# Wye Start - Delta Run



## frenchelectrican

triden said:


> Have a 100HP wye-delta motor (575vac, 3ph). Is there a way that you can start this thing without a wye-delta starter, or is it even recommended? If I could just forget about the wye winding and hook a soft start up to the delta winding, that would be nice.


I done that pretty often just hook it up in delta connecton and start DOL ( direct on line ) but the only quirk with this size some of the system may not handle the inrush current when you crank it up.

Most electricians will go with soft start and keep it in delta set up and go from there. ( more smoother starting on soft start than Y-D starter will do. )

costwise I think it is cheaper to get soft start than Y-D starter. espcally with that big of motor size.


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## triden

frenchelectrican said:


> I done that pretty often just hook it up in delta connecton and start DOL ( direct on line ) but the only quirk with this size some of the system may not handle the inrush current when you crank it up.
> 
> Most electricians will go with soft start and keep it in delta set up and go from there. ( more smoother starting on soft start than Y-D starter will do. )
> 
> costwise I think it is cheaper to get soft start than Y-D starter. espcally with that big of motor size.


Out of curiosity will a standard 100hp DOL starter fire this thing up using just the delta winding?


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## frenchelectrican

triden said:


> Out of curiosity will a standard 100hp DOL starter fire this thing up using just the delta winding?


Yep because Delta is a running connection on the motor. 

but if that motor is started unloaded ( nothing on the motor ) it not too bad but loaded start that depending on what kind of load it will start.

Compressors is the toughest one to start escpally loaded heads. ditto with high intera loads too.

Just keep in your mind the DOL inrush starting current typically about 6X to 8X of running amps of your motor. so it may affect the system somehow escpally with small POCO transfomer.


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## emtnut

triden said:


> Have a 100HP wye-delta motor (575vac, 3ph). Is there a way that you can start this thing without a wye-delta starter, or is it even recommended? If I could just forget about the wye winding and hook a soft start up to the delta winding, that would be nice.


To hook up a soft start would be no problem.
It's generally cheaper to go with wye-delta start if the motor supports it. I only ever used a soft start with delta only motors.

You also mentioned DOL start. 100hp is a large motor to start that way !
Depends on the initial load as FrenchElectrician mentioned. Generally that would cause demand peaks, and Hydro would penalize you for that !
Also it is hard on the motor if started under any significant load.

Given the motor, what's the reason for not going with wye start ?


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## Cow

triden said:


> Have a 100HP wye-delta motor (575vac, 3ph). Is there a way that you can start this thing without a wye-delta starter, or is it even recommended? If I could just forget about the wye winding and hook a soft start up to the delta winding, that would be nice.


I've had several part wind start motors to connect over the years. I've yet to actually wire one that way though.

They've always been wired across the line, with a soft start or a VFD. So it can be done. 

Depending on your application, it could be any one of those three options above. 100HP is not out of line for across the line start, but what it's driving as well as what the power company thinks also plays a part.


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## micromind

This motor will be perfectly happy to be started across the lines or with a soft-start. Just connect it ∆.

If it's 6 leads, the ∆ connection would be L1 = T1&T6, L2 = T2&T4, L3 = T3&T5. 

Starting a 100HP motor across the lines is somewhat common here especially in a fair-size industrial facility. 

The starting current of a 100HP 575 volt motor will be around 600 amps.


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## triden

emtnut said:


> To hook up a soft start would be no problem.
> It's generally cheaper to go with wye-delta start if the motor supports it. I only ever used a soft start with delta only motors.
> 
> You also mentioned DOL start. 100hp is a large motor to start that way !
> Depends on the initial load as FrenchElectrician mentioned. Generally that would cause demand peaks, and Hydro would penalize you for that !
> Also it is hard on the motor if started under any significant load.
> 
> Given the motor, what's the reason for not going with wye start ?


It's an interesting situation and I'm not the guy directly wiring it. Motor was supplied by an irrigation distributor and starter was found at a salvage yard and came off an old conveyor system. 

They were having a bear starting the motor so they got me to have a look at it which is when I thought it was a wye-delta. They initially screwed up the wiring and hooked the start and run windings together which kept blowing the breaker. I just thought it would be easier to put in a soft start instead of a wye-deta starter as I wasn't sure of their availability.


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## triden

micromind said:


> This motor will be perfectly happy to be started across the lines or with a soft-start. Just connect it ∆.
> 
> If it's 6 leads, the ∆ connection would be L1 = T1&T6, L2 = T2&T4, L3 = T3&T5.
> 
> Starting a 100HP motor across the lines is somewhat common here especially in a fair-size industrial facility.
> 
> The starting current of a 100HP 575 volt motor will be around 600 amps.


It's a 6 lead. Wiring diagram is slightly different than what you mention. Baldor Reliant Super E. If we wired it wye-delta, we would have to run another cable - not happening on this one.

End suction centrifugal pump so luckily low starting torque.


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## frenchelectrican

Ya can get Y-D starter but it will take longer to get it espcally that size of motor.

the VSD or soft start is more common on this apps. 

If i remember that motor in that size typically only have 6 leads on Y-D so just wired it in delta but look at nameplate to make sure you snatch the correct conductors. I just have one Y-D motor not too long ago but what really compound it was a dual voltage motor so end up with 12 leads !!  no nameplate diagram on it but good thing I save my notebook on connection diagram that help me a bit.


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## frenchelectrican

triden said:


> It's a 6 lead. Wiring diagram is slightly different than what you mention. Baldor Reliant Super E. If we wired it wye-delta, we would have to run another cable - not happening on this one.
> 
> End suction centrifugal pump so luckily low starting torque.


That is double parallel delta connection I have see it before.


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## triden

frenchelectrican said:


> That is double parallel delta connection I have see it before.


hmm you're right! That's a new one for me. I imagine it serves the same purpose of a Y-D?

http://www.usmotors.com/TechDocs/ProFacts/Starting-Methods/Double-Delta


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## frenchelectrican

triden said:


> hmm you're right! That's a new one for me. I imagine it serves the same purpose of a Y-D?


Ya that what it was .,, but just a tweak in the contractors so first bank engerized as soon the motor is up running speed second contractor kick in so it is in running mode.

I am assuming here if that is double delta it start at 50% HP/ TQ then near full running speed it kick in second set of delta to get full 100% of HP/TQ 

senice you mention centrifugal pump I would just hook it in run fashion. and use the VSD or soft start to throttle back the start up speed. that will start pretty fast. that part you have to watch out on discharge side.


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## micromind

triden said:


> It's a 6 lead. Wiring diagram is slightly different than what you mention. Baldor Reliant Super E. If we wired it wye-delta, we would have to run another cable - not happening on this one.
> 
> End suction centrifugal pump so luckily low starting torque.


That motor is not a Y - ∆, it is designed for part-winding start. It'll work fine being started across the lines or with a soft-start but not with a Y - ∆ starter. 

A 6 lead Y - ∆ motor has leads numbered 1, 2, 3, 4, 5, and 6. 

Use the run connection for across the lines starting or with a soft-start.


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## JRaef

micromind said:


> That motor is not a Y - ∆, it is designed for part-winding start. It'll work fine being started across the lines or with a soft-start but not with a Y - ∆ starter.
> 
> A 6 lead Y - ∆ motor has leads numbered 1, 2, 3, 4, 5, and 6.
> 
> Use the run connection for across the lines starting or with a soft-start.


Beat me to it...

Wye-Delta starter was the wrong thing all along for that motor, was never going to work. Any soft starter will do, especially for a centrifugal pump, but I would steer clear of the super cheap ones that only have SCRs on two of the three phases (the third pole is a piece of bus bar internally), they are not good for the motor and run a risk of frying it. If you are not sure, ask to see a diagram of what it looks like inside.

Bad:









Good:









Also if you are going to use a non-vented box, get a soft starter with a bypass contactor, or add one.


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## triden

Getting this information second hand: 

"Hooked it up today on the run winding. Applied power. Motor just sits there and hums, locked rotor drawing 200 amps. (seems low). Hooked up to the start winding, motor spins, draws about 50 amps and then about 2 seconds later jumps up to 200 amps. Won't spin on the run winding."

I'm thinking there's too much voltage drop at the motor. Getting him to take voltage measurements tomorrow. He's saying it's a 2400ft feed! He's got 500 MCM AL in the ground. Might be too much of a vdip to get spinning. I'll report back.


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## telsa

triden said:


> Getting this information second hand:
> 
> "Hooked it up today on the run winding. Applied power. Motor just sits there and hums, locked rotor drawing 200 amps. (seems low). Hooked up to the start winding, motor spins, draws about 50 amps and then about 2 seconds later jumps up to 200 amps. Won't spin on the run winding."
> 
> I'm thinking there's too much voltage drop at the motor. Getting him to take voltage measurements tomorrow. He's saying it's a 2400ft feed! He's got 500 MCM AL in the ground. Might be too much of a vdip to get spinning. I'll report back.


This is worse than homework.


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## frenchelectrican

triden said:


> Getting this information second hand:
> 
> "Hooked it up today on the run winding. Applied power. Motor just sits there and hums, locked rotor drawing 200 amps. (seems low). Hooked up to the start winding, motor spins, draws about 50 amps and then about 2 seconds later jumps up to 200 amps. Won't spin on the run winding."
> 
> I'm thinking there's too much voltage drop at the motor. Getting him to take voltage measurements tomorrow. He's saying it's a 2400ft feed! He's got 500 MCM AL in the ground. Might be too much of a vdip to get spinning. I'll report back.


Did ya say 2400 feet ?? that heckva a distance for 500 Kcm conductors. I will come up with some figures for proper conductor size..


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## frenchelectrican

I came up some figures but for 100 hp motor @ 575 volts at 2400 feet you denfendly need 800 KCM copper or 1000 KCM alum for that distance. 

I am thinking the exsting cable you got there is pretty much toasted espcally with alum conductor underground once you get a pinhole one of them ya are toasted., 

someone will have to pony up the cost for upsizing the exsting set or ask POCO to bury the primary and slap a padmount transfomer near the load.


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## micromind

Sending 200 amps to a motor connected to a close-coupled pump will make the motor turn, maybe not full speed but it'll turn. 

When power was applied to the start, 50 amps is really low. 2 seconds would be about right for the starter to bring the second set of windings in, hence the jump to 200 amps. 

Is the source actually 575? I'm beginning to wonder if it's 208. 

I'm also thinking that when they tried to start it Y-∆, they might have burnt it up. 

Part-winding motors don't do well with only one set of windings energized for more than a few seconds and even worse with the other set shorted as they would be with a Y-∆ starter.


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## frenchelectrican

micromind said:


> Sending 200 amps to a motor connected to a close-coupled pump will make the motor turn, maybe not full speed but it'll turn.
> 
> When power was applied to the start, 50 amps is really low. 2 seconds would be about right for the starter to bring the second set of windings in, hence the jump to 200 amps.
> 
> Is the source actually 575? I'm beginning to wonder if it's 208.
> 
> I'm also thinking that when they tried to start it Y-∆, they might have burnt it up.
> 
> Part-winding motors don't do well with only one set of windings energized for more than a few seconds and even worse with the other set shorted as they would be with a Y-∆ starter.


Most of PW ( part windings ) genrally limit about 3 to 5 seconds the most on one set of winding before it get hot 

that is the other thing I do not know if the OP's crew verify the supply voltage unloaded to make sure it is correct supply due the OP in Canada so I kinda expect to see 600 volts system is kinda common up there but ya some 480 volts is there. 
208 volts .,, humm ya that can be a possibltiy too. 


I am thinking someone been eating sour cherry on this one.,,


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## triden

micromind said:


> Sending 200 amps to a motor connected to a close-coupled pump will make the motor turn, maybe not full speed but it'll turn.
> 
> When power was applied to the start, 50 amps is really low. 2 seconds would be about right for the starter to bring the second set of windings in, hence the jump to 200 amps.
> 
> Is the source actually 575? I'm beginning to wonder if it's 208.
> 
> I'm also thinking that when they tried to start it Y-∆, they might have burnt it up.
> 
> Part-winding motors don't do well with only one set of windings energized for more than a few seconds and even worse with the other set shorted as they would be with a Y-∆ starter.


It's 575 vac. The starter they found is just a regular NEMA style 3 phase contactor. They initially hooked the start and the run windings together and popped the breaker a few times before they realized their error. Yesterday they tried to start it just on the run winding but it wouldn't spin - it just sat humming and drew ~200 amps. The cable is 2500 feet long which may be the problem. He's going to take some voltage measurements this morning at the motor to make sure it's not dropping too badly when he's trying to start it.


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## frenchelectrican

triden said:


> It's 575 vac. The starter they found is just a regular NEMA style 3 phase contactor. They initially hooked the start and the run windings together and popped the breaker a few times before they realized their error. Yesterday they tried to start it just on the run winding but it wouldn't spin - it just sat humming and drew ~200 amps. The cable is 2500 feet long which may be the problem. He's going to take some voltage measurements this morning at the motor to make sure it's not dropping too badly when he's trying to start it.


I been wondering about this part .,,

did your guys did try to megger the motor to make sure it is not being damaged interally ? 

I would run that megger test before you get too far with it because you mention breaker popped few time so I am assuming something got damaged to the motor inside.

Get the voltage reading unloaded and loaded ( when you try to start the motor ) and see how much voltage it drop. 

unless the motor was rewounded before and the motor shop did not update the info on the nameplate.,, this part I only guessing if that was done before.

let us know the situation what is going on .,,


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## triden

How embarrassing - he had the current limit on the breaker set too low. Wired both windings back up and turned the dial on the breaker and she runs. Drawing about 30 amps with no load on it.

Luckily we didn't have to take any drastic measures to get this thing working.


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## LATTC123

Hello Guys, Need your help with this Westinghouse 25Hp 286-U frame motor. I don’t understand how to set this motor up for wye start and delta run. So , for low voltage L1,T1,T7,T6 ...... L2,T2, T8, T4 .... L3,T3, T9, T5 connect and for high voltage L1-T1... T7-T4... L2-T2...T8-T5...L3-T3... T6-T9
MY VOLTAGE SOURCE IS 240V Three phase. 

There are 12 leads coming out of the motor. Believe me I’m scratching my head that T10, T11, T12 aren’t connected internally and that they aren’t listed on the nameplate.


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## LATTC123

Hello Guys, Need your help with this Westinghouse 25Hp 286-U frame motor. I don’t understand how to set this motor up for wye start and delta run. So , for low voltage L1,T1,T7,T6 ...... L2,T2, T8, T4 .... L3,T3, T9, T5 connect and for high voltage L1-T1... T7-T4... L2-T2...T8-T5...L3-T3... T6-T9
MY VOLTAGE SOURCE IS 240V Three phase. I’m opened to using the high voltage connection if I can’t use wye start and delta run for my low voltage connection

There are 12 leads coming out of the motor. Believe me I’m scratching my head that T10, T11, T12 aren’t connected internally and that they aren’t listed on the nameplate. Also why would L1,T1 & T7 connect with T6.


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## micromind

If you're using a Y-∆ starter, there will be 3 contactors. One will be by itself, the other 2 will be close to each other and also be electrically and mechanically interlocked. Only one of these 2 will have load terminals. 

The motor lead connections are as follows; 

On the single contractor, L1 = T1 & T7. L2 = T2 & T8. L3 = T3 & T9. 

On the double contractor, L1 = T6 & T12. L2 = T4 & T10. L3 = T5 & T11. 

Obviously, you'll need 6 wires from the motor to the starter (plus the ground) and each wire needs to be sized at 58% of the full-load current of the motor.

If you're starting it across the lines (full voltage) then you'll need 3 wires from the starter to the motor (plus the ground) and the connections are L1 = T1, T6, T7 & T12. L2 = T2, T4, T8 & T10. L3 = T3, T5, T9 & T11.


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## LATTC123

Thanks Micromind for your help, just a quick question. WHY DOES THE MOTOR NAMEPLATE NOT SHOW T10, T11, and T12. Is that normal, considering that the motor has 12 leads coming out of it?


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## frenchelectrican

LATTC123 said:


> Thanks Micromind for your help, just a quick question. WHY DOES THE MOTOR NAMEPLATE NOT SHOW T10, T11, and T12. Is that normal, considering that the motor has 12 leads coming out of it?


Here the diagram of NEMA motor Y-D connection look like.,,

Note: the T10 & T11 & T12 is joined only on wye during starting mode and some motors the three part is inside of the motor junction box. You should able find it.


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## micromind

LATTC123 said:


> Thanks Micromind for your help, just a quick question. WHY DOES THE MOTOR NAMEPLATE NOT SHOW T10, T11, and T12. Is that normal, considering that the motor has 12 leads coming out of it?


It might have been rewound and the shop brought all 12 leads out. 

If it was originally a 9 lead ∆, 1 was spliced internally to 12, 2 to 10 and 3 to 11. 

In this case, often 1, 2 and 3 will be larger wire because they have twice the current as the other 6 leads. In my experience, Emerson (US Electrical Motors) usually increases the size of 1,2 and 3; Baldor sometimes does but not all the time. Most other manufacturers will bring all 12 leads out on frame sizes 254 and larger. 

If all 12 leads are brought out, they will be the same size.


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## John Valdes

Guys. Download this and keep it. http://www.goevans.com/filesSite/EHB_pgs0803.pdf


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## JRaef

John Valdes said:


> Guys. Download this and keep it. http://www.goevans.com/filesSite/EHB_pgs0803.pdf


As I'm sure you know John, there was a day when you could walk into any decent motor shop or industrially oriented electrical wholesaler and get a free copy of that EASA Electrical Engineering Pocket Handbook with the name of that motor shop or supplier on the cover. I have a dozen or so scattered around my various work areas" (office desk, office workbench, home office desk, home shop, garage, bathroom...) 








Lately, they are a rare find at suppliers, as are all manner of printed material... :sad::vs_poop:


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## goodtimesgladly

Total insanity to run DOL in this day and age. Too much stress on moving parts. You can run a soft starter with inside the delta connection. This will allow you to use 1/2 the size of the soft starter cutting in half the cost of the starter. So you can start this 100 hp motor on a 50 hp soft starter. Please read the following link

https://rockwellautomation.custhelp.com/ci/fattach/get/12453/1200322872

The only advantage of running a VFD is if you want to reduce the rpm of the pump and thus saving power.


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## John Valdes

JRaef said:


> As I'm sure you know John, there was a day when you could walk into any decent motor shop or industrially oriented electrical wholesaler and get a free copy of that EASA Electrical Engineering Pocket Handbook with the name of that motor shop or supplier on the cover. I have a dozen or so scattered around my various work areas" (office desk, office workbench, home office desk, home shop, garage, bathroom...)
> 
> 
> 
> 
> 
> 
> 
> 
> Lately, they are a rare find at suppliers, as are all manner of printed material... :sad::vs_poop:


The reason is they are not free to the distributor or shop.
I handed them out like candy and the same with the little pocket screwdrivers when I first started in sales.
But the cost does add up when using these on cold calls. Had to be smart about it.

I also spent way to much money taking people to lunch.
I didn't take me long to know who were the free lunch whores and who I 
really should take out to lunch.
It got to the point I was having to pay for my own lunch more often than not, as I was by myself. 
You know.

One time I ran into a couple guys at the restaurant I had been trying to get in with. Before I knew it, there were 6-7 guys from the plant sitting at my table. What do you do then.


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## JRaef

John Valdes said:


> The reason is they are not free to the distributor or shop.
> I handed them out like candy and the same with the little pocket screwdrivers when I first started in sales.
> But the cost does add up when using these on cold calls. Had to be smart about it.
> 
> I also spent way to much money taking people to lunch.
> I didn't take me long to know who were the free lunch whores and who I
> really should take out to lunch.
> It got to the point I was having to pay for my own lunch more often than not, as I was by myself.
> You know.
> 
> One time I ran into a couple guys at the restaurant I had been trying to get in with. Before I knew it, there were 6-7 guys from the plant sitting at my table. What do you do then.


I do know about the lunch thing. I do a lot of "Lunch and Learns" at consulting firms and invariably, I get 20 people showing up for the lunch, then 17 of them leave during the "learn"... Still, it's the only way to get attention sometimes and as long as the 3 who stay are the right three, it's worth it.

I just saw that although those little books are $6.50 each to EASA members, but if you buy 1,000 of them imprinted with your name, they are only $1.99 each. But still, investing $2K in giveaways is not as easy to get past the bean counters as it used to be...


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## John Valdes

JRaef said:


> I do know about the lunch thing. I do a lot of "Lunch and Learns" at consulting firms and invariably, I get 20 people showing up for the lunch, then 17 of them leave during the "learn"... Still, it's the only way to get attention sometimes and as long as the 3 who stay are the right three, it's worth it.
> 
> I just saw that although those little books are $6.50 each to EASA members, but if you buy 1,000 of them imprinted with your name, they are only $1.99 each. But still, investing $2K in giveaways is not as easy to get past the bean counters as it used to be...


Amen JRaef!
I had no idea they had gone up so much. I could see me being very stingy with a $6.50 charge for each one.


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## goodtimesgladly

DOL is never a good idea in my opinion.
You can use a 50 HP soft starter to start this 100 HP motor wired inside the Delta
Here is a link but there are several soft starters that will work

https://rockwellautomation.custhelp.com/ci/fattach/get/12453/1200322872


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## goodtimesgladly

sorry for the double post loosing my mind


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## frenchelectrican

goodtimesgladly said:


> DOL is never a good idea in my opinion.
> You can use a 50 HP soft starter to start this 100 HP motor wired inside the Delta
> Here is a link but there are several soft starters that will work
> 
> https://rockwellautomation.custhelp.com/ci/fattach/get/12453/1200322872


Ya that can work but only with IEC connection and NEMA motors are not really directally comapareable with IEC system.

that is the only quirk you have to be aware of it.


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## JRaef

goodtimesgladly said:


> DOL is never a good idea in my opinion.
> You can use a 50 HP soft starter to start this 100 HP motor wired inside the Delta
> Here is a link but there are several soft starters that will work
> 
> https://rockwellautomation.custhelp.com/ci/fattach/get/12453/1200322872





frenchelectrican said:


> Ya that can work but only with IEC connection and NEMA motors are not really directally comapareable with IEC system.
> 
> that is the only quirk you have to be aware of it.


If people have a hard time with properly connecting a regular Wye-Delta starter, then an "Inside the Delta" connection of a Soft Starter is a worse idea... One wiring error and you lose both the soft starter and the motor.

Also, "Inside the Delta" is in my opinion a bad risk. If just one SCR shorts, there is no way to stop current flow to one winding of the motor, other than the circuit breaker and in a lot of cases, that will not trip until AFTER the motor is fried. In a normal soft starter that is "Line Connected, you would need to have at least _TWO _SCRs short in adjacent phases for that to happen, but that's rare. I never recommend them, even though my company sells them...


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## goodtimesgladly

JRaef said:


> If people have a hard time with properly connecting a regular Wye-Delta starter, then an "Inside the Delta" connection of a Soft Starter is a worse idea... One wiring error and you lose both the soft starter and the motor.
> 
> Also, "Inside the Delta" is in my opinion a bad risk. If just one SCR shorts, there is no way to stop current flow to one winding of the motor, other than the circuit breaker and in a lot of cases, that will not trip until AFTER the motor is fried. In a normal soft starter that is "Line Connected, you would need to have at least _TWO _SCRs short in adjacent phases for that to happen, but that's rare. I never recommend them, even though my company sells them...


I see your point and I do not know if and electronic overload (such as Allen Bradley E1 Plus) will protect the motor. They claim they will. This Electronic AB overload is supposed to sense single phasing and immediately drop out instead of waiting for the heaters to get hot then open. My experience is that SCR's do not take much abuse so your point is again well taken. It just seemed to be a cool idea having a 50 hp soft starter running a 100 hp motor. Too bad we can not do that with all motors. I am not a believer in DOL starting. Too much wear and tear on the moving parts which is why I only use soft starters or VFD's in my operation anywhere from 1/2 hp to 250 hp. Soft starters have come down in price in the past few years but also pay for themselves in reduced wear on system components.
Appreciate the info.


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## micromind

I'm just the opposite......I will install across-the-line starters whenever I can. 

The vast majority of stuff I work on can easily stand a quick start and a basic NEMA starter is incredibly simple to install and troubleshoot. 

I also greatly prefer the heater type O/Ls to the electronic ones. 

Call me 'old school' if you want, but I've seen too much electronic stuff fail where basic electromechanical most likely would have held.


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## frenchelectrican

micromind said:


> I'm just the opposite......I will install across-the-line starters whenever I can.
> 
> The vast majority of stuff I work on can easily stand a quick start and a basic NEMA starter is incredibly simple to install and troubleshoot.
> 
> I also greatly prefer the heater type O/Ls to the electronic ones.
> 
> Call me 'old school' if you want, but I've seen too much electronic stuff fail where basic electromechanical most likely would have held.


I am basically simuair to Micromind with the set up.,

I used the DOL ( across the line start ) much as I can as long the building electrical system can handle it. 

I like to keep it simple much as I can due you can do the trouble shooting faster.

very few super large motor will have either part winding or wye delta starting system beside the autotransfomer starter ( that is it own game on that .,,) 

But I can use the VSD or Soft start only if that equiment need it typically super high intera loads then yes I use that.


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## paulengr

goodtimesgladly said:


> I see your point and I do not know if and electronic overload (such as Allen Bradley E1 Plus) will protect the motor. They claim they will. This Electronic AB overload is supposed to sense single phasing and immediately drop out instead of waiting for the heaters to get hot then open. My experience is that SCR's do not take much abuse so your point is again well taken. It just seemed to be a cool idea having a 50 hp soft starter running a 100 hp motor. Too bad we can not do that with all motors. I am not a believer in DOL starting. Too much wear and tear on the moving parts which is why I only use soft starters or VFD's in my operation anywhere from 1/2 hp to 250 hp. Soft starters have come down in price in the past few years but also pay for themselves in reduced wear on system components.
> Appreciate the info.


The relay will trip so that's not really a problem. If the voltage on the SCR exceeds what is effectively the avalanche point if you think of it as a diode, it self commutates...basically it starts conducting regardless of what the gate is doing or did. The voltage at which this occurs is also reduced if the voltage has a sharp increase (dv/dt). This is why all soft starters have or need both snubbers (little RC or LC circuits clipped to the sides of the rails) and surge arresters (MOV's). What you are doing pretty much bypasses that protection.

Going with the protection idea though, FUJI and ABB both make some reasonably priced breakers that support a cheap little shunt trip module. This allows you to send a trip command to an external breaker in the event of a fault and shut everything down. I've seen it on several soft starters of this design. But as you said...the cost difference is so miniscule that by the time you spend all this extra money to try to make a goofy delta-wye soft starter, you could just as well buy the bigger soft start and just wire the motor up for full voltage all the time, and buy a 3 or 9 lead motor next time and save the extra cost of the 6 or 12.


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## paulengr

John Valdes said:


> The reason is they are not free to the distributor or shop.
> I handed them out like candy and the same with the little pocket screwdrivers when I first started in sales.
> But the cost does add up when using these on cold calls. Had to be smart about it.
> 
> I also spent way to much money taking people to lunch.
> I didn't take me long to know who were the free lunch whores and who I
> really should take out to lunch.
> It got to the point I was having to pay for my own lunch more often than not, as I was by myself.
> You know.
> 
> One time I ran into a couple guys at the restaurant I had been trying to get in with. Before I knew it, there were 6-7 guys from the plant sitting at my table. What do you do then.


I still give them out. I have a half dozen in the truck right now along with the mechanical one. If you're in the Carolinas or Virginia PM me and I'll hook you up no problem. That book does not have the 12 lead delta-wye starter configuration in it. We just had to look up and solve this one about 6 months ago at a deli meat plant so we had to look it up. It does have the 6 lead version, and some variations showing other things but not that one unless we missed it. Two of us were looking.


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## John Valdes

paulengr said:


> I still give them out. I have a half dozen in the truck right now along with the mechanical one. If you're in the Carolinas or Virginia PM me and I'll hook you up no problem. That book does not have the 12 lead delta-wye starter configuration in it. We just had to look up and solve this one about 6 months ago at a deli meat plant so we had to look it up. It does have the 6 lead version, and some variations showing other things but not that one unless we missed it. Two of us were looking.


A 12 lead motor is still a wye/delta connected so why would you need a special drawing or have to look it up?
The wye and delta connections are on the motor.
The starter config is exactly the same as the six lead.


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## paulengr

micromind said:


> I'm just the opposite......I will install across-the-line starters whenever I can.
> 
> The vast majority of stuff I work on can easily stand a quick start and a basic NEMA starter is incredibly simple to install and troubleshoot.
> 
> I also greatly prefer the heater type O/Ls to the electronic ones.
> 
> Call me 'old school' if you want, but I've seen too much electronic stuff fail where basic electromechanical most likely would have held.




I would agree that you just wire a wye-delta in delta only to use a soft start. The reason to use one is either because of inrush or excessive torque putting too much mechanical load on the system or a small number of other reasons such as the fact that you can inch with one for adjusting/aligning equipment.

A magnetic starter will last about 25-30 years with almost no maintenance with typical use. Usually the starter coils, aux contacts, or main contacts are the wear parts. A soft start gives out at around 15-25 years usually either SCR worn out or snubber caps are shot, or sometimes control boards. All of this is easily replaceable at about the same costs as magnetic starter repairs. Soft starts are mature technology...virtually unchanged in the past 25-30 years unlike VFDs. Wye-delta and autotransformer starters have a lot more moving parts and fail more often from what I see with them. The big problem with either of those is you get 65-75% of name plate torque maximum so if it’s a centrifugal fan or pump you’re fine but not pretty much everything else that is constant torque. Electronic soft starts fix this so there is really no reason to bother with delta-wye or autotransformer starters.

As to overloads I am not a fan of bimetallic. Their biggest feature is small size. But they cool down too quick and their calibration drifts up or down over time. A eutectic only drifts down as solder evaporated or flings out. Electronic overloads are about twice as reliable, don’t drift (at least the microprocessor ones), are cheaper (AB E3plus excepted), have lower heat loads/losses, handle more conditions, eliminate the need to stock a huge number of heaters and relay sizes, simpler to configure in most cases, are immune to temperature differences and changes, and some help with diagnostics like the SEL 710 for 4160 motors. So I struggle to find a good reason to use eutectic overloads but I will use them every time over a bimetallic.


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## goodtimesgladly

paulengr said:


> The relay will trip so that's not really a problem. If the voltage on the SCR exceeds what is effectively the avalanche point if you think of it as a diode, it self commutates...basically it starts conducting regardless of what the gate is doing or did. The voltage at which this occurs is also reduced if the voltage has a sharp increase (dv/dt). This is why all soft starters have or need both snubbers (little RC or LC circuits clipped to the sides of the rails) and surge arresters (MOV's). What you are doing pretty much bypasses that protection.
> 
> Going with the protection idea though, FUJI and ABB both make some reasonably priced breakers that support a cheap little shunt trip module. This allows you to send a trip command to an external breaker in the event of a fault and shut everything down. I've seen it on several soft starters of this design. But as you said...the cost difference is so miniscule that by the time you spend all this extra money to try to make a goofy delta-wye soft starter, you could just as well buy the bigger soft start and just wire the motor up for full voltage all the time, and buy a 3 or 9 lead motor next time and save the extra cost of the 6 or 12.


Very well stated.
The problem or situation now is that equipment manufactured today is geared toward efficiency. Didn't use to be a problem until energy prices soared. The future is not going to be the old days of DOL starting. DOL is too hard on the equipment and that is unarguable. It is a cheap way and reliable of course to run a motor. The exception is that if the motor has too many starts per hour then soft starter is not considered. This is true not only in the electrical side of manufacturing or processing equipment. Refrigeration compressors for example built today are engineered for optimum efficiency and then coupled with the most efficient motor to drive it makes a great marriage. Dol starting is a cheap way to start a motor but slamming the equipment causes more damage than what you save as opposed to additional cost of a soft starter. I will argue that soft starter will save on demand charges also and if wired with a bypass or internal bypass will not have any heat loss through the SCR's.
Back to the overload subject. The new electronic overload will not only trip faster but will also depending on the model provide data of the motor performance to optimize efficiency. I own a small manufacturing facility and not one 3 phase motor is DOL. All soft start or VFD. I have saved thousands of dollars a year in demand charges and kilowatt hour charges. But that is not the only savings. Reduced wear on the drive systems alone pay for soft start. Like everything else the price will come down on these components and have already. The day will come when VFD and soft starters will out sell conventional motor starters. 
DOL guys please do not condemn me but a DOL start is like starting your car in wide open throttle as opposed to starting in idle. Think about it.


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## paulengr

I’m not anti DOL, far from it. I’m not a VFD for everything guy either. Each has its place. Understanding that makes you more successful. I also know when and where and how to successfully apply IEC contactors as well as vacuum contactors. Each has a place and a right way to do it. Being comfortable with all of them is best, not attempting to fit square pegs in round holes. And by the way DOL is not the cheapest nor the most reliable in all cases nor is any other starting method.


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## goodtimesgladly

paulengr said:


> I’m not anti DOL, far from it. I’m not a VFD for everything guy either. Each has its place. Understanding that makes you more successful. I also know when and where and how to successfully apply IEC contactors as well as vacuum contactors. Each has a place and a right way to do it. Being comfortable with all of them is best, not attempting to fit square pegs in round holes. And by the way DOL is not the cheapest nor the most reliable in all cases nor is any other starting method.
> 
> 
> Sent from my iPhone using Tapatalk


You are Absolutely Correct. I am however for the most part anti DOL. I am also an end user and I own countless motors from fractional HP to 250 Hp and I see what effect they have on my equipment.They do have their place but that place is shrinking. Times they are a changing and "each has a place and a right way to do it"


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## Wax

I have a wye start delta run motor that the customer says they want it hooked up high voltage it is a baldor reliance super e 125hp 460 volt. Should I wire it delta or wye


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## frenchelectrican

Wax said:


> I have a wye start delta run motor that the customer says they want it hooked up high voltage it is a baldor reliance super e 125hp 460 volt. Should I wire it delta or wye


It all depending on the starter and the system set up.

there are few ways to do this. 

but need more info before I can go further on Wye Delta system.

Typically most soft start and DOL ( direct on line or across line starting system ) useally hooked up in delta.

If you have VSD hook it on delta. 

Wye Delta starters they are very specfic on the hook up on it.


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## Wax

It is controlled by an old Mc board


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## Terryp

micromind said:


> This motor will be perfectly happy to be started across the lines or with a soft-start. Just connect it ∆.
> 
> If it's 6 leads, the ∆ connection would be L1 = T1&T6, L2 = T2&T4, L3 = T3&T5.
> 
> Starting a 100HP motor across the lines is somewhat common here especially in a fair-size industrial facility.
> 
> The starting current of a 100HP 575 volt motor will be around 600 amps.


 If you have a low inertia load to start yes you can get by with starting on Delta across the line but a medium to high inertia load the inrush will go very high on you if you have your overloads sized properly they will likely not stay in. Depending on the load or more directly the inrush you are risking burning open the delta windings in the motor especially after repeated starts. I have witnessed failed attempts at across the line starting on the delta windings several times in my career. A soft start properly set up will get you started and it will do it softer than a wye delta starter but both a soft start and a why delta starter will do the job just fine. You can build a wye delta starter with 3 contactors and a timer but with the relatively low cost of soft starters and the rising cost of mechanical contactors many people are electing to use a soft start.


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## Terryp

Terryp said:


> If you have a low inertia load to start yes you can get by with starting on Delta across the line but a medium to high inertia load the inrush will go very high on you if you have your overloads sized properly they will likely not stay in. Depending on the load or more directly the inrush you are risking burning open the delta windings in the motor especially after repeated starts. I have witnessed failed attempts at across the line starting on the delta windings several times in my career. A soft start properly set up will get you started and it will do it softer than a wye delta starter but both a soft start and a why delta starter will do the job just fine. You can build a wye delta starter with 3 contactors and a timer but with the relatively low cost of soft starters and the rising cost of mechanical contactors many people are electing to use a soft start.


Of course you also have the more expensive option of using an AC motor drive but this gives you alot more flexibility such as speed control.


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## just the cowboy

@Terryp Welcome to the forum. Check the dates of posts you reply to. It is a zombie thread as in last reply was almost 3 years ago. 

Cowboy


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