Start second device when first device starts working

[rdsn]

I'd would like to know if/how to turn on a second device (220V fan) when another device starts working automatically (air compressor).

The idea is to have both always plugged to the electricity, but the fan working only when the air compressor kicks in. Could someone guide me how to do it without touching the air compressor electrics (it's new, still on warranty)?

Many thanks

 

[Lucien Nunes]

Detect the current in the compressor supply cable, which can be done anywhere so no need to tap into the compressor wiring itself. A current-transformer and simple meter with a threshold detector that can energise a relay for the fan.

In fact you can buy this ready made, in the form of master / slave controlled socket strips. Don't have time now to look up the specs but you would have to check that they are highly rated enough for the compressor load.

 

[PEG]

Hi,there are a few details required,before advice can be offered.
What voltage and phase type,load size,type of connection (plug,hardwired,etc),any lag or after run required,distance between loads,reason for method...
The more information we have,the sooner we can start arguing amongst ourselves
...morning,Lucien

 

[static zap]

If a compressor is envolved , can a
thermal sensor be applied to a hot/cold part ,
will get some extra cooling when it shuts off .
(If fan is more powerfull than needed it will self regulate )

 

[rdsn]

Thanks for the replies. The compressor is a small one, 50L single phase with 2 motors, 0.75 hp each. That's 1120W total I think, so about 5A. Voltage is 230V.

It does state a "Start instantaneous power" of 2520W so... should it be rated for 11A?

The fan has a 230VAC | 50/60Hz | 15/12W sticker. 65mA?

The reason for this is I'm making an insulation box to avoid having neighbors complaining about the air compressor noise. The temp sensor would be a nice feature, but I would like to keep it simple (doable/understandable for me) and also reliable/budget.

 

[Bubba sparks]

Sounds to me like you need an enclosure thermostat to control the fan in your enclosure. I can't see how your going to achieve what your after any more efficiently. Obviously we don't know what type of fan your planning so down to you to confirm suitability. Try something like this
Understanding How Enclosure Thermostats Work in Electrical Enclosures - https://axaironline.co.uk/blog/how-does-a-thermostat-work.html

 

[Wilko]

Just a thought, but for the cost of setting up the triggering for the fan you could pay for the 15W for a long time. Perhaps if the fan just went on when you turned the compressor on it might not be that bad ?
On the motors, if you've got 1.5hp I'd expect that sort of number. I assume the compressor plugs in?

 

[Lucien Nunes]

Yes if the compressor has a fairly short duty cycle, i.e. spends more time off than on, much of the heat produced during each run will still be stored in the metal parts when it stops, so you would want the fan to run on, maybe continuously. This would allow smaller ventilation passages and hence less noise escaping.

Look at items like this but ensure the master socket can take the load: https://www.theecostore.co.uk/eco-store/buy-multi-socket/

 

[rdsn]

The compressor plugs in with a normal EU male socket.
My fan is this one: M91.0301 - https://www.maiatronica.com/index.php/reparacao/ventiladores/product/view/252/23125

The enclosure thermostat seems to be a much better approach than having both devices start and stop working at the same time.

I was looking for the thermostats and in the meantime found these: Digital LED Temperature Controller 220V 10A Thermostat Control Switch Probe M | eBay - http://www.ebay.com/itm/Digital-LED-Temperature-Controller-220V-10A-Thermostat-Control-Switch-Probe-M-/152333459579?hash=item2377c8207b

They have a probe which is a nice thing for my application. The price and the display is also nice. They lack a battery or an analog temp setting, so I guess I would have this always connected and my box external power switch would only cut the power to the compressor. What do you think of this?

 

[Bubba sparks]

In theory, it looks good but I would say cheap Chinese eBay electronics? I wouldn't be fitting that myself. See if you can find a sensible equivalent from a reputable supplier, then you should be good. Might cost you a bit more now but be cheaper in the long run.

 

[Bubba sparks]

Also meant to mention, that fan. Not that I'm an expert in what your trying to do but is it up to the task? Looks a tad small for cooling a compressor

 

[PEG]

Also meant to mention, that fan. Not that I'm an expert in what your trying to do but is it up to the task? Looks a tad small for cooling a compressor

That would be my guess,too. If it is for cooling,in an insulated box,it may help,but is more suited for a small welder or IT device.
If the reduction in noise is hoped to be achieved by way of negative pressure,it will certainly not be up to the job.

To the OP,what is the use to which this compressor is to be put?

There may be other options,which may be beneficial to both yourself and any neighbours.

For instance,i have a customer who had a large,noisy compressor,for his orbital sanders,used in the furniture job. He ditched it,after trialling some Festool Rotex machines (240V),which he said were five times better.

A host of what were primarily pneumatic tools,such as sanders,nailers and spray guns,are now replaced by electric,battery and airless technology.

...If you have a balloon factory or flag test tunnel...ignore me

 

[rdsn]

The compressor will be mainly used to blow cleaned up parts and do some painting. Occasionally inflate tyres or for compression test tools.

This compressor does not get very hot, so I would like to start first with a small fan and control the temperature with a module like the one above (not chinese), keeping an eye on the temperature inside the box. Then if needed I could add another fan. The idea is to avoid having big holes in the box, but I don't want it to overheat either. I'm open to other suggestions.