Try "EDR" Im not so sure of the web page, but you can search in at google. The other way is to get the faulth current from your utility or the size ot transformer the supply your 34.5kV distribution from there use unclebob formula...
Guys,
I've read about 50Hz running on 60Hz system and vice versa. We have a centrifuge machine coupled with a motor 415V, 3P 50Hz @ 1500RPM. Our system is 480V 60Hz, and we are planning to put up a step-down transformer at the motor in-feed to level the voltage at 415V. I've read that the...
peebee,
Yes! the 10MVA transformer is grounded at secondary, It is a 13.8kV system 4wire wye, but during the operation of our genset which is a 480V 3P wye generators we connect to the system passing through a Step-up transformer 480v/13800v wye-delta. Which means that during emergency power...
Hi Guys,
Our receiving power is 69kV from our Utilty w/c passes thru our 10MVA 69kV/13.8kV Delta-wye Power Transformer. Our distribution voltage is 13.8kV. and Back-up Power is a 5 Units 2000kVA, 480V, 3P, Diesel Generating Sets which connected to our 13.8kV sytem thru 5 units Step-up...
electricpete, do you think a 90 to 105 degC winding temp is normal? It is already near to class F limits. I believe that the normal temp is around 70 to 85deg C. How can I check that the motor is designed for a SF continuous basis not for temporary overload?"
Hi guys,
We purchase a Altas Copco compressor coupled to a Siemens brand motor with nameplate data, 750 kw, 460 volt delta, 60 hz, 0.88pf, nominal efficiency 95.8% Full load Amphere(FLA)= 1100 amps, Service Factor(SF)= 1.15, SFA= 1300 Amps, RPM= 1788, Insulation Class F, Temperature rise 40...
jghrist,
Thanks, but the T/L is a Overhead one using ACSR cables. regarding the arresters we have the same brand in our plant but the other have no problem at all.
Hi, can someone explain to me this phenomena. We are connected to a 34.5kV Overhead T/L serving as our incoming power, distributed in 3-1MVA transformer, one in each 3 building. For the past years we haven't encountered surge arrester to blown out (fail). Last week during heavy rains one of our...
Guys, thanks for the information. However what type of arrester should we use a distribution type or a station type? what is the difference between the two? We have experirnce a distribution type arrester which blows up (the line and ground wire connection where detached on the arrester...
Hi, we have purchase a 2500kVA 13.8kV/440V Power Transformer connected delta-wye. The Primary High Voltage BIL rating is only 95kV... The Utility where we will connect the later is requiring a 110kV BIL at 13.8kV. Could someone explain to me the risk of installing a Transformer @ 95kV BIL to...
Guys,
Thanks a lot, especially to cuky2000 atleast i can support my claims that it will not be a problem with the cable..As per jbartos normally the problem will be the motor for it has a limitation with no. of start-up...
regards
Is a 50mm2 XLPE Power Cable rated 230A can withstand a starting current of a motor with a magnitude of 640A for about 3-5 cycles? Is is possible for us to have a 10-15 motor start-up/day... The power cables is rated for 90C continuous operation and can carry a 250C short-circuit rating. Is there...
Busbar, Yes this battery is for our swicthyard 115/13.8kV. Presently, we have a battery panel for each substation. However, we are now unitizing the control system and polanning to centralized DC Power supply.
Busbar, thanks for the info. Do you mean that even a sealed type maintenace free battery has a sulfuric acid emission... Will a galvanized enclosure will do? Instead of 316 Aloy
We are supposed to build a battery house with a 120V DC 60 units 2V 1000AH battery, However since we have a constraint regarding space, Is it possible that we make a Nema 3R Enclosure for this with a adequate ventilation. We are planning to use a maintenance free sealed type battery, Do we...
