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Hi-Pot & El-Cid

Hi-Pot & El-Cid

Hi-Pot & El-Cid

(OP)
which one to use, when and why?

have a generator off for a scheduled outage and moisture/humidity to high for Hi-Pot.  would El-Cid provide condition in place of Hi-Pot?

RE: Hi-Pot & El-Cid

El-CID is a tool for detecting defects within the stator core. Hi-pot is normally confined to winding testing. Were you proposing to Hi-pot the core, and what were you expecting to achieve?

RE: Hi-Pot & El-Cid

(OP)
a hi pot was scheduled as a "let's take a look at the condition of the windings while the unit is down".

as an alternative to not doing anything i was thinking at least an ElCid might give us info on the core if it can be done under high moisture/humidity conditions.

RE: Hi-Pot & El-Cid

Suggest you talk to one of the specialist generator test contractors - Doble Powertest in the UK, for instance - and get their opinion.

An RSO is another test which you could reasonably carry out, although when you ask about El-CID in high humidity, you may as well ask 'em about an RSO too.

Out of interest, where are you?

RE: Hi-Pot & El-Cid

(OP)
thanks for the info.  the rotor is not being removed so testing is limited at this time.  bus couplers were recommended for online monitoring but no decision has been made.

i am currently working for a client in the US that has plants accross the country.

RE: Hi-Pot & El-Cid

Suggestion: Visit
http://www.vpuc.com/minutes/r102300.htm
for:
 The additional test (EI CID) is to verify the condition of the insulating material on the stator (unit was installed in 1954).  

RE: Hi-Pot & El-Cid

(OP)
thanks for the info.  someone figured while to TG was down they would do something.  the main concern was WHAT, if any, testing could be done under hi moisture/humidity conditions.

there was no other concern for generator problems and none existed before it came down for the scheduled turbine outage.

RE: Hi-Pot & El-Cid

Usually a Power Factor or Insulation Resistance Test would be recommended.  I personnelly wouldn't do a High Potential Test even with low humidity.  Maybe even a fancy Partial Discharge Test.

EL-CID test would not tell you anything about the insulation only tells you if you have a core problem.

RE: Hi-Pot & El-Cid

Measure the PI (10 min IR/1 min IR), to check the winding dryness before any Hipot/Surge test/Partial discharge test. A humid atmosphere doesn't necessarily mean a winding with moisture.

ELCID test checks the core only.

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