Hi, We had Bus Bar Differential operated during Transformer Energisation ( 75MVA)
THe CT's are measruning input & output currents for Bus Differential
Has someone observed similiar issue. The Bus is healthy & also teh Transformer.
Thanks in advance
The Main Power Transformers in the Facility are provided with Deluge Fire Protection system. Is it mandatory to Test & release huge amounts of water on running Transformer. Is there any Standard for Deluge Testing on running transformer
Thanks
I am talking about Middle east. The Ground fault protection is for HVAC System for Substation, plant buildings etc. The HVAC system is designed with two compressor units with controls.
I have Thermistor protection relay Siemens 3UN 2100-0AF7, please can you tell me how it works. During testing it activates once Sensor is disconnected. During testing when we simulated temperature by increasing resistance we could not activate this device.
Please let me know in detail how it...
Is there any standard which includes ground fault protection of HVAC system. The HVAC system includes blower motors, compressors etc. Is it enough to provide GFCI.
The Plant I am referring in Air Separation plant with Compressor Motors. The design is available in only one of three plants. This design where unavailability of DC power in Substation will cause total power failure is also not helping in case we need to change the DC Charger, which is a future...
We have plant commissioned in 1999, this has switchgear breakers which have interlock for DC supply i.e in case DC power is off the breaker will be open. Is this a Standard requirement.
Please let me know any standard which has this requirements, we need to remove this interlocks.
Thanks in...
Hi all,
We have 34.5 KV switchgear with Bus Bar protection relay 7UT6 ( Siemens Siprotec)
The system has incomer & around 4 outgoing feeders. The system is working fine till recently when the new feeder for different plant was connected. The feeder was energized & minimum load was available...
We have new Project for Which motor Solo run test done & motors failed on high bearing temperature. Is there any standard which asks some strict compliance before going ahead again for Solo run test. Definitely the issue of high bearing temperature to be resolved.
Best regards
Hello
I have a doubt regarding The circuit breaker close permissive indication "CB READY". We have some interlocks downstream & they are not taken in logic of CB ready, so in case there is no close permissive the CB ready indication appears. Please need to know the part of standards which say...
I experienced failure i.e total black out of ABB manufactured PLC AC 31 used for Excitation panels. This issue happened with Two excitation panels.
The PLC's were replaced reprogrammed & machine started. The investigation is on regarding to root cause of PLC failure. Did anyone experience the...
Hi!
We have ABB RXPD 21H OUT OF STEP RELAY ( LOSS OF EXCITATION).The relay is used for 19.3 MW synchronous motor. From last two months the machine is tripped two times due to this relay activated. Though the parameters such as load & voltage are within range. Please can anyone highlight the...
Hi!
I have a question regarding UPS loading, can common load be supplied by two independent UPS. The common load is instrument servers. I have a doubt about synchronization of UPS outputs. What if the supply for both UPS is connected at some point.
Thanks
We have a dry type transformer 225 KVA,480/220/127 Vwhich is installed in shade, which is open from all sides, we need to replace the shade with closed room. The transformer is vented type ( with openings for air circulation). If we make closed room with split AC installed in that room, would...
We have a excitation panel for compressor motor ( 4.8MW),there was a fluctuation for electrical parameters. The excitation panel was running in FCR mode. The mode was changed from FCR to VAR regulation mode. As soon as mode was changed the exciation paramters (Excitataion voltage & current)...
I need to calculate undervoltage of exisitng transformer. rating : 75 MVA,34.5/13.8 KV, rated current at 13.8 KV =3137.8 A. The undervoltage is due to starting a compressor motor of 7.5 MW, 351 Ampere Induction motor on Direct on line start. The transformer is ruuning already with 50 MW load...
It is benefecial to have the medium voltage installations such as 34.5KV GIS installed in a room with Ventilation fans.The leak can be either a small leak or due to any fault inside switchgear. There are in each cubicle flappers which are places from where high pressure gas will be released...
