Hello,
I would like your thoughts on the following situation.
We are about to order an Air-Insulated, Metal-Enclosed, Medium-Voltage Switchgear according to IEC 62271-200.
The switching-device compartments are equipped with withdrawable Vacuum circuit-breaker.
The feeder earthing switch can...
Hi,
I need to write a "quality plan" to configure numerical protection relays in order to ensure a numerical relay is correctly configured.
This quailty plan would be like a check list with the different steps to follow.
The steps could be :
1. Identify relay hardware configuration , the...
Hello,
I would like to know if anybody has experience in electrical protection for double fed asynchronous machine for pump storage application and also for double fed asynchronous machine in general.
Which electrical protection are needed?
Which protection relays can be used (ABB, GE, SEL...
Hello,
We want to select a generator protection relay for a gas turbine starting with a Static Frequency Converter.
This relay must protect the generator during startup and normal operation.
The generator is used as a motor to start the turbine.
Once the turbine is started the generator...
Hello,
The problem is following: we have 2 redundant numerical differential protection relays for a generator step up transformer.
Each numerical relay has it own separated 125 Vdc power supply and lockout relay.
There are 2 separate channels.
We receive only one dry contact (not 2) for each...
Hello,
I would like your thoughts on the following situtation.
A steam turbine of 750kW (480V) had a governor failure and the steam valve was fully.
The load on the bus to which the turbine is connected was 1200 kW.
The intertie relay tripped on reverse power because active power was exported...
What are the electrical protections necessary for a 900 KVA induction generator connected to a steam turbine?
Is an asynchronous motor protection relay enough or is a synchronous generator protection relay necessary?
The loss of excitation protection 40Z is for sure not necessary.
In case of...
In motor protection relays, the thermal curve element (49TC) models the thermal capacity in a motor.
The 49 thermal element takes the load level and negative sequence current into account to creates a thermal model of the motor. Thus the thermal model creates an "equivalent current," Ieq, that...
Hello,
We have a unit connected generator.
The generator is 11kV, 9MVA and is medium impedance grounded (25 ohms).(high impdedance would have probably been better)
The generator is connected to 2 step up transformers of 5 MVA connected in paralell.
Both transformers are exactly the same and the...
Hi,
I want to replace an Out of Step Relay for Motors "MFOS 24" from Alstom.
I’am looking for a relay with the latest technology.
I can only find numerical protection relays who monitor the reactive power or the power factor of the motor to perform a motor” pull out” or “out step” protection...
Hi,
I ‘am looking for a “field application relay” (ANSI code 56) for synchronous motor with static excitation system.
The motor is a synchronous brush type motor of about 10MW with Direct Online Start.
The field is shorted with a resistor connected across the field at the start. The field...
Hi,
I'am looking for the instruction manual of the XASV autosynchronizer from Westinghouse.
It seems to be an old generator autosynchronizer. I can't find any information on the Web.
Thanks for your help.
Hi,
Does someone know what type of relay the following relays are?
Are they utility grade or industrial grade ?
Which brand it is?
They seem to be overcurrent relays and directional overcurrent relays but I could not find what INO, INH or IHS means?
Thanks for your help
Protection relay...
I would like your advice regarding generator under/overfrequency protection 81.
What are the recommended settings?
At which frequency should the generator be disconnected from the grid when the frequency is getting too high or too low.
I guess they depend on the size of the generator, of the...
Hi,
I'am new on this forum.
For generator protection, I would like to know what difference can be made between a 40Q and a 40Z loss of excitation protection?
40Q: is a loss of excitation protection that monitors the VAR flow.
40Z: is an impedance based loss of excitation protection.
What are...
