three phase contactor

[naughtybear]

Hi Guys, please can someone help with a little problem I have........ please see photos! I would like to add a push switch to bring a motor in to turn over an engine (on a dyno) and I would like to use the contactor pictured but cannot for the life in me make it work , the single breaker appears to be supplying the control voltage and when I push in the contactor manually I get power up to where I will be connecting the motor cable. can anyone shed any light on this please?
racing regards Ash

 

[Lucien Nunes]

It would help if you could post a schematic of what you are trying to achieve. Presumably you've checked the coil & O/L? Note that one is set to auto reset and the other to hand. What control voltage? What type of switch? Are you an electrician? Sorry, so many questions, but difficult to know what to advise without more info.

 

[Deservices]

To bring in the contractor you need power going to a1 and a2 on the contractor. A2 generally neutral/negative depending on ac/dc voltage. A1 gets power from your start switch and via a stop button and the overload on the bottom of the picture, and a normally open contact on the contactor, all in series. So when you press start the circuit is made and the normally open takes over keeping it on until stop is pressed.

 

[telectrix]

check that you have the correct voltage on the coil 240V or 415V.

 

[naughtybear]

the button I have for making the circuit is one that you press to make and let go to break - the way I want it to work is just like turning the ignition key until the engine fires and then let it go again its ac 415 volt - the board I am using is prewired (unsure of its previous use) the breaker that appears to be supplying control voltage to a1/ is 6amp single phase (so presume I am right in thinking its 240 volt) a2 is connected down to terminal 95

 

[naughtybear]

rough image of what i want to do

sorry its a bit basic

 

[Lucien Nunes]

We can't see in the pics what else is connected in the control circuit but surely you can just follow it around, dead, with a continuity test, to spot the airgap. Is the overload tripped and in the hand reset position?

Things to consider:
If the engine can drive the motor once started, what about reverse power? (an induction motor will generate while it is connected to the supply)
Does the overload relay match the motor?
What emergency control provisions are required?
Does the installation need to comply with PUWER or the machinery directive and how will you certify it if it does?

 

[Knobhead]

A lost cause I'm afraid!

You don’t know what you are doing, that is patently obvious. I’m not wasting my time.

 

[naughtybear]

A lost cause I'm afraid!

You don’t know what you are doing, that is patently obvious. I’m not wasting my time.

its patently obvious you just have wasted your time by replying and isn't a forum for when you are stuck and are big enough to ask for help?

the motor is for the dyno to test race car engines and yes before you ask I already have a deadbeat for a sponsor so you don't need to apply

 

[Marvo]

Tony might sound patronising but your question is impossible to answer without a lot more info. There's also a tone to your posts that makes it sound immediately like you haven't considered the function of the control circuit and it's bearing on the safety of the system. You're not only dealing with a contactor that switches a motor on and off, you're dealing with a complete system that is providing motor control/switching, isolation, electrical overload, user safety interlocked and all this is mechanically connected to an engine on a dyno.

If you get this wrong and somebody gets hurt then you'll be in court. I'd also strongly recommend that you involve a professional designer at least to give you a specification and a control circuit. If you're competent then just wire it to spec from there.

 

[Knobhead]

its patently obvious you just have wasted your time by replying and isn't a forum for when you are stuck and are big enough to ask for help?

the motor is for the dyno to test race car engines and yes before you ask I already have a deadbeat for a sponsor so you don't need to apply

Why didn't you give that information?

Now retired I don't need help, I have 40 years of experience to pass on to those I trust.

 

[plugsandsparks]

Hi, I would love to help as I am a bit of a car nut myself. What I don't understand is: This is an existing panel, whats it used for? Is there already a switch somewhere to bring in this contactor, if so where is it. If not then its possible the contactor you want is already pre-wired to work in a different way and as such this will need altering so that it works the way you want, hence the question about what the panel is for. It may be easier to just use a non latching motor starter, off the shelf from a wholesaler. THree phase in and motor wires out. Start and stop are contained in the box it comes in and you can mount the box along side your desk. Just a friendly word of caution.... 400V hurts a lot and the flames can travel so don't stand in front without eye protection and preferably something covering your face , just yesterday I had a 2ft flame shoot past my right leg laced with molten metal but i'm a pro

 

[Darkwood]

I think you are trying to energise a pony motor from a control panel that used to run something else...

Firstly we need the rating of the motor.
You need to check the contactor(s) are suitably sized to do this motor and overload to suit.

You have pre wired existing system and as we don't know its schematic we cannot comment on the existing set-up and how to adapt, what supply have you got voltage and phase(s)
What coil voltage is the contactor?
Can i confirm you don't require the contactor to retain on start button but act as a dead man control in that you release start button pony motor drops out.

Answer the above and we will supply simply wiring plan.

Can we assume the speed and power of the pony motor is correct for the job you intend it to do and like the control panel this isn't a build it yourself DIY project from anything you find?

 

[telectrix]

Hi, I would love to help as I am a bit of a car nut myself. What I don't understand is: This is an existing panel, whats it used for? Is there already a switch somewhere to bring in this contactor, if so where is it. If not then its possible the contactor you want is already pre-wired to work in a different way and as such this will need altering so that it works the way you want, hence the question about what the panel is for. It may be easier to just use a non latching motor starter, off the shelf from a wholesaler. THree phase in and motor wires out. Start and stop are contained in the box it comes in and you can mount the box along side your desk. Just a friendly word of caution.... 400V hurts a lot and the flames can travel so don't stand in front without eye protection and preferably something covering your face , just yesterday I had a 2ft flame shoot past my right leg laced with molten metal but i'm a pro :-)

how did that happen? you been upsetting tony? :44:

 

[plugsandsparks]

how did that happen? you been upsetting tony? :44:

Ha - hopefully not. Was called out to a machine that kept tripping, there were several faults and was ironing them out one by one. One of the trippings appeared to be when the motor transferred from star to delta, anyway I could not see what was happening so removed the contactor guards from all the contactors to see what was happening, needless to say delta did not want to know and made a nice light show. That was shortly after a 16amp mcb tripped due to shorting between two phases across a contactor that had an eaten away phase barrier, that only produced a small puff of smoke. The other flaming contactor was trying to close a hundred or so amps. Wasn't the best of days.