Thread: Any Electricians Around Here?

Hi Mini,
Yes you can get 32V Relays AC or DC like the Finder 60.12 Series, they can switch a motor up to .37kW. There are timers that can give you a Delay Timing e.g. Carlo Gavazzi DBA-52 but they operate on either 24VDC or 24-240VAC.

Regards,
Keith.

Thanks Keith, I think I will go with the 32V overhead switch idea, the only issue with that is if a machine is moved. I might just put a few in central to the machines so the cyclone can be switched on from close to each machine. That way I don't need to put a delay timer in. I don't think I can start it from a voltage drop as a machine switches on as half the machines are three phase thus on different circuits. Also the compressor is on the three phase and every time it starts the cyclone would fire up.

Hi Mini,
If it is of any help if you would like to do a sketch of your circuit showing the Switch and Motor locations, sizes and types I could work out a circuit for you. I have quite a number of Relays, Contactors etc that you could have if suitable to your circuit.

Regards,
Keith.

For switching the contactor you could also consider using an RF or infra red remote control (the type used for garage door openers). You can buy these cheap online and I think even Bunnings have these now (though I have found better/smaller ones online).
You can then have the controller(s) in your pocket, nearby, or attached to your machines.
Might be some safety implications to think through here though i.e. a bit easier to accidently turn on your dust extractor with a remote control in your pocket compared to an overhead mechanical switch.

I have problems with finding things and a remote control has a high risk of annoying me to say the least. Also I can wire the 32V side of it myself with no issues as DC is simply two wires and they can go down the ducting. The switches can be mounted on the ducting and the whole thing becomes fairly simple, the more I think about it the more I like it.

Isn't life wonderful sometimes. I went to Keith's place tonight and he gave me all the gear and complete advice on how to hook up and run the system using a switched low voltage control circuit. Thanks Keith I owe you a beer some time.

Mini.
There may be a simpler solution to your problem but I would require a drawing of what you propose.

Also, 'contactors' have different ratings. The contactor you need must be rated at the 'AC3' kilowatts of the equipment that they will supply. If you select a contactor based upon AC1 (for example), you may find that you will need to replace the contactor within 10 years (depending upon how many operations it performs). In case you think that '10 years is nothing', when a contactor fails (a failure of a contact), it can cause problems/damage to the equipment to which it is connected.

If you plan to use a contactor to control a motor, you will also be well advised to use an appropriate 'thermal overload'...this especially applies to 3 phase motors.

If you want any other 'electrical' advice, it can be found in the 'Renovate Forum', which is a part of this forum. The Renovate Forum has people who are familiar with & qualified to give advice about many electrical problems/questions.

The Renovate Forum can be located by the link, which you will see on the left hand side of the main Woodwork Forums page, under 'Extras'.

Originally Posted by elkangorito

Mini.
There may be a simpler solution to your problem but I would require a drawing of what you propose.

The problem is anyone who uses a dust extractor and multiple machines faces, that of starting the DE without constantly having to go to a central switch and then return to the machine, do the work then again go to the central switch and turn it off. Some choose to use a remote control(s) but it would drive me more batty than what I am already. Others choose to operate via blast gate switches with the wiring in the ducting, my blast gates will be well above my head so I don't want to use them as switches though I could still do that. Others have used pneumatics to drive cylinders, but having been involved in pneumatic control many years ago I don't like the complication.

For all the above reasons I have chosen to use four overhead switches to control the motor, to avoid having 240V running through the ducting I intend to use low voltage control as I already had a 32V power supply. It also means the switches can be close at hand but not in the way and all up it seems to be a reasonable way to do things. Having said all that is someone can simplify it I welcome their input. The only way I can see to simplify it is less switches and use high voltage all the way through the control circuit in which case I don't need a contactor unless the switches can't handle the start load which would be possible as they are only light switches in their original intended use.

As I said to start with, a perennial problem for all those who use a DE and multiple machines and everyone has a different take on the answer. Any input by anyone is more than welcome.

Mini, I have followed this thread and figure that you are probably on the right track using multiple low voltage (applied, not rated) switches in parallel to control a contactor for the dusty, given the constraints that you have identified - dislike of remote control due to misplacing them, and poor access to blast gates.

The one thing you need to be carefull of is the use of magnetic switches or contactors as standard switchgear of the dusty. If this is the case with the unit you have, then the wiring will need to be modified, probably at the expense of warranty on the dusty.

If the add on contactor is simply placed between the power outlet and the standard switch gear, the magnetic switch will 'drop out' each time the contactor releases, and the dusty will not restart when the add on contactor is reactivated.

If the add on contactor simply replaces the original switch gear, any overcurrent or phase loss protection provided by the original switchgear would be lost, and chances of successfull warranty claims for the electrics would be very slim.

It should be possible to integrate the add on contactor/relay into the control system of the original switchgear so that the original gear still provides the switching and protection, and the add on merely duplicates the push buttons. If you think this is applicable to your situation, send me an email with a sketch of the wiring diagram of your switchgear and I will send back a suggested method of remoting the switchgear.

Mal

This is a brand new five year old Carbatec cyclone so the warranty is knackered anyway. Yes, I know I should have put it in a long time ago but I haven't owned it all that time, only three years. It does not have a magnetic switch so that should not be an issue and I presume you are speaking of the power on/off switch here, not an internal control within the motor. I could still put switches on the blast gates but I reckon it is a pointless exercise designed to impress people, the same with pneumatic or solenoid controls, impressive but in the end pointless. I reckon a cord hanging down over the middle of the machine is simple and to the point and exactly where it should be and I can't lose it nor do I have to operate a blast gate before and after each machine use and the last I had not thought of until now, each time the DE has to be turned off the blast gate has to be operated. No thanks. I will surface mount the switches on the duct run the wire straight in through a grommet. The more I think about it the more I am convinced it is a good way to operate a DE from multiple points.