DCNew site to be designed.
Measured 10 to 20 amps dc ground current at site.(Source of DC current will never go away and is generated by some other group).
What is the best way to protect the rebar in the concrete from electrolysis?
Epoxy coatings?
Galvanizing?
Sacrificial anodes?
Thanks
New site to be designed.
Measured 10 to 20 amps dc ground current at site.(Source of DC current will never go away and is generated by some other group).
What is the best way to protect the rebar in the concrete from electrolysis?
Epoxy coatings?
Galvanizing?
Sacrificial anodes?
Thanks
A large free standing 400 amp Cutler Hammer/Westinghouse disconnect switch violently vibrates when the SCR controlled lighting it feeds for a movie set is turned on.
The noise is so loud they have had to stop filming.
Are there any quick low cost solutions to this problem?
Thanks for any help.
2 mva. transformer at 10 % max load recently failed (tertiary delta winding connection opened).
After removing the coils from the core,a partial bluish colour was noticed on the core leg vertical steel plate on each side of this leg.
Question:What could cause this discoloration at such low...
2 MVA Dry Type Tx.
27.6 kv./480 v. wye/wye
2 years old -30% loaded
Note:The transformer manufacturer completed the delta by using a #6 jumper wire instead of the interconnecting busbar they had used for the rest of this delta tertiary.
The wire melted and caused a phase to phase flashover.
We...
The utility is being plagued with their L.V.wires(less then 600 volts) in connection boxes corroding off and then making electrical contact with their sidewalk metal cover plates,metal lighting poles,streetwalk signs and metal push button controls .Their fix it solution is to install a 1:1...
We have approx. 20-30 amps of AC 60 Hz. current flow on the entire copper waterpiping system in a large brand new 400 unit condo project.The water is from wells in the area.The water only in these condo units smells like rotten eggs,has a blue tinge to it and sometimes sediment flows out of the...
We recently turned back on an indoor 27.6 kv. SF6 breaker feeding a transformer with no connected secondary load.At the instant this breaker closed(connected on the same 27.6 kv.bus) an indoor nearby 27.6 kv. loaded dry type transformer flashed over ( high voltage winding terminal to ground)...
Because of building wiring errors,30-40 amps of AC neutral/ground current was flowing on these water pipes in a large commercial building(water source is wells and is very hard).
Is it possible for a copper chemical electrolysis reaction to occur and create large constant green deposits to be...
3-1200 KW. diesel generators are started up and paralleled together thru a Woodward electronic package.
The entire stator winding assembly in 1 geny all of a suddenly becomes loose and mechanically rotates by approx. 10 degrees.
Question:
Before any breakers have a chance to trip,would you...
At our site,a contractor accidentally tripped(while x-raying the floor above) our CO2 systems for our back-up generators(not running at the time of the trip) that are in a totally enclosed soundproof enclosure within our building.Once the CO2 is replaced,can these generators be immediately...
At approx. 4 pm everyday the phase to ground voltage jumps up from 347 to 1200 volts on 1 phase of a 600 volt delta system in a plant.
15-20 hours later the voltage drops back to 347 volts phase to ground.
Several large motors and circuit boards have alrerady been damaged.
Will be at site...
These (non-fused) 1.67 volt cells can each produce 14,000 amps on short circuit.
There are over 1000 battery cells in this room that require regular mtce.
What P.P.E. (arc flash)clothing would you recommend.The current standards seem to have missed this area.
The customer has a 10 MW. generator(4160 volt) wye connected to a wye-wye (27.6 kv.) step-up tx.There is no neutral wiring between generator and tx.The wyes at the tx. are solidly grounded and the wye at the generator is grounded thru a .4 ohm reactor.
There is no power to the high side of the...
I have received from SKM additional breaker info to be inserted into the program's general breaker library.
The insert instructions they sent are for their large multi bus program (it will not work on this smaller bus program).They don't seem have breaker library insert instructions for this...
Went to a major international airport yesterday.
When the passenger planes roll up to the gate and stops,temporary airport power is plugged into the plane.
Power is 200 volts 3 phase 4 wire 400 hz.
A new series of airplanes when plugged in to this power source ,electronically refuse to turn...
I have posted all the info in another chat forum.(here is the link)
http://forums.mikeholt.com/showthread.php?t=88114
Note:This is an ongoing engineering investigation and new field info will be posted as it is received.
I thought you might be interested in adding your comments.
Interesting picture-car high voltage theft protection system (may 2007 magazine)
More tests and high voltage experiments at:
http://tesladownunder.com/
Enjoy
