standby generator boding(2 or 3 pole transfer switch)

[kohler_guy]

i have been in this businees for 5 yrs and and 10 years including the whole elctrical side... i no what the code says about bonding the neutral and ground at the generator when not using a switched netral.however... i do not agree with this, and here is why- what happens when utility looses their neutral and u have floating neutral, now since ur ground and neutral isnt bonded at the gen, u will now have the same problem when it goes to gen power since utility is NOT bonded. does anyone agree with me? ever seen this happen?

 

[roger]

what happens when utility looses their neutral and u have floating neutral, now since ur ground and neutral isnt bonded at the gen, u will now have the same problem when it goes to gen power since utility is NOT bonded. does anyone agree with me? ever seen this happen?

No, (or should I say know :roll when you transfer to generator power you will not have an open neutral, bonding to the GES has nothing to do with this.

BTW, IMO you should try to leave texting shortcuts out of your posts.

Welcome to the forum

Roger

 

[ceb58]

i have been in this businees for 5 yrs and and 10 years including the whole elctrical side... i no what the code says about bonding the neutral and ground at the generator when not using a switched netral.however... i do not agree with this, and here is why- what happens when utility looses their neutral and u have floating neutral, now since ur ground and neutral isnt bonded at the gen, u will now have the same problem when it goes to gen power since utility is NOT bonded. does anyone agree with me? ever seen this happen?

Deja Vu, Roger and I had this conversation last night. No I do not agree. Reason being if you are on gen. power the gen. could care less about the utility neutral. The return current wants to go back to the source,being the gen. The simple way to look at the whole system in a non separately derived system is to pretend every thing past the main service disconnect is a sub panel. the gen is a sub, the transfer switch is a sub. The same rules apply that the neutral and EGC are only bonded in the first disconnecting means. After that every thing is separated to prevent unwanted currant on metal parts.

 

[roger]

Good evening Curtis, we did infact have this convesation last night.

Do you and Wanda want to meet us at the Mexican Restaurant tomorrow night before you go home?

Roger

 

[ceb58]

Good evening Curtis, we did infact have this convesation last night.

Do you and Wanda want to meet us at the Mexican Restaurant tomorrow night before you go home?

Roger

Love to. I will give you a ring on the celleiphone

 

[kohler_guy]

i got to tell you, have seen this happen many times, utility looses a neutral, the gen starts b/c of voltage problems, 3 pole switch transfers then more stuff gets burned up b/c u have floating neutralon the gen, noone has seen this happen?

 

[roger]

i got to tell you, have seen this happen many times, utility looses a neutral, the gen starts b/c of voltage problems, 3 pole switch transfers then more stuff gets burned up b/c u have floating neutralon the gen, noone has seen this happen?

Look at the illustration below, the loads are being served from the generator, the red arrows represent the nuetral current from the loads.

Please explain how the open neutral on the utility side of the switch will have an effect on the current returning to the generator.

There must have been some other improper wiring or a generator output fault to cause things to burn up.

Roger

 

[ceb58]

i got to tell you, have seen this happen many times, utility looses a neutral, the gen starts b/c of voltage problems, 3 pole switch transfers then more stuff gets burned up b/c u have floating neutralon the gen, noone has seen this happen?

I have to agree with Roger and his diagram. One has nothing to do with the other. But you are saying a 3 pole switch. You are talking 3ph aren't you? If you see burned up equipment because of dropping a neutral on the utility side then that is where the problem came from not the gen. if every thing is wired correctly. Still if you are talking 3ph I have seen some of the Kohler ATS that were 3ph but it only monitored 2 legs of the system. And I have seen the situation where the utility dropped 1 leg and it happened to be the leg the ATS was not monitoring. It caused problems with single phasing some motors but that was not the gen. fault just a poor design for phase monitoring in the ATS.