3 phase, 3 wire ATS

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mbrooke

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kwired said:
Too general of a question, maybe one has a three phase three wire delta supply - no neutral to monitor even if you wanted to:happyyes:
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Yes, 3 phases and a ground but no neutral. Single phase 120/208 is via a delta primary transformer.
 
steve66

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Well, the ASCO 7000 ATS's will work on 3 wire systems.

From a set of shop drawings I have, it lists Voltage 3 Phase (3 or 4 wire), and then it lists all the available voltages.

This one just happens to be going on a 3 phase Wye system, with no neutral ran to the ATS or MCC.

But is the ATS going on the primary side of this transformer? If not, and its going on the 120/208V system, you should have a neutral.
 
ATSman

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ATS Voltage Sensing

ATS Voltage Sensing

mbrooke said:
Do all ATSs sense the neutral lug (phase to neutral monitoring)?
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My experience with all ATS manufacturers: the answer is no. I can not think of one brand that senses phase to neutral voltage.
What would be the reason? Whether it is a 3-wire Delta or 4-wire Wye monitoring the 3 phase to phase voltages will indicate whether the source is good or not for transfer of the load. Your typical ATS always senses the 3-phases on the utility source. This is because of the danger of single phasing from the utility causing damage to the load. The sensing on the emergency source varies between 3-phase and single phase depending on the age and manufacturer of the unit. Most newer microprocessor controllers (GE-Zenith MX-150, MX-250, MX350) give you the option of selecting 3-phase or 1-phase voltage sensing for the emer source.
 
mbrooke

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steve66 said:
Well, the ASCO 7000 ATS's will work on 3 wire systems.

From a set of shop drawings I have, it lists Voltage 3 Phase (3 or 4 wire), and then it lists all the available voltages.

This one just happens to be going on a 3 phase Wye system, with no neutral ran to the ATS or MCC.

But is the ATS going on the primary side of this transformer? If not, and its going on the 120/208V system, you should have a neutral.
Click to expand...


The ATS is on the primary side. All the loads are connected phase to phase (mostly delta primary lighting transformers and a few 3 phase motors), no neutral is present. Only the 120/208 portion has single phase loads but that's after the ATS and transformer.

My question is, how does one spec for a 3 wire only ATS, if some makers even offer it? All the ATS specs for Kohler and Asco seem to show a connection from the neutral lug to the controller as well as having phase to neutral loss of voltage adjustments in the programming but no talk of disabling it.
 
mbrooke

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ATSman said:
My experience with all ATS manufacturers: the answer is no. I can not think of one brand that senses phase to neutral voltage.
What would be the reason? Whether it is a 3-wire Delta or 4-wire Wye monitoring the 3 phase to phase voltages will indicate whether the source is good or not for transfer of the load. Your typical ATS always senses the 3-phases on the utility source. This is because of the danger of single phasing from the utility causing damage to the load. The sensing on the emergency source varies between 3-phase and single phase depending on the age and manufacturer of the unit. Most newer microprocessor controllers (GE-Zenith MX-150, MX-250, MX350) give you the option of selecting 3-phase or 1-phase voltage sensing for the emer source.
Click to expand...


The Kohler schematics show wiring from the neutral lug/buss over to the electronic control. I have seen the actual ATS in person and I can confirm this.

http://www.kohlerpower.com/onlinecatalog/pdf/gm46266.pdf

As well as the spec sheets say under LCD display "line to neutral voltage" (page two)
http://www.kohlerpower.com/onlinecatalog/pdf/g11108.pdf


Not saying your wrong but its confusing me:dunce:
 
ATSman

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mbrooke said:
The Kohler schematics show wiring from the neutral lug/buss over to the electronic control. I have seen the actual ATS in person and I can confirm this.

http://www.kohlerpower.com/onlinecatalog/pdf/gm46266.pdf

As well as the spec sheets say under LCD display "line to neutral voltage" (page two)
http://www.kohlerpower.com/onlinecatalog/pdf/g11108.pdf


Not saying your wrong but its confusing me:dunce:
Click to expand...
Ok, I see what your question is now and you have a valid point. I noticed this on some ASCO dwgs I have.
You are asking what do you connect to the P1-22 and P1-23 inputs on the PSB? I need some time to look into this but it would seem to me that there would be programming settings in the Setup menu where you would choose the type of system you are installing the ATS on; 3-wire Delta or 4-wire Wye. If you choose Delta then the phase to neutral voltage setting you now see will disappear and you would not connect anything to terms P1-22 or P1-13. It would be much the same way as when you are installing power meters or protective relays for the first time. I would check the Setup menu after you power up the controller. It is set for 4-wire and you need to change it to 3-wire (Delta) to solve your problem. You will not do any damage by not connecting any wires to those terminals, it just your readings will not be correct until you make that change to Delta.
We need the controller programming manual for this information.
 
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mbrooke

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ATSman said:
Ok, I see what your question is now and you have a valid point. I noticed this on some ASCO dwgs I have.
You are asking what do you connect to the P1-22 and P1-23 inputs on the PSB? I need some time to look into this but it would seem to me that there would be programming settings in the Setup menu where you would choose the type of system you are installing the ATS on; 3-wire Delta or 4-wire Wye. If you choose Delta then the phase to neutral voltage setting you now see will disappear and you would not connect anything to terms P1-22 or P1-13. It would be much the same way as when you are installing power meters or protective relays for the first time. I would check the Setup menu after you power up the controller. It is set for 4-wire and you need to change it to 3-wire (Delta) to solve your problem. You will not do any damage by not connecting any wires to those terminals, it just your readings will not be correct until you make that change to Delta.
We need the controller programming manual for this information.
Click to expand...

Yup! You got it!:D I don't have the manual for programing, but its those connections from the neutral buss to the control PSB that throw me off. In my mind (Im guessing) the control has a need for a neutral, either for electronic power, sensing or both. I never stopped to think about it until now when I realized the ATS had this connection. I went looking through the Kohler and ASCO specs and could find anything in the ordering info asking for "4 wire" or "3 wire". Only solid and switched neutral, thinking solid neutral was just a buss kit with no connection to the electronic control.

Your explanation does make sense if that's the case. Any way to find out?
 
ATSman

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mbrooke said:
Yup! You got it!:D I don't have the manual for programing, but its those connections from the neutral buss to the control PSB that throw me off. In my mind (Im guessing) the control has a need for a neutral, either for electronic power, sensing or both. I never stopped to think about it until now when I realized the ATS had this connection. I went looking through the Kohler and ASCO specs and could find anything in the ordering info asking for "4 wire" or "3 wire". Only solid and switched neutral, thinking solid neutral was just a buss kit with no connection to the electronic control.

Your explanation does make sense if that's the case. Any way to find out?
Click to expand...

See my post #10.
 
ATSman

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jrannis said:
I have installed many of these and I can tell you for a fact that the neutrals are normally connected separately and not monitored for amperage.
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Amperage has nothing to do with voltage sensing on ATS source voltages.
Please read the posts and educate yourself before you rattle off jibberish.
 
mbrooke

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ATSman said:
See my post #10.
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OK, thanks! :)I have to admit your right, I looked at ASCOs spec sheets for ordering and one can actually order an ATS without any neutral buss or lugs along with a "3 wire option" Guess Kohler just likes to be different:cool:
 
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