# Soft Start 480 volt motor



## Metersocket648 (Feb 8, 2021)

we got a call and a customer mentioned that their motor will start up and as soon as the .otor gets switched over from Delta to Wye, it stops, no breakers trip, it just shuts down, we put in a nee soft start contactor, and the motor is fairly new, the voltage is 277/480, and it measures accordingly, no unbalanced loads, nothing, this is the third time I came back to this facility and the only other time anything was electrically upgraded was the 347/600v to 277/480 step down distribution transformer and that was a different electrician, idk if it has something to do with that particular transformer or what, but this facility is wired very weird. Any info on what could be the problem?


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## gpop (May 14, 2018)

Delta/Wye starting (which should be wye/delta) is a different beast from a soft-start so first we need to know which one is being used.

Does it have 3 contactors or does it have a soft-start (if its a soft-start does it have a main contactor, Does it have a bypass contactor, whats the brand name and model number).

we like pictures.


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## Metersocket648 (Feb 8, 2021)

gpop said:


> Delta/Wye starting (which should be wye/delta) is a different beast from a soft-start so first we need to know which one is being used.
> 
> Does it have 3 contactors or does it have a soft-start (if its a soft-start does it have a main contactor, Does it have a bypass contactor, whats the brand name and model number).
> 
> we like pictures.


Yes, wye/delta, its a RAM industries ABB 250 HP 480volt starter


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## Metersocket648 (Feb 8, 2021)

gpop said:


> Delta/Wye starting (which should be wye/delta) is a different beast from a soft-start so first we need to know which one is being used.
> 
> Does it have 3 contactors or does it have a soft-start (if its a soft-start does it have a main contactor, Does it have a bypass contactor, whats the brand name and model number).
> 
> we like pictures.


We pulled the cabinet out BTW cuz the dumbest who installed it connected it up to where it has to be moved


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## micromind (Aug 11, 2007)

Metersocket648 said:


> Yes, wye/delta, its a RAM industries ABB 250 HP 480volt starter
> View attachment 154764


The reason it doesn't work is because the line and motor are not connected..........lol.

What you have here is called a 'closed transition Y-∆ starter'.

If it failed after it was moved, the motor may have been connected wrong. It needs to be 6-4-5 ,1-2-3. Not 4-5-6, 1-2-3.

If it's connected wrong, it'll start in Y but when it switches to ∆, it'll short the motor windings and it'll likely stop suddenly or it might coast to a stop.


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## gpop (May 14, 2018)

You did check the physical overload block next to the main breaker is not tripped. Hard to tell in the picture but normally the CT's for the overloads are only on the leads going to the middle contactor. We do not use the overloads during starting but we do when we switch to run. If its tripped then it will not switch to run. (the 4th ct is used by the softstart and has both leads in the CT)


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## gpop (May 14, 2018)

Ammonia refrigeration compressor?


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## Metersocket648 (Feb 8, 2021)

micromind said:


> The reason it doesn't work is because the line and motor are not connected..........lol.
> 
> What you have here is called a 'closed transition Y-∆ starter'.
> 
> ...


We took it out after diagnosing it, now one of the guys in my crew said start at the transformer, I'd what the hell he was talking about


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## Metersocket648 (Feb 8, 2021)

gpop said:


> You did check the physical overload block next to the main breaker is not tripped. Hard to tell in the picture but normally the CT's for the overloads are only on the leads going to the middle contactor. We do not use the overloads during starting but we do when we switch to run. If its tripped then it will not switch to run. (the 4th ct is used by the softstart and has both leads in the CT)


It ain't tripped, everything looks fine, but in the end its gonna be something stupid


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## Metersocket648 (Feb 8, 2021)

gpop said:


> Ammonia refrigeration compressor?


Yep, at an ice skating rink, a big one too


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## gpop (May 14, 2018)

Metersocket648 said:


> It ain't tripped, everything looks fine, but in the end its gonna be something stupid


This isn't a job where look for a problem this is a job where you use a meter and test for the problem.

Understand what the parts do, The order parts are used and the safety's involved.

You were told to start at the transformer. well that's top right hand side of cabinet. does it have 480v going in (fuses) does it have 120v going out (fuses) does the label say its a 480v transformer.

Sequence of operation

1/ start oil pump (contactor left side)
2/ wait for timer left side above oil contactor (safety- oil pump must run so expect aux on contactor to control timer)
3/ Send run command to ABB controller (probably from timer)
4/ close large contactors 1 and 3 (1 - is a wye shorting contactor, Safety - mechanical and electrical interlock between contactor 1 and 2)
5/ ABB unit will now monitor the amps to the motor using single CT
6/ when amps start to drop abb will turn off contactor 1 and energize contactor 2. (Safety - mechanical and electrical interlock)

so up to 5 we pass but we fail at step 6

abb monitor does not like something and refuses to do step 6. read the manual (timed out and load did not drop)
contactor 2 did not close due due to tripped overload. Test with meter
contactor 2 did not close due to mechanical jam
contactor 2 did not close due to aux in contactor 1 (electrical interlock)
Contactor 2 did not close due to voltage drop on control circuit or it has a bad coil
contactor 2 did close but failed to show closed to abb unit (safety probably using the aux)

Power off the unit then test the Aux's on the contactors.(make sure its powered down) Manually cycle the contactors while testing aux's.
Ohm number 2 contactor coil.
open contactors and check contacts are not burn up. You should have 2 sets. One hits first and breaks last (will look rough) the second set take the load.and should look clean
Power up and set a mobile phone on record. Leave the room and have them try to start the unit. watch the video to see if 2 tries to close or if the abb controller flashes a led.
There are live tests that involve unplugging things, dropping the motor leads and using jumpers but i do not think you have the experience to do theses.


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## John Valdes (May 17, 2007)

Connecting this wye/delta config is very easy if you are using the same motor and you marked each lead before they were removed. Unless you move it to another source that is not phased exactly the same as the original phasing. (this is fairly easy to correct)
Connecting this wye/delta config can be difficult if you bring in a new motor or disconnect everything and not mark exactly where each wire goes. And like above the new location is not phased the same exact way.
I have found six lead wye/delta starting to be the most confusing connections to make for someone who does not understand how its supposed to work and hard for some that know how its supposed to work.
I cannot count the times when at the motor shop getting calls about connections after we re-wound their motor. You can find each motor coil (winding) and give each coil leads numbers. And we numbered the motor leads before it left the shop, but to assume you can just connect number for number is short sighted.


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## paulengr (Oct 8, 2017)

As others have said, make SURE the secondary leads are wired properly. Many will tell you that the leads go in a certain order and this is most certainly true but VERY easy to mess it up. First you need to identify the motor leads 1, 2, 3, 4, 5, 6, or in the case of a 12 lead motor it's a little more complicated. This isn't standard but when I wire one up, I tape the main contactor leads with one band of brown, orange, yellow. Convention says you use black red blue for 208-230 V but in this area (Carolinas, Virginia) I'd say that 99% of the 200 V class motors also get the brown/orange/yellow treatment. Plus if it's high leg delta you can't use black red blue anyways since the high leg must be orange by Code. Then I mark the secondary leads with two bands of brown, orange, yellow that belong to the same PHASE. So that means on 6 lead T1 gets 1 stripe brown, T6 gets 2 stripes brown, T2 gets one stripe orange, T4 gets 2 stripes orange, and so forth. I make pairs if you have multiple conductors per phase the same color scheme. If it hasn't been marked or you can't figure it out between the motor and starter, ohm everything out before you start. And unlike 3 lead setups if you need to reverse direction, you reverse both primary and secondary in the same way (convention is swap the browns and yellows). In the same setup if you ever switch over to an electronic soft starter then you just need to connect the browns to T1, the oranges to T2, and the yellows to T3. Everything is already "done" for you.

Now when it comes to checking the starter wiring there is an easy way to figure this out. Typically it's an open transition 3 contactor system. The 4 contactor system is slightly more complicated. Start with the wye contactor because it's easiest to spot...one side has 3 leads or bus bars tied together with no connection going anywhere. From the LOAD side of this contactor slide over to whichever contactor it is connected to. This is the delta contactor. The line side of that contactor is tied to the main contactor. If you want to you can even label them S (Start), R (run), and M (main).

Now next important detail is that the ORDER of the phases does NOT matter on the wye contactor. It's...wye. But it is very important in the delta (run) contactor and that's where the phase marking matters. Look at the LINE side of the contactors. Power (line side) should run to the main contactor and then gets jumpered to the run contactor). The jumpers can be ordered differently. Some guys like to wire it up so that the motor (load) side ends up T4, T5, T6 and others line it up so that it's T6, T4, T5 (line side phasing). The only way to tell is look how it is jumpered on the line side. Connect the secondary wires so that based on the line side you have brown to brown, orange to orange, and yellow to yellow based on the LINE side of the contactor and the phasing tape colors I mentioned earlier. This way no matter what order things go in, it can't get screwed up.

Also remember that if you want to reverse directions you MUST swap both sets of leads. It's not enough just to swap say T1 and T3. You must also swap the secondaries in the same way. Again phasing them to match the line side is the surest way to do it without making mistakes.

Finally, there are a TON of things that can go wrong when it comes to troubleshooting these things. Aside from the wiring, typically the start and run contactors are interlocked to each other (cross connected to their respective NC aux contacts) and mechanically interlocked. Also it's pretty common for the wye-delta timer relay to go bad either just contacts or the timer itself failing. So this is where you need to understand how it works and monitor votlages with a multimeter as it cycles because aux contacts are also notoriously unreliable. Also don't forget that contactors and coils can and do go bad. I've seen at least a couple times with the symptoms you describe where the run contactor fails simply because it swells up from a turn-to-turn short and quite literally locks itself in place so that the contactor CAN'T close as an example.

RAM Industries as far as I know or at least the facility was bought out by Schneider and is now used for assembling some stuff in the US. I don't know if RAM is still in business anywhere. Cost-wise these things are all getting very long in the tooth. If you replace the contactors with identical ones (old giant NEMA contactors) an electronic soft starter is far simpler and easily fits in the space that the wye delta contactor previously occupied with room to spare. I've done countless upgrades to compressors for food and ice plants. Takes about 4-5 hours. You just ditch the RAM display stuff, all the contactors, and all the extra relays. Demo everything back to just the control power transformer and the wiring. Mount the electronic soft start, plate over and install the new display on the door, and connect all the control wiring to the soft starter. As previously mentioned by the way you label the wiring, motor wiring is a piece of cake. Then program and off you go. For compressor starting select current limiting mode with a 5 second ramp time and start with 400% soft starting. On some I've gotten it to work with 350% and on others I've had to go as high as 500% to get it to start smoothly.


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## Metersocket648 (Feb 8, 2021)

paulengr said:


> As others have said, make SURE the secondary leads are wired properly. Many will tell you that the leads go in a certain order and this is most certainly true but VERY easy to mess it up. First you need to identify the motor leads 1, 2, 3, 4, 5, 6, or in the case of a 12 lead motor it's a little more complicated. This isn't standard but when I wire one up, I tape the main contactor leads with one band of brown, orange, yellow. Convention says you use black red blue for 208-230 V but in this area (Carolinas, Virginia) I'd say that 99% of the 200 V class motors also get the brown/orange/yellow treatment. Plus if it's high leg delta you can't use black red blue anyways since the high leg must be orange by Code. Then I mark the secondary leads with two bands of brown, orange, yellow that belong to the same PHASE. So that means on 6 lead T1 gets 1 stripe brown, T6 gets 2 stripes brown, T2 gets one stripe orange, T4 gets 2 stripes orange, and so forth. I make pairs if you have multiple conductors per phase the same color scheme. If it hasn't been marked or you can't figure it out between the motor and starter, ohm everything out before you start. And unlike 3 lead setups if you need to reverse direction, you reverse both primary and secondary in the same way (convention is swap the browns and yellows). In the same setup if you ever switch over to an electronic soft starter then you just need to connect the browns to T1, the oranges to T2, and the yellows to T3. Everything is already "done" for you.
> 
> Now when it comes to checking the starter wiring there is an easy way to figure this out. Typically it's an open transition 3 contactor system. The 4 contactor system is slightly more complicated. Start with the wye contactor because it's easiest to spot...one side has 3 leads or bus bars tied together with no connection going anywhere. From the LOAD side of this contactor slide over to whichever contactor it is connected to. This is the delta contactor. The line side of that contactor is tied to the main contactor. If you want to you can even label them S (Start), R (run), and M (main).
> 
> ...


It has fuses going in and coming out, it still reads voltage on the meter, then from there I checked my correct phasing, all good on both line, and load sides of the contactors, then i noticed the problem, like I said, something stupid, the capacitor, the thing was swollen. This is only my second time working on one other these, I've been looking into doing some industrial electrical for a short time, finally got with an industrial electrician and been doing resi, com, and ind, industrial is exciting


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## gpop (May 14, 2018)

Metersocket648 said:


> It has fuses going in and coming out, it still reads voltage on the meter, then from there I checked my correct phasing, all good on both line, and load sides of the contactors, then i noticed the problem, like I said, something stupid, the capacitor, the thing was swollen. This is only my second time working on one other these, I've been looking into doing some industrial electrical for a short time, finally got with an industrial electrician and been doing resi, com, and ind, industrial is exciting


The cap on the contactor coil caused it not to switch to delta with out blowing a fuse ?.


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## paulengr (Oct 8, 2017)

gpop said:


> The cap on the contactor coil caused it not to switch to delta with out blowing a fuse ?.


Good point. Only one way makes any sense to me. If the CPT is fairly closely sized and the control power fuse is fairly large or of the slow blow variety or there is only a fuse on the primary side of the CPT, and it uses a 3 wire start/stop circuit, the control voltage could be drawn down low enough to cause the contactors to open without tripping a fuse. Often that 2 A fuse gets replaced with whatever is in the bag such as a 10 A fuse and so it never trips.


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## gpop (May 14, 2018)

paulengr said:


> Good point. Only one way makes any sense to me. If the CPT is fairly closely sized and the control power fuse is fairly large or of the slow blow variety or there is only a fuse on the primary side of the CPT, and it uses a 3 wire start/stop circuit, the control voltage could be drawn down low enough to cause the contactors to open without tripping a fuse. Often that 2 A fuse gets replaced with whatever is in the bag such as a 10 A fuse and so it never trips.



Possible and it would neatly explain why the ABB controller has no memory of what went wrong (reboot clears faults). That's a big cpt so its going to have to be at least a 20 amp time delay fuse. 

Sometimes you think you have fixed the problem but with out testing you may have just got lucky and it will come back and bite you in the arse. I would test the cap for a short then check on the size of the fuse before i dare say it was fixed.


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## Metersocket648 (Feb 8, 2021)

gpop said:


> The cap on the contactor coil caused it not to switch to delta with out blowing a fuse ?.


They had 30 amp fuses instead of 20, I dont know who serviced this when the fuses were put in but they wanted a fire


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