Help with circuit design/layout

liamo1991

HI all,
I am trying to work out how to do this type of circuit or if its even possible, I dont know alot about circuits and circuit device ( I know a bit but basics). I will try to explain as as well as possible what I am looking to do with it with photo attached.;
I am wiring up a machine drive hoping to use the like of a tractor battery to drive the motor, wiring that is no bother. What i need help with is what I call 'Socket Box' in the picture, I am hoping to be able the run safety switche(s) (red button) but I don't want to run the main power wire back to each of the switches as they could be up to 30ft away from this circuit.
Is there a way of just allowing a smaller guage wire to run from the safety switch to the 'socket box' so once the switch is pushed it cuts off power (breaks the circuit). Hoping to achieve this in a manual since but if necessary use battery power (via light wire to other battery terminal) to trigger the switch

I know I have ranted on a bit but hope it discribes it good enough and hopefully help me with this
Thanks.

Figerty

liamo1991 wrote: »

HI all,
I am trying to work out how to do this type of circuit or if its even possible, I dont know alot about circuits and circuit device ( I know a bit but basics). I will try to explain as as well as possible what I am looking to do with it with photo attached.;
I am wiring up a machine drive hoping to use the like of a tractor battery to drive the motor, wiring that is no bother. What i need help with is what I call 'Socket Box' in the picture, I am hoping to be able the run safety switche(s) (red button) but I don't want to run the main power wire back to each of the switches as they could be up to 30ft away from this circuit.
Is there a way of just allowing a smaller guage wire to run from the safety switch to the 'socket box' so once the switch is pushed it cuts off power (breaks the circuit). Hoping to achieve this in a manual since but if necessary use battery power (via light wire to other battery terminal) to trigger the switch

I know I have ranted on a bit but hope it discribes it good enough and hopefully help me with this
Thanks.

`
You need a relay, easiest option. I will draw up one for you. Would need to be checked by an electrian for earthing etc.

liamo1991

Figerty wrote: »

`
You need a relay, easiest option. I will draw up one for you. Would need to be checked by an electrian for earthing etc.

Thanks that would be great

Figerty

Hi liamo1991,

Shown is the basic logic of the circuit you required. 24v shown but swap for 12v.

For this circuit you will need a start switch, normally open.
A Emergancy stop switch, Normally closed with detent or latch switch.
Two relays, one to power the E stop.

The other to power the motor on.

Starting with line 3. The E-stop switch has to be wired with power on all the time for safety. This allows relay K2 to be powered up, thereby closing switch K2 on line 1. (i will get back to this later)

The logic behind this circuit is this. When you push or make the start switch, current flows through the now closed K2 swtich allowing current to flow to K1. This then closes the K1 on Line 2, keeping the relay K1 turned on.

When relay K1 is turned on, the K1 switch on Line 4 also closes allowing power to flow to the motor, causing it to start.

In this circuit, for some reason the power drops the circuit will not re-start unless the Start button is re-pressed.

Secondly, the E-stop kills power to relay, killing the latch and stopping the power to the relay.

The disadvantage of this circuit is that when run from a battery, K2 is drawing some current (depending on rating) however this is a safety feature, secondly.

You could us a normally open E-stop switch and a normally closed K2 switch (line 1), but should a wire break on the Line 3 circuit the E -stop won't work and you won't know it untill there is need for it.

One other thing, the E-stop is also your normally stop circuit, so there is no power through it when the motor is not in use.

Hope this helps!


Anyone else got any other solutions?

Figerty

One small error,, the switch on line 3 is shown as what is called a momentry swtich. this is a switch that springs back once you release it.

You need a detent swtich, this is one that when pressed stays latched or locked closed. This also mean the circuit can start unless it is released.

2011

Figerty, K2 is not required. Replace the NO contact in series with the K1 coil with the E Stop.
The correct control circuit is shown on the left hand side below (the drawing on the right does not apply in this case).

liamo1991

Thanks for them, will try get some time to look and study them properly over the weekend, came across this just wondering is this possible just replace the toggle switch with the emergency stop switch. I know its for reversive motors or is there a relay type simular to this that allows the power to be isolated

TOEJOE

Hi
The circuit shown is to be run by a battery , is this just to control the switch circuit for the motor?.

Confused

Figerty

True, as long as the E-stop is a latching switch for safety. When you turn of the E-stop (rather than just a stop switch) it needs to be reset before restarting.

It's an E-stop he needs. I usually use the second relay on more complex circuit to ensure that actuators retract on Electro-pneumatic circuits.

Nice software, What is it? I used Festo FluidSim.

2011 wrote: »

Figerty, K2 is not required. Replace the NO contact in series with the K1 coil with the E Stop.
The correct control circuit is shown on the left hand side below (the drawing on the right does not apply in this case).

Figerty

There are many many ways of solving this problem.

A toggle switch will do that for you like you have shown, but make sure there is a mid postion that is an off position. If you wire as shown there it appears the motor will always be running forwward or backwards.

An E-stop needs to kill the power to the motor. Make sure you get that bit right!

liamo1991 wrote: »

Thanks for them, will try get some time to look and study them properly over the weekend, came across this just wondering is this possible just replace the toggle switch with the emergency stop switch. I know its for reversive motors or is there a relay type simular to this that allows the power to be isolated

liamo1991

This is the basic principle i was looking for jjust wondering the type of solinoid that is? http://www.performance4trucks.com/Electrical/Remote-Master-Disconnect-with-Emergency-Push-Button-by-Painless.aspx?t_c=72&t_s=12&t_pt=6326&t_pl=3586&t_pn=PWP30205&utm_source=google&utm_medium=froogle&utm_campaign=product&emlprox=out

2011

Figerty wrote: »

Nice software, What is it? I used Festo FluidSim.

No idea to be honest! I just Googled DOL starter.

In work we normally use CAD, but only the CAD department are permitted to CAD up drawings for formal issue. As CAD resources are scarce I normally end up doing electrical schematics in Visio. I find it great. I am told that Visio drawings can be imported into CAD, but have not seen it done.