybe this is some big industrial / stage lighting. It sounds like it needs profession kit, not something cobbled together by someone who doesn't know what they are doing.

20 x 48 = 960A! At 240V that's 230kW (230kVA) of lighting!
Even assuming there is a significant margin on that contact rating it's still a vast amount of power for a hobbyist.
I shudder to think of the legal and insurance liabilities of installing such a monster.

A really bright domestic bulb is 100W or 2.4A.

Depending on local laws people could be prosecuted for unsafe electrical installations, even in their own homes.

I think the normal approach would be to use DMX modules for each light.
I was thinking at about the same. At that level driver board is separately from the relay block. Done something like that in distrubuiton boxes on DIN rails, with proper channels fuses, BUS Bars, 3 Phase load split & stuff.
20A x 48 MAINS Channels it not something to just play around. The good thing is that for a usual residential setup you don't have that amount of installed power. For a average inst power consumption of 960A you need a 1200A power line ( 3 Phase only). Only approvals, installation and monthly bill from the Electricity Company will be something quite scary :)
ESP8266 MPDMv4 AC MAINS Dimmer Home: http://www.esp8266-projects.com/2016/04/mpdmv4-mains-dimmerswitch.html
Available on Tindie: https://www.tindie.com/products/nEXT_EVO1/

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rpdom
Posts: 16347
Joined: Sun May 06, 2012 5:17 am
Location: Chelmsford, Essex, UK

Re: Relays

Fri Apr 07, 2017 9:24 pm

PiGraham wrote:A really bright domestic bulb is 100W or 2.4A.
Um, at 230V, 2.4A is 552W. A 100W bulb would require about 0.43A.

(I have some old, nearly as old as me! 275W 240V bulbs that still work, not that I use them any more)

Stephanisk
Posts: 5
Joined: Thu Apr 06, 2017 6:46 pm

Re: Relays

Fri Apr 07, 2017 10:26 pm

I don't know if i am a bit late but to your first question.

This is a matter of simple electronics. Switching 220v is not an issue, just use a small electronic relay with coil 3,3v that switches 12v, connect this one to an external power source of 12 voilt and now in second row find any normal switch in an appliance store that has coil 12v - AC 220v 20a and let the first relay switch the second . Your second relay is just switching the normal power in your house.

As easy as it can be. No worries about gpio max amps etc, just cascade it till u have normal electrical relays that are used in any household switchboard. No danger for overloading or breaking anything. That's how I solve issues like this. Little wiring and off u go. Hope this helps.

PiGraham
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Joined: Fri Jun 07, 2013 12:37 pm
Location: Waterlooville

Re: Relays

Sat Apr 08, 2017 7:00 am

rpdom wrote:
PiGraham wrote:A really bright domestic bulb is 100W or 2.4A.
Um, at 230V, 2.4A is 552W. A 100W bulb would require about 0.43A.

(I have some old, nearly as old as me! 275W 240V bulbs that still work, not that I use them any more)
Doh!
Inverted fraction and hasty post. You are correct, 100/240, under half an amp.

Deo joseph
Posts: 17
Joined: Fri Mar 31, 2017 6:21 am

Re: Relays

Sat Apr 15, 2017 5:21 am

hi..
which are the electromechanical relays suitable for controlling the fluorescent lamp with electronic ballast???

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