Generator field

[halms]

Has anybody ever heard of a Hydrogen cooled generator being damage due to a shorted field coil?

 

[DanDel]

Are you suggesting that a shorted field coil isn't a problem with a hydrogen cooled generator?

 

[jbartos]

Suggestion: The field protection relay may malfunction or be improperly set. Check with hydrogen generator manufacturers and service firms.

 

[DougMSOE]

If you mean can a shorted field coil cause an explosion in a hydrogen cooled generator, NO! The air to H2 ratio is 99.9% H2, out of the explosive atmosphere range. If the H2 purity meter is operational this explosive atmosphere range would never be approached.

 

[DougMSOE]

PS
The field protection relay is to detect field ground problems, not shorted turns.
Shorted turns occurr all the time. I have 5 turns shorted as we speak in one of my units. Repair is 16 months away and the unit has been operating for about 3 years this way.

 

[chicopee]

To DougMSOE-You stated that the ratio of air to H2 is 99.9% H2. Should it not be the reverse ie H2 to air ratio?

 

[busbar]

chicopee — 0.1% hydrogen would not qualify the generator as hydrogen cooled.

 

[jbartos]

Suggestion: The shorted field coil may also be shorted over the ground. See details and potential protections:

http://www.gepower.com/publications/en_us/pdf/GER4212.pdf

 

[DougMSOE]

chicopee, H2 cooled generators have almost total H2 in the generator. What small % of air is usually from the in-leakage around the bearings.
I guess I was not clear on this.

 

[Shortstub]

halms,
What was the extent of the damage? Was an explosion one of the manifestations?