Thank you all for your insights. Here are some answers to the questions raised (unable to get to this till this morning) that may shed some more light:
electricpete - the R2 X2 in the equation refer to the shorting bars only. Since this equation only applies to a standard induction motor, then...
Hi,
I have a unique question on what is the torque on a motor shaft if it is started while already spinning at full speed, but in the opposite direction. The real world case I am trying to analyze is: a pump storage hydro generator (38MVA synchronous machine with a squirrel cage winding on the...
OP - Can you clarify what protocol you are referring too? You say thatthere is no conversion of communication protocol, but Modbus and 61850 are not compatible, they are two different protocols regardless of the physical layer. Are you referring to different solution (SEL devices are an...
ccjc81 - If you can you be more specific in your question we can provide a targeted answer. Are you looking for offline speed, online speed, synchronizing, electronic governor, mechanical governor, etc. In general there are three ways that I am familar with on large machines to "measure" speed...
MODBUS is not designed for critical functions like breaker interlocking. For this you should use the IEC61850 protocol. A possible solution is to hardwire an output from the Modbus device and use a low end IEC61850 capable device as a converter and have it transmit the contact status via the IEC...
OM4 is a higher quality fiber and is backwards compatible to lower LED bandwidth cables (OM1 & OM2) so you should not have any problems with using OM4 fiber. Corning recommends the use of OM3 or OM4 (50u) for all legacy systems so you should be fine. But, to be sure you should contact the...
I won't comment on the code or liability issues. From a strictly technical perspective, the simplest and most reliable solution is to just replace the reversing contactor and the raise/lower/stop station with new devices with the same ratings, or slightly better. Electromechnical relays are very...
Hi,
I work in the utility industry and my company requires that ALL electrical drawings be PE Sealed. This inlcudes conduit, physical arrangement, schematic (Elementary, One-Line, Three-Line, etc), wiring drawings, equipment specifications, and they are looking to have PLC logic also PE Sealed...
Thanks rterickson and jghrist for the info.
Can either of you tell me what geographic areas you are using these connectors in? We are looking at using them in the North East US, with very heavy snow, ice/freezing rain, and temps -40 to 100 F. So these would see extreme cycling each year and I...
Hi,
Does anyone have any experince with this product? We are considering it in one of our 115/230kV switchyards and were looking for any feedback on it. Of particular concern is any long term deterioration of the conductivity across the swaged joints (hot spots, corrosion, bulging, etc.)...
Thank you for your responses.
Yes, this is a GE Frame 7 Combusiton Turbine application. We are using a fixed speed compressor with variable inlet vanes for flow control. Gas vent valve is based on high header pressure, but we just learned that the recycle valve is slow to open further...
Hello,
I am hoping that someone is able to help me. We are using a 2 stage motor driven Nuovo Pignone centifugal natural gas compressors (3x50% capacity - 2 normally running) to boost our ~190 PSI supply pressure up to about 480 PSI for a 7FA combined cycle power plant (2x1) and we are having...
Hi,
We are working on a project to replace an obsolete Fanuc 9030 PLC running a Nuovo Pignone gas compressor with new Mark VIe Controllers. The question I have is: are there 3rd party (non-OEM) companies out there that can supply a Mark VIe system or is the OEM the only source for it?
Thanks...
