How to remove the power transformer thermal trip function?

[Beengineer]

DO you disconnect at the end of Hot Spot Winding temmperature gauge, or at the relay end?

Is the transformer outage required?

Thanks

 

[ScottyUK]

I'd try to ensure that the minimum amount of live cable is left, so I'd disconnect at the relay end. If you need to ask this kind of question should you be messing about with a transformer protection system? Why do you want to disable the gauge? Hiding the problem is different to fixing it.


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If we learn from our mistakes I'm getting a great education!

 

[Beengineer]

Hi Scott,

The trips were always caused by wrong setting or the mel-function of the old mechanical gauges. So we decide to remove the automatice thermal trip function, replace with manual trip. Normally, industry wide, the thermal trip is set at 140C, but we were seldom to load the transfomrer up to 90C. So there will be plenty time for the dispatcher to react after alarms set out. It's quite common to remove the thermal trip function

 

[Beengineer]

Is there a switch inside the mechanical gauge that can turn the thermal trip "off"?

 

[oldfieldguy]

Take care mucking about with winding temperature gauges. Remember that typical ones use a current transformer to obtain an analog of the effective heating current, and we all KNOW about open-circuiting CT's.

Of course, if all you're doing is lifting the leads from the contact, then there's no problem, but some people get ambitious.

old field guy