I have 9 Doosan portable generators, that I am needing to remap from a wye to a delta, (if it is possible) at least a 240/120 with a stinger. Looking over the VSS diagram it looks like a can give myself the 240 with a stinger but if I'm looking at it right it may disrupt my 480/277 VAC on B ph of my VSS. If I can just re tap the unit to a delta and just run with the two selections would be fine. Any ideas?????
trying to remap a wye into a delta
- Thread starter yogi32536
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zbang
Senior Member
- Location
- Roughly 5346 miles from Earls Court
Knowing which model you're working on would help. You have the manual already? (I found one at https://csdieselgenerators.com/Imag...290-G450-operation-and-maintenance-manual.PDF, but as manuals go, it's not great. Look around pages 44-50.)
Usually, the windings are always wye connected so if you want 240v delta, you select "low voltage" 208/120v and turn up the voltage regulator to get 240 between hot leads (and 139 H-N, which is unused). Very few gensets will produce 240/120 3-ph 4-wire (aka "high-leg delta").
Usually, the windings are always wye connected so if you want 240v delta, you select "low voltage" 208/120v and turn up the voltage regulator to get 240 between hot leads (and 139 H-N, which is unused). Very few gensets will produce 240/120 3-ph 4-wire (aka "high-leg delta").
Adjusting it up to the 240/139 is the issue, it is tripping the UPS breakers in our SCADA systems. I have blue stars that are in the high leg delta, I was just seeing if I could remove the zig zag on the single do away with the 208/120, and just have the 480/277, & the 240/120 with a stinger, I have the manual with the vss switch positions and the wye diagram
Birken Vogt
Senior Member
- Location
- Grass Valley, Ca
Voltage Selector Switch? Some of your jargon is not clear to me. Also what is a blue star? Is it requiring the high leg to be actually high?
You can certainly reconnect the genset for 120/240 high let, but you will not find any way to make the other positions of the rotary switch work any more. I would bypass/remove the rotary switch if forced to do this.
It sounds like you want it to be selectable between 120/240 delta and 277/480 wye which just isn't going to happen.
What about adjusting it to 220/127 like Mexico uses or 216/125? Split the difference. It's worked for me.
You can certainly reconnect the genset for 120/240 high let, but you will not find any way to make the other positions of the rotary switch work any more. I would bypass/remove the rotary switch if forced to do this.
It sounds like you want it to be selectable between 120/240 delta and 277/480 wye which just isn't going to happen.
What about adjusting it to 220/127 like Mexico uses or 216/125? Split the difference. It's worked for me.
Joethemechanic
Senior Member
- Location
- Hazleton Pa
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- Electro-Mechanical Technician. Industrial machinery
I'm a bit confused about the voltages needed. But with a 12 lead machine you should be able to get whatever you want as long as you can stay at or below the maximum field current.
Although I did a high leg delta on a really old Kohler about 30 years ago and the 120v seemed to be a bit unstable. I never got a chance to figure out why, It wasn't really critical. I kind of suspected it was impedance related
Although I did a high leg delta on a really old Kohler about 30 years ago and the 120v seemed to be a bit unstable. I never got a chance to figure out why, It wasn't really critical. I kind of suspected it was impedance related
VSS: voltage selector sw. Blue star is a brand of generator, to which I have a couple that produce 4 selections 480/277 , 208/120 , 240/120 3ph , & 240/120 single. Which I believe those units are tapped in a delta wye configuration (please correct me if I'm incorrect in that). That is essentially what I would like to know if I can turn the Doosans into. I was thinking it would be possible because it is a 12 lead. If anything just get the 480/277 / 240/120, but also trying to wrap my head around keeping it all on the same selector sw. I can not split the difference of voltage due to the lift stations that they will be backing up would not run on 220VAC. We have mulled around the idea of just bypassing the selector sw. and just put in a separate breaker for the lower voltage, leaving the switch only 480/277.
winnie
Senior Member
- Location
- Springfield, MA, USA
- Occupation
- Electric motor research
A 12 lead alternator has 6 coils, 2 for each phase. You can wire individual phases in series or parallel, to get 120, 139, 240, or 277V across each phase.
You can connect the phases in wye or delta, or 'double delta' for single phase applications.
But the bottom line is you start with 12 terminals and need to connect them together in different ways to get to 4 output terminals. The alternators in your generators can handle your desired output.
The VSS is switching between connections, rather than having to get the wrench out and move jumpers around. The VSS in the Doosan generators may not be capable of switching between your two desired configurations.
Could you draw a schematic of the current switch arrangement and what you are trying to achieve? It sounds like the Blue Star' units have a more flexible VSS that handles more connections.
The simplest approach may be as suggested in post #4, simply remove the VSS and use jumpers.
Jon
You can connect the phases in wye or delta, or 'double delta' for single phase applications.
But the bottom line is you start with 12 terminals and need to connect them together in different ways to get to 4 output terminals. The alternators in your generators can handle your desired output.
The VSS is switching between connections, rather than having to get the wrench out and move jumpers around. The VSS in the Doosan generators may not be capable of switching between your two desired configurations.
Could you draw a schematic of the current switch arrangement and what you are trying to achieve? It sounds like the Blue Star' units have a more flexible VSS that handles more connections.
The simplest approach may be as suggested in post #4, simply remove the VSS and use jumpers.
Jon
Here are the current diagrams that I am working with, one I have scratched on with what my thoughts are on adding and removing jumpers. I just think that because the T2 is the only 480 leg that is tapped into the switch, that in jumping onto the T2, I'm not sure what voltage I will get L-L or on L-N on B at the connection lug in the 480/277 position.
Birken Vogt
Senior Member
- Location
- Grass Valley, Ca
So yes, it appears the request is to have 240 delta or 480 wye. Understandable. And I do know Blue Star generators, just did not make the connection in the beginning.
I have not seen a unit that would do 240 delta on a VSS along with the more common single phase, 208, 480 options usually found.
That has to be a very complicated selector switch. Because 208, 240 single phase dogleg, and 480 are very similar in that only a few connection points need to be moved, 240 delta moves a whole lot more connection points around.
Besides moving the actual load wires around, you will also need to move the voltage regulator, metering, and generator controller taps to their correct places, as well as ensure any Current Transformers still have the right current running through them.
If I had this project, I would study and understand the Blue Star VSS arrangement, including any ancillary AVR/controller taps, and duplicate it that way.
The VSS used is likely to be much longer than the wye connected VSS because it will require more contacts/wires to move. This part may be difficult to source.
I have not seen a unit that would do 240 delta on a VSS along with the more common single phase, 208, 480 options usually found.
That has to be a very complicated selector switch. Because 208, 240 single phase dogleg, and 480 are very similar in that only a few connection points need to be moved, 240 delta moves a whole lot more connection points around.
Besides moving the actual load wires around, you will also need to move the voltage regulator, metering, and generator controller taps to their correct places, as well as ensure any Current Transformers still have the right current running through them.
If I had this project, I would study and understand the Blue Star VSS arrangement, including any ancillary AVR/controller taps, and duplicate it that way.
The VSS used is likely to be much longer than the wye connected VSS because it will require more contacts/wires to move. This part may be difficult to source.
I was questioning the CT's and the voltage metering as well. In conjunction with how the controller is going to read the new arrangement. I am not wanting to get into rewiring the entire unit if at all possible, ie.. sensing wires and more, but I am looking at the blue star's set up to get some clarity, as well as attempting to source a different VSS that would give me the contacts that I need. It may just come down to me telling our SCADA dept. that the 240/139VAC is what they are going to get and to get bigger UPS's. I have approached them once with that, but they are complaining about the cost of redoing their system. So I have been tasked with trying to re configure the units. 5 100kw doosans, and 3 150kw doosans. Once I move on to the 150's I will be back at the drawing board due to the "can" being a Leroy Sumers and the 125's being Motor Morelli's.
winnie
Senior Member
- Location
- Springfield, MA, USA
- Occupation
- Electric motor research
The diagrams show the VSS in positions D or A or G. Are there any other positions available?
-Jon
zbang
Senior Member
- Location
- Roughly 5346 miles from Earls Court
Y'know, it would still be really useful to tell us exactly which model(s) you have. (And, have you tried asking Doosan?)
Joethemechanic
Senior Member
- Location
- Hazleton Pa
- Occupation
- Electro-Mechanical Technician. Industrial machinery
How many kw are these units?
Just those 3 are available
Joethemechanic
Senior Member
- Location
- Hazleton Pa
- Occupation
- Electro-Mechanical Technician. Industrial machinery
I'm guessing you are talking about wastewater lift stations. What are the UPS for? Are the pumps on contactors or VFDs?
winnie
Senior Member
- Location
- Springfield, MA, USA
- Occupation
- Electric motor research
Okay, I don't have time to delve deeply.
Your goal is to get a 240/120 'high leg' delta. With a 12 lead generator connection you want the connection on the bottom left of the first page here:
(They use the same terminal numbering scheme. You want what is shown or anything rotationally similar, eg. N to any of the mid points)
The drawing that you sent with your suggested modification suggests that in your new connection you want to connect T12-T6 and T2-T8, which is not consistent with the desired 240V delta; rather those connections are what you see for paralleling the two coils of each phase to get lower voltage (208/120V wye or 120V L-L delta) Before you go further, you first need to confirm that the desired 240V high leg delta connection you want to use is correct.
-Jon
Your goal is to get a 240/120 'high leg' delta. With a 12 lead generator connection you want the connection on the bottom left of the first page here:
(They use the same terminal numbering scheme. You want what is shown or anything rotationally similar, eg. N to any of the mid points)
The drawing that you sent with your suggested modification suggests that in your new connection you want to connect T12-T6 and T2-T8, which is not consistent with the desired 240V delta; rather those connections are what you see for paralleling the two coils of each phase to get lower voltage (208/120V wye or 120V L-L delta) Before you go further, you first need to confirm that the desired 240V high leg delta connection you want to use is correct.
-Jon
hillbilly1
Senior Member
- Location
- North Georgia mountains
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- Owner/electrical contractor
Yeah, Kohler’s are pretty easy to change, Genercrap’s on the other hand tend to cheap out, and don’t have the multiple windings available. Had to laugh yesterday, a customer I quoted a Kohler for a retail store two years ago, they went with Generac, power was out from the substation, and they were too. The installer was out trying to get it to work, employees and customers lined up outside the doors!
winnie
Senior Member
- Location
- Springfield, MA, USA
- Occupation
- Electric motor research
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