generators in parallel ques?

[wireman1]

two generators 2000 amps are going to be wired in parallel to feed a 4000 amp service rated distripution panel,with a service rated transfer switch and solid neutral connection.is the grounding for this system different or do you just tie all grounds and neutrals together at one point at the distribution board where the ats switch is. is a diagram available for this type of connection thanks for any help

 

[iceworm]

thanks for any help

I don't have any help - just a bunch of questions. This is a non-trivial installation. Most solutions will be inter-related design based decisions. Possibly (probably) way beyond DIY engineering by MH Forum

two generators 2000 amps are going to be wired in parallel to feed a 4000 amp service rated distripution panel,with a service rated transfer switch and solid neutral connection.
Just curious: Is this 13.8kv, 480V, solid grounded, impedance grounded, 208V?

Is the grounding for this system different
Different than what?

or do you just tie all grounds and neutrals together at one point at the distribution board where the ats switch is.
Rarely does one see ALL tied together at one point - but possible

is a diagram available for this type of connection
This is not a cookie cutter install. Have you spoken to the engineer of record? I suspect there are stamped engineering prints for this.

ice

 

[lakee911]

do you just tie all grounds and neutrals together at one point at the distribution board where the ats switch is.

Without switching the neutral, that is generally the practice. Lots of other thing to be considered that I'm not aware of though. As Ice said, check w/ the design engineer. He's the only one at this time privy to all of the specifics for your install.

 

[tom baker]

Possibly (probably) way beyond DIY engineering by MH Forum

What do you mean DIY engineering? All of us take a lot of pride in our knowledge. There are many electrical engineers that post here.

 

[GoldDigger]

What do you mean DIY engineering? All of us take a lot of pride in our knowledge. There are many electrical engineers that post here.

I think a more accurate statement would have referred to long distance internet engineering versus feet-on-the-ground engineering with access to all relevant information.

 

[iceworm]

I think a more accurate statement would have referred to long distance internet engineering versus feet-on-the-ground engineering with access to all relevant information.

Thank you
That's a lot better than I could have said

ice

 

[Duncan8943]

Definitely do not just hook them together

Definitely do not just hook them together

I don't believe that hooking the generator outputs will be the solution. You would have two sine wave voltage sources--there would need to be extra equipment to get the sine waves aligned.

 

[iceworm]

two generators 2000 amps are going to be wired in parallel to feed a 4000 amp service rated distripution panel,with a service rated transfer switch and solid neutral connection.is the grounding for this system different or do you just tie all grounds and neutrals together at one point at the distribution board where the ats switch is. is a diagram available for this type of connection thanks for any help

Two issues came to mind that affect solidly grounded parallel generation.

Equipment damage in the event of a fault:
Generators are build to withstand the winding stresses developed from a fault - provided the CBs trip in time (coordination takes into account the gen damage curve). But sometimes the fault occurs inside the gen (shaking windings rub a hole in the winding insulation). Now the issue is to get the gen shutdown before the stator iron is destroyed - so you still have a rewindable gen, and not just scrap iron.

With parallel generation, the issue is the other generators can sometimes deliver more fault current than the faulted gen can stand. In these cases, it is a good design practice to insert an impedance in the Neutral Common Point to Ground connection.

Maintenance on solidly connected neutral, parallel generation:
If one generator is taken out-of-service for repair, the windings are still connected through the nuetral connection. If there is a fault out on the system, the neutral can be elevated for a short period until the CBs trip. And if the tech has their hands in the middle of the winding connections - not good. If the tech lives through it - they are usually really irritated.:rant:

Recommend installing a maintenance disconnect switch in each gen neutral. As part of the isolation for maintenance, lock this switch off. Just use a standard two or three pole disconnect. If fused - slug the slot. If there is concern the switch could be left open, use one of the other poles in the gen start/run circuit.

I don't know where to suggest looking for diagrams. Maybe some of the IEEE color book series for a start.

Personally I have never liked solidly grounded generation in the 13.8kV, 4160V, or 480V range - especially if paralleled.

ice