direction of motor

[dan18]

Hi all, how do I determine how to wire a motor up to get the right direction without using a phase sequence tester. The motor I am wiring up as got to go clockwise.

Cheers dan

 

[ProDave]

Will the machine be seriously damaged if it goes the wrong way?

If not just try it and see. If it goes the wrong way, swap two phases over.

Remove a belt or coupling if possible so you can try it without it driving the machine.

 

[Evans Electric]

What they said!!

 

[Apache]

Hi all, how do I determine how to wire a motor up to get the right direction without using a phase sequence tester. The motor I am wiring up as got to go clockwise. Cheers dan

Should you be doing this work if you haven't got some of the most basic test instrumentation? You can get a cheap Chinese phase rotation meter off ebay for as little as

 

[revjames]

50/50 chance of getting it right first time

 

[batty]

Butter it boith sides its a win win situation apart for dog hairs.

 

[Evans Electric]

Just as an addition to this, if its a more complex machine , I always get the client/operator/trained person to try it for direction , with the warning that it could go backwards , if they say it doesn't matter then fine , but I would say never, never start up a machine of your own bat, it could be insurance policies at 30 paces if you ****** them up.

TBH a simple grindstone/ linisher, drill sharpener is usually safe enough to try . Or a simple conveyor .

People have said to me that if you follow the RYB phases right through to the motor , it will run in the correct direction . This is not the case as the machine it is driving may need to run in either direction .

 

[Evans Electric]

Listen ., I wanna tell you a story.

I did half my apprenticeship with the maintenance sparks at GKN Witton . With the sparks , we had wired a socket to the control panels of these big presses ( from 450 ton to 1000 ton operating ) ( British Clearing) so they could plug in a foot operated switch on a flexible . These presses did cold extrusion pressings like the steel casing of a generator or starter motor for a car , from a cold solid billett, in one action , pressed and extruded into the finished product.

The press comes down and makes the pressing and as it returns an ejector below the dies follows the press , comes up through the die and ejects the job .

So, the sparks says to me , No3 press is not in production , go and plug the foot switch in and make sure it works . Anyway , luckily for me I asked the Pressshop forman if it was OK to try the switch, he said yes. Now these presses are the size of a 3 story house , and all the bosses happened to be right there , so I close the safety doors and shove my hoof on the switch , the press does an operation without a job in the dies , as it returns the aforementioned ejector starts to follow but its not set properly , it drops out of the dies and comes up under them , they erupt from the press bed ,wrenching out the huge holding bolts and buggering up the whole press bed.

To give the guy his due , the Presshop Forman agreed that I had asked and he had given me the go ahead, but it could have been nasty for me . Never forgot that.

The place was used for a film once and theres a still from it showing those presses , see if I can post it.

 

[Sidewinder]

I did my "time" on similar kit mate so I know the sorts of presses you are talking about.

 

[kerching]

Although that's never worked for me in real life, they always run the wrong way !A bit like dropping the buttered toast !

Here's an idea....if they always run in the wrong direction for you, then every time you connect one at the very last second swap 2 phases. Simples.................. :coat

 

[philbas]

Butter it boith sides its a win win situation apart for dog hairs.

Not if it lands on the cat that always lands on its feet

 

[Sidewinder]

Same here mate!

I have tried the reversing bit at the last second too, but, I probably get around a 60/40 split, mind that is pure luck!!!

 

[kerching]

Same here mate!I have tried the reversing bit at the last second too, but, I probably get around a 60/40 split, mind that is pure luck!!!

Your methodology is without fault!, you just need to perfect your timing........................ :coat

 

[pickleye]

You can do it with 2 light bulbs and a contactor - BUT i aint gonna tell you how

You tease!

 

[SPECIAL LOCATION]

Assuming a 3 Phase Induction MotorIf its a standard EU motor and hasn't had the terminal block wires tampered with (or been rewound) then for both star and delta connections

U1 - L1 Brown Phase (Old Money RED)

V2 - L2 Black Phase (Old Money YELLOW)

W1 - L3 Grey Phase (Old Money BLUE)

Earth - G/Y Green/Yellow (Most Important)

This Presumens L1-L2-L3 are clockwise on a phase rotation meter (i.e. your phases are correct)

If this is all true then looking at the motor shaft it should turn clockwise

HOWEVER as stated above its always best to disconnect the load and do a rotation check to prevent any possible damage or injury that could occur

:Salute :Applaud

Ah.... ha.....

I am surprised that Steptoe hasn't mentioned that if you are on a installation with mixed colours this is where you could get in a mix up if you start using the colour codes that some people like:-

where black = blue

and grey = yellow!!!!

So much easier when we all just keep to the L1=L1, L2=L2, L3=L3 as per Table 51..

Rather than

old L2 = new L3

old L3 = new L2.

Guinness

 

[Evans Electric]

Yeah Yeah,k tried that!Perhaps I'm just cursed! It never works for me!!!!

Do you know nuffin Paddler, if you do it at the motor it will always know and will then run the wrong way, what you have to do is creep up to the starter and do it there while its not looking.