Hi all,
Probably a stupid question, but . . .
I'm spec'ing out a 480V MCC lineup to replace an existing one that is at end-of-life. Getting a Rockwell Centerline MCC with all the bells and whistles, E300 overloads etc. Going thru the approval dwgs now.
3000A Main CB has an LSIG trip unit...
Hi,
Had a question about contact ratings related to a simple circuit . . .
In a new substation being built I have a SEL-2506 I/O module with 125Vdc inputs for wiring in miscellaneous building alarm contacts (125Vdc battery charger alarm, HVAC alarm, etc). Additionally, an H2 detector is being...
Hi all,
I am designing a project and am coming across some frustration dealing with interposing relay contact ratings. Any help would be appreciated.
Problem 1. I have a 4kv switchgear breaker I am replacing the relaying on. Due to some design considerations, I need to use interposing...
All,
I was wondering if anyone knew / understood why IEEE1547 is so specific about requiring phase-to-phase voltage detection for 27/59/81 tripping? (It of course gives the caveat that phase-to-neutral voltage can be used if the utility and DG are connected by a wye-wye grounded or single...
Are there any good relay guys out there that can give me some comments on the following.
At one of our facilities, we have a large cross compound unit connected generator, HP and LP approx 300MW / 20kV each. It is high impedance grounded with the neutral transformer with secondary resistor...
Hello,
Are there any good relay guys out there that can help me out with the following? I am trying to figure out how tap settings are determined for a KD-10 relay at a MTA other than nameplate. I know how to come up with settings at nameplete MTA using the formula ST/(1+-M).
So for a KD-10...
Can anyone give me some guidance or point me to some technical papers regarding the use of medium voltage breakers vs starters based on starts/stops a day?
All of my company's power plants were built in the 1950s and 1960s and were originally baseload. All 4kV motors were supplied from...
The plant I work at has recently had some issues with battery grounds (equipment misops, false indications, etc). We are fairly effective at locating and removing them but usually we don't notice them until a problem has occurred. Aside from increasing operator surveillance of battery grounds...
