Can someone share the let-through curves for GE Current Limiting Fuses GF8B class L (800A to 2000A)
In addition I would like to ask how we can accurately read the logarithmic scale for the intermediate values for these let through curves.
Thanks
200hp, 480V motor tripping on instantaneous RS510 DigiTrip unit. Motor winding Insulation resistance above 50G-ohm and healthy winding resistance. Trip Unit is healthy and no issue with the cable. What else can cause this?
Note: Motor runs for 20-25 min before tripping.
We have an oil leak from GE AK-5A-75 breaker. The oil is leaking from the Gear Reduction Unit coupled to charging motor. We need to refill this but the manual says the type of oil is similar to Atlantic Refining Company Grade HFS#3. Can anyone share the data sheet for this type of oil or...
We have some critical 20hp motors. The motor starters have a MCP (motor circuit protector), NEMA Contactor and bi-metallic overload relay without any ground fault protection. I want to change the bimetallic overload relay with electronic overload relay that comes with ground/jam protection...
We have Seven large synchronous motors rated 23000hp with ABB Unitrol F excitation System. The motors are running with VAR control, Auto mode. on the Unitrol Control Panel, there is a percentage set point. This set point is called as "Reference Value" in ABB documentation. Usually, this...
A single phase fault in a 480V MCC led to 3-phase flashover. This flashover caused some other equipment to trip on Overvoltage on 480V switchgear feeding the MCC that experienced flashover. Can flashover in MCC cause overvoltage spikes upstream in 480V switchgear?
Can anyone provide me with the technical literature for Westinghouse BF84F relays 120/110V AC. The datasheets I have do not mention dropout and pick up voltage for the coil.
We have westinghouse BF84F contactor relay in one of the cabinet of a very critical system. The contactor have dual 115Vac input, primary source is energizing the coil and NO contacts whereas secondary source is connected to NC contacts of the contactor. In case of primary power failure, the...
Greetings,
I want to wire some of the breaker signals (breaker status, position, trip and close circuit)to a door mounted plug, so one side of the plug will be wired to the signal and the other side will go to the interface. Can anyone suggest me any suitable and decent looking control plug...
Greetings,
Can anyone confirm if there is clock function in GE MM-II relay. We have this relay on a motor feeder and it store just one last event but there is no time for the event. Also in the manual i could not find date and time. The software have for MM-II has installation problems.
Thanks
We are facing issues with our 90kVA UPS which is more than 25 years old. We connected Fluke 435 to the output of the inverter which recorded multiple events of Dips and Swells. We shifted the Fluke 435 to 480VAC UPS input side and recorded more than 6000 transients events on the fluke within 24...
We have dual redundant DECS-200 Baler's AVR for our synchronous motor excitation. I want to ask that usually for redundant units, when the master unit is working and it fails, the excitation will transfer to backup AVR (because the Internal and external Tracking is enabled). In case the motor is...
We have a 27000HP Synchronous motor operating at 13.2kV. The motor excitation control panel have redundant DESC200 Excititation Controller from Basler. During normal operation, if the Master fails, the excitation control will automatically transfer to backup controller. The motor was tripped on...
Hi,
One of our client is looking to check the effectiveness of its 30 year old grounding grid. Its basically a gas plant having multiple substations, power from multiple sources with total power demand over 150MW. What is(are) the best way(s) to analyse the grid integrity?
Thanks
Hi everyone,
We have multiple Ring Main Units connected together forming a loop as shown in the attachment. Its a 13.8kV Network. The Ring Loops are fed from a 13.8kV Switchgear, Bus-A is feeding one side of the loop while Bus-B is feeding the other side of the loop. Under normal condition, one...
Good Day,
I am considering to use IDEC control relays in the trip and close circuit of Low and Medium voltage Switchgear. Can any suggest me the model from IDEC whose contact rating will be good enough to be used in breaker trip/close circuit.
Thanks
I am working to design the first Generator Control Panel for Diesel Generators upto 2MVA. The Panel will be mounted on the Generator Skid. During a site visit I noticed the following components were part of one of the existing Generator Panel.
1. Air Circuit Breaker
2. Genset Controller
3...
Greetings,
We are working on a Diesel Engine Generator rated 13.8kV, 4785kVA. The unit was installed in 1980s. The generator have a static thyristor automatic voltage regulator from Brush Model#9603638. Please provide me with the Manual/Brochure for this AVR if anyone if you have.
Also I need...
I am interested to know about the advancement in smart metering for residential areas which in bigger picture shall be a part of Smart Grid. If anyone have worked on smart metering projects for residential areas, please share the leading manufacturers names, applicable standards from IEC / ANSI...
Greetings,
I had the opportunities to work on protection schemes and control schematics upto 33kV mainly for Industrial applications in Oil and Gas and other industrial sectors. My company is starting to move towards the design of HV System (69kV, 132kV) Protection schemes. I never worked on...
