How to connect motor?

[whazza22]

Hi there,

I have very little knowledge on motors as I have never really dealt with them, so im after some advice on how to connect a motor.

The motor is part of an Air Handling Unit with has 2 motors connected together via belts but only 1 running at any time.

One of the motors was faulty and has come back from repair and needs to be reconnected.

From the isolator, there are 6 cables labelled u1,u2,v1,v2,w1 and w2.

I can see all of those connections on the motor terminals but there are no links in place on the motor for star or delta (the lid shows where links go for star or delta)

Does the motor still need to have links in place or is that only when you have 3 cables?

Thanks

 

[Marvo]

It should be as simple as connecting you U1, of the supply to U1 on the motor and so on for the other five wires as well. If you have a six wire supply (seven wire with earth) from the isolator then you would not require any link in the motor terminal box......in fact if there are links you must remove them.

 

[whazza22]

Ok thankyou very much. Is that because the motor can run at low speed or high speed? (or am I completely wrong )

 

[Marvo]

The links are required if the motor is connected to a 3-wire direct on-line supply. With a 6 wire supply the motor is probably on a star-delta system or a speed controller and both of these arrangements don't need links.

Just to complicate matters it's possible to have a DOL motor supplied by six wires but the linking will already be done elsewhere in this case (maybe in the isolator or the control panel where the supply originates from) so extra links in the motor would have no purpose even in this scenario.

 

[benji]

Not enough info,6 wires from isolator do you mean from starter?or is the isolator a local isolator adj. motor?
2 motors linked by v-belts ,connect motor A the same as motor B then CHECK THAT ROTATION of both motors is the same BEFORE replacing v-belts.Can not stress that if you are not experienced enough you should seek assistance with this task.

 

[Knobhead]

As benji has said check the rotation first. A brand new motor you can more or less guarantee direction, rewinds……

 

[whazza22]

Yes, the 6 wires are coming from a local isolator next to the motor

 

[netblindpaul]

Whazza,
What is the motor control/starter?

 

[whazza22]

If the motor rotates in the wrong direction, do I still just swap any two phases? (would this need to be done with both sets of cables or the one?

 

[topquark]

If the motor rotates in the wrong direction, do I still just swap any two phases? (would this need to be done with both sets of cables or the one?

Yep, just swap two phases.

 

[netblindpaul]

topquark,
That depends on the starter!
If you just swap 2 phases (leads) at the motor and there is a Y/D starter then you could get a big bang!

 

[topquark]

If the motor is running backwards you have one of the three phase sequences in the left hand "table" connected to your motor terminals, swapping any two phases will give you either of the three resulting tables, the first table for swapping T1 and T2, the second T1 and T3, the third T2 and T3. From which you can see the phases then end up in the correct sequence.

[TABLE]
[TR]
[TD][B]Terminal[/B]
[/TD]
[TD="width: 27"][B]  T1[/B]
[/TD]
[TD="width: 27"][B]  T2[/B]
[/TD]
[TD="width: 27"][B]  T3[/B]
[/TD]
[TD="width: 86"][/TD]
[TD="width: 39"][B]  T1/2[/B]
[/TD]
[TD="width: 45"][/TD]
[TD="width: 42"][/TD]
[TD="width: 39"][/TD]
[TD="width: 39"][B]T1/3[/B]
[/TD]
[TD="width: 44"][/TD]
[TD="width: 42"][/TD]
[TD="width: 39"][/TD]
[TD="width: 39"][B]T2/3[/B]
[/TD]
[TD="width: 44"][/TD]
[TD="width: 45"][/TD]
[/TR]
[TR]
[TD][/TD]
[TD]3
[/TD]
[TD]2
[/TD]
[TD]1
[/TD]
[TD][/TD]
[TD]2
[/TD]
[TD]3
[/TD]
[TD]1
[/TD]
[TD][/TD]
[TD]1
[/TD]
[TD]2
[/TD]
[TD]3
[/TD]
[TD][/TD]
[TD]3
[/TD]
[TD]1
[/TD]
[TD]2
[/TD]
[/TR]
[TR]
[TD][/TD]
[TD]1
[/TD]
[TD]3
[/TD]
[TD]2
[/TD]
[TD][/TD]
[TD]3
[/TD]
[TD]1
[/TD]
[TD]2
[/TD]
[TD][/TD]
[TD]2
[/TD]
[TD]3
[/TD]
[TD]1
[/TD]
[TD][/TD]
[TD]1
[/TD]
[TD]2
[/TD]
[TD]3
[/TD]
[/TR]
[TR]
[TD][/TD]
[TD]2
[/TD]
[TD]1
[/TD]
[TD]3
[/TD]
[TD][/TD]
[TD]1
[/TD]
[TD]2
[/TD]
[TD]3
[/TD]
[TD][/TD]
[TD]3
[/TD]
[TD]1
[/TD]
[TD]2
[/TD]
[TD][/TD]
[TD]3
[/TD]
[TD]1
[/TD]
[TD]2
[/TD]
[/TR]
[/TABLE]

 

[netblindpaul]

topquark,
What if you have all 6 winding ends coming out of the motor mate.
I can't quite follow your table, sorry not your fault.
If you have winding 1, say U1 & U2, winding 2 V1 & V2, & winding 3 W1 & W2 all separate in the motor, swapping 2 will not help!

 

[whazza22]

On both sets of cables or just the one set? (I have 6 cables from isolator so 2 sets of 3 phases)

 

[topquark]

Sorry if it's missleading, I had thought the question was asking specifically about connection to the motor (as in the thread title and OP).

 

[netblindpaul]

topquark,
IF he has 6 leads from the iso then he probably has a Y/D starter on the end of it, but he has not yet told us.
If I found 6 leads my 1st thought would be Y/D and I would then look into this from there.
If you swap the ends of one pair of windings all you will do is reverse the field in that winding, not good.
If you swap the wrong pair, you could short 2 phases together almost.

 

[netblindpaul]

He is trying to connect the motor, sorry, but he has 6 wire ends to do it as I understand it.

 

[topquark]

He is trying to connect the motor, sorry, but he has 6 wire ends to do it as I understand it.

Ah sorry, I thought that was 6 leads for the two motors, not for the one.

 

[benji]

whazza are you saying you have connected the motor up and it,s going the wrong way or are you asking how to reverse the motor if it goes the wrong way, also where is the starter for the motor?

 

[silva.foxx]

The OP still hasn't stated whether the motor is two-speed or star-delta started.

With star-delta starting, changing the DoR requires a better understanding of the way its wired rather than just swapping phases. The phases have to be swapped in sets (to or at the motor) or on top of the line contactor. If swapped incorrectly, the motor may start in the DoR you require but may try to swap direction in the delta connection, not a good scenario really!

So... just be careful.

note to self: phases is incorrect term for lines L1, L2 & L3.

@ Whazza22... do you know whether you have two speed motor or star-delta starter? Which?

@ Tony... motor sticky... looking forward to that one.

regs// s.f

 

[Knobhead]

Sorry but what I'm planning will take time

 

[silva.foxx]

Sorry but what I'm planning will take time

Totally agree... finding that out with my App. program. I'll be developing motor starting stuff as part of that, along with VFDs and soft starts so I'll chuck a version your way... in time!

What I'm finding is that, although I hoard shed-loads of info, I have very little or close to zero orgainisation. My filing system over the years has been terrible. I think that's a valid resolution for the New Year!

Although we have the info... we still have to sift through it and collate what's relevant today.

Good luck T, and thanks for sharing.

 

[Knobhead]

Here’s how (a sneak preview)

View attachment 8303

 

[whazza22]

Reversing rotation of motor?

Hi all,

My previous post was a bit vague so I have included a photo to help explain.

http://s193.photobucket.com/albums/z53/whazza22/?action=view&current=Motor.png

Basically I would like to know how to reverse the rotation of the motor. I know you swap any two phases on a 3 phase motor with just 3 cables but how do you do it for a motor that has 2 sets of connections (6 cables)

The two motors are fed from a 3 phase isolator and are for the two supply fans on an Air Handling Unit, with only one running at any time.

Would you swap two phases on one set or on both or something totally different lol

Much appreciated

 

[JD6400]

Re: Reversing rotation of motor?

I think you mean you have a star / delta motor , if so you should have three interlinked contactors ?
If so just swap two phase's that are on the incoming side of the first contactor .

 

[topquark]

Re: Reversing rotation of motor?

The difference in this case is that for each phase you have two connections to a winding and they must be paired correctly and both swapped together.

 

[silva.foxx]

Re: Reversing rotation of motor?

Ideally... you should continue your original thread on this same topic to keep continuity.

If your brown wires are switched from L1 and your black wires from L2 then your diagram doesn't make sense, unless:

(A) you have the labelling of the motor terminals incorrect, or

(B) you have something else "within" the box that you depict as the 'isolator'.

It would perhaps make sense if you had U1, V1 and W1 on the left of the motor terminal block with W2, U2 and V2 on the right of the terminal block, assuming the six wires are identically paired through the isolator. Please check this.

I know you are making a great effort in having us understand your plight but you must understand we cannot see what you have.

What's happening in the isolator. Is there 3 phase into the top of the isolator?

Are you certain it's an isolator as opposed to some form pole-reversing switch?

The six wires to the load... are they paired-up in the bottom of the 'isolator'?

 

[whazza22]

Re: Reversing rotation of motor?

Ideally... you should continue your original thread on this same topic to keep continuity.

If your brown wires are switched from L1 and your black wires from L2 then your diagram doesn't make sense, unless:

(A) you have the labelling of the motor terminals incorrect, or

(B) you have something else "within" the box that you depict as the 'isolator'.

It would perhaps make sense if you had U1, V1 and W1 on the left of the motor terminal block with W2, U2 and V2 on the right of the terminal block, assuming the six wires are identically paired through the isolator. Please check this.

I know you are making a great effort in having us understand your plight but you must understand we cannot see what you have.

What's happening in the isolator. Is there 3 phase into the top of the isolator?

Are you certain it's an isolator as opposed to some form pole-reversing switch?

The six wires to the load... are they paired-up in the bottom of the 'isolator'?

Yes its definately a 3 phase isolator with 3 phases going in the top.

Also the terminals are labelled correctly on the motor and I confirmed this by looking at the connections on the 2nd motor which is working fine.

I will be connecting the 2nd motor which has been repaired and sometimes they are re-wound the opposite way from before.

 

[Guest123]

Threads Merged.

Please keep to one thread.

Thank you.

 

[whazza22]

I have managed to look at the isolator and it has a 3 phase supply at the top, and on the outgoing side it has between 8 to 12 terminals. All of the outgoing cables are in different terminals which are numbered.

Any ideas?

Thanks

 

[netblindpaul]

Is this a change over isolator, does it feed both motors, is it just an isolator?
Pics?

 

[whazza22]

It looks like a normal 3 phase isolator with the feed going in top and the outgoing from bottom. The only difference is that it has loads of terminals on bottom. It feeds one motor but have 6 outgoing cables

 

[Marvo]

Pictures would be very helpful if you could attach a few of the isolator and motor terminal box and even the supply where it comes from the control panel along with the contactor/overload arrangement.

 

[netblindpaul]

It could be a manual Y/D starter (manual change over) switch.
Have you opened up "the box"?

If it is what i think it is, then it probably does not comply with legislation now, & no I don't mean BS7671.

Without more info then there is no more I can suggest, sorry.

 

[whazza22]

The casing is clear so you can see the switch and terminals. It is just an on or off switch. I have no photos at moment

 

[JD6400]

It could be a manual Y/D starter (manual change over) switch.
Have you opened up "the box"?

If it is what i think it is, then it probably does not comply with legislation now, & no I don't mean BS7671.

Without more info then there is no more I can suggest, sorry.

What are they in contravention of , we look after several grain stores that still have these on the main fans ?

 

[benji]

The problem is we don,t no what this isolator/starter is, no photo,no manufacturer type/series and were on page 4 . If we can,t definitive info we might as well get a mini bus and go down and have a look

 

[netblindpaul]

PUWER98 as a start, possibly others depending on the way the fans are wired.

 

[netblindpaul]

Quite benji!
Trouble is the round Robin minibus fuel would probably be more than the OP paying for someone competent to sort it for him!

 

[Knobhead]

we might as well get a mini bus and go down and have a look

Now that sounds a bloody good idea. Who’s driving the bus? The Electro-bus-ters team arrive en mass. To drunk to see what we're doing but we’ll muddle through somehow.

 

[topquark]

Is there a bar on the bus (you can see where this is going )?

 

[netblindpaul]

I like where this is going, as long as someone else is picking up the bill! :yes:

 

[topquark]

... and of course a big trunk for our tools in the bus, then we can have bus bar trunk in

 

[Marvo]

... and of course a big trunk for our tools in the bus, then we can have bus bar trunk in

*groan*

 

[Knobhead]

**** that I want an failsafe UPS beer supply to the Bus, operation of the bus switches only to be undertaken by by sober authorised persons, (that’s ****** that idea up), When we reach county borders the supply system swaps to the local (frequency) brew.

I can see this ending in a muddy ditch at the side of a field!