Contactor for lighting - 8NO contacts

[Designmen90]

Hello everyone,
here I have a situation where I need contactor with 8NO (normaly open) contacts. I found some Schrack device, mini contactor LA100773.
LINK: Mini Contactor 4NO, 3A, 230VAC - Online Shop - Schrack Technik International - https://www.schrack.com/shop/distribution-board-equipment-mcb-rccb-spd-mccb-terminals-fuse-material/contactors-thermal-overload-relays-and-motor-protection-switches/electromechanical-contactors-series-la/micro-auxiliary-contactors-size-1/mini-contactor-4no-3a-230vac-la100773.html
The contactor is needed for schematic from attachment, so lighting circuits will be protected with B10A circuit breakers. On contactor specification writes 3A, but if we look at datasheet (attached) there we will see Ith screw 10A ,so I think that this contactor will be suitable for this specific lighting!?

Any suggestion are welcome. Please help!
Sure, with auxiliary 4NO contacts, to get 8NO.

 

[Spoon]

What about this?

3TH4280-0AP0 | Siemens SIRIUS 3TH4 Contactor Relay, 230 V ac Coil, 8-Pole, 10 A, 8NO | RS

uk.rs-online.com

 

[Pete999]

Hello everyone,
here I have a situation where I need contactor with 8NO (normaly open) contacts. I found some Schrack device, mini contactor LA100773.
LINK: Mini Contactor 4NO, 3A, 230VAC - Online Shop - Schrack Technik International - https://www.schrack.com/shop/distribution-board-equipment-mcb-rccb-spd-mccb-terminals-fuse-material/contactors-thermal-overload-relays-and-motor-protection-switches/electromechanical-contactors-series-la/micro-auxiliary-contactors-size-1/mini-contactor-4no-3a-230vac-la100773.html
The contactor is needed for schematic from attachment, so lighting circuits will be protected with B10A circuit breakers. On contactor specification writes 3A, but if we look at datasheet (attached) there we will see Ith screw 10A ,so I think that this contactor will be suitable for this specific lighting!?View attachment 64490View attachment 64491
Any suggestion are welcome. Please help!
Sure, with auxiliary 4NO contacts, to get 8NO.

Why not get a bigger contactor to control a Lighting CU, 2 n/o contacts would be all that you need.\, controlling the feed to the CU Simples.

 

[Lucien Nunes]

The MCBs feeding the circuits seem to be numbered up to 70, so this might be part of a more extensive or complex system where it might not be practical to add another distribution board. Indeed the existing MCBs might not be in a conventional DB, e.g. we sometimes need to control blocks of outputs from entertainment lighting racks that are fed from multiple independent sources.

The OP does not mention the switching duty required of the contactor he linked nor the actual type and current load of the lighting. The contacts do have an Ith rating of 10A at 40°C but only 6A at 60° which is not unusual within equipment. Therefore if the load is anywhere near 10A I think I would want a larger contactor. The only other rating given is for AC15 which is not directly applicable to lighting, but might not be far off the mark for switching high-inrush LED drivers.

TL;DR: Without more info, that contactor rating looks marginally low for the purpose.

 

[Darkwood]

Why not get a bigger contactor to control a Lighting CU, 2 n/o contacts would be all that you need.\, controlling the feed to the CU Simples.

What about the inrush of multiple inductive loads taking out the protective device for the lighting CU, not sure how many light and circuits he has here but one has to be careful of too much inrush and why we have sequenced switching in big buildings.

 

[Spoon]

What about the inrush of multiple inductive loads taking out the protective device for the lighting CU, not sure how many light and circuits he has here but one has to be careful of too much inrush and why we have sequenced switching in big buildings.

That's what I thought, but as the drawing shows the contacts he has circled as -K1 then I presume that they are coming on all at the same time. There is also a -K2 contactor, maybe that's staggered from -K1...

 

[Designmen90]

I just need suitable 8 NO contactor for 10A loads.

 

[Spoon]

I just need suitable 8 NO contactor for 10A loads.

I proposed one in post #2. That was just a quick search on RS Components.
Lets see if the OP thinks it's suitable. If not then there are more out there.

 

[Darkwood]

As asked before, we need more info' as to the design:-


-No' lights per contactor pole
-Size and type of load
-no' of contactors and spacing between them
etc

I have designed and fitted plenty of these in the past usually rectifying other peoples mistakes, getting a multipole contactor could cause you problems especially with inductive load than it gives in convenience, I use lighting contactors 2pole specifically designed for lighting inductive loading and fit these in a dinrail panel, I lose half the space because I have to fit spacing units between the contactors to ensure they can disperse the heat properly.
With all respect we are trying to advice you but we are lacking info' info that could change the advice we offer, using a 4pole contactor creates it own problems that may see its life expectancy reduced or worse unless you over rate it by a good margin but this all depends on the load and the type and no' of units.
A quick yes/no answer is not always possible without more details and I think this is one of those occassions.