I need a high speed form A contact (Normally Open commanded closed) be used to drop out a solenoid valve. The form C contact is much slower and millisec's count in the application.
The valve is 125 VDC requires a 180 milliamps to be be held in. Pull-in Voltage: 95-70 vdc & Drop-out 50 to 20...
Is there a Code or Standard that allows motors that move air across itself to be overloaded more than the service factor? An example is a fin/fan motor that is rated at 3.2 amps full load (575Vac)operating at 3.8amps. This is an ~19% increase.
Thanks in advance for your comments/references.
I am looking for the testing intervals for protective relays? Every two years seems to be a rule of thumb but many standards reference the manufacuture's manuals for recommended testing time frame. The manufactures in many cases say testing is not required after the initial setup, calibration...
What different software tools are being used to documenting protective relay settings. Such as plotting R-X(pu)& P - Q diagrams, decrement curves, generator capability curves, vector diagrams and/or symmetrical components?
Does any one have excel files that can accomplish these tasks? Or...
Does anyone have list of world wide generator manufacuturers in the 45 to 120MVA size ranges? A web link? It would be very much appreciated. Google does get it. Thank you.
Has anyone used the Learning CD from the GE Multilin web site? The CD is titled FUNDAMENTALS OF MODERN PROTECTIVE RELAYS. There is a demo on the web site.
Is there someone has used it and has an opinion? Did you get it for a less than $1200 a copy?
Thank you.
I have a question about a gas turbine project I'm working on. The turbine has liquid #2 FO that is heated to 155 deg F and circulated continuously for emergency standby. This fuel is contained in the piping and heater system and does the area surrounding the piping need to be explosion proof...
Is insurance personal insurance required if you stamp engineering drawings for a large corporation? I transferred to a different division of a large company were stamping the drawings is expected of me by the engineering manager (who is not a PE). The manager says personal insurance is not...
Is there a good reference/web site that has the requirements for working clearances in front of low voltage motor control centers and distribution equipment? I am in the US designing for a project in Holland with very limited space. Thank you.
Does anyone have the conversions for IP proectection classes compared to the NEMA ratings? I am doing some work in europe and need to located a good reference equatings the two standards as close as possible.
What is the effect of having a class F rotor installed in a class b generator stator? There is two generators both 50MW at 13.8KV 60Hz. One has a bad stator and one has a bad field rotor. Can they be combined to make one good generator? What would the final insulation level be?
If someone...
I need some help finding the standard BIL levels for synchronous generators. Does any one have a link or reference?
The application I am designing has a 50kV BIL (4.5MW) and the Utility is stating this is not hign enough for connection to their system, so they are requesting an isolation...
Can an existing 13.8 KV GE magna-blast 500MVA rated switchgear be retrofitted with current limiting fuses on the supply side to protect the switchgear due too changes on the utility side and with the addition of on site generation?
The SC calculations are just above the 500MVA. Fuses would...
I am working on a electrical chiller replacement job. It involves replacing an constant speed chiller with a VFD chiller. I planned on using the existing CB to feed a new harmonic filter physically inplace of the old motor starter(adjacent to existing powerpanel) and then connecting the filter...
Is there a tester available (similar to foot candles tester) to tell if a flourescent lamp is on a magnetic or electronic ballast? If you would let me know who manufactures this type of device and a website address it would be a real help.
Thank you for your assistance.
I have an array of 8760 hourly data kW readings for a year (24 by 365). I want to count the number of hours >= 15000 this works but then using and the AND logical it does not work. Here is formula that does not work =countif(D4:AA368), (AND>14900, (D4:AA368)<=15000)) it gives me zero.
Can...
Has anyone had any experience with applying an autotransformer for a step-down application 460 V 60hz to 220 V three phase 1000 kVA?
The kVA required will be decreased by 48%. I now typically you would like to see a closer voltage ratio for an autotran. application.
Does anyone have a good...
I have a dual voltage Howell International Inc Plainfield,NJ. The motor is wired for 220 volts. The part no. 38J1151001 69B265. 3/4 HP 1725 RPM. It is used in a machine tool application.
It appears Howell is out of business.
Does any one know how to wire it?
Thanks.
