Recent content by DTR2011

SEL-700 is a generator protection relay with multiple CT inputs and VT inputs. It has a large variety of available metering quantities and logging available. SEL-735 is a revenue grade meter with a single set of CT&VT inputs. The 735 has several power quality metering and event reports that...

Can you build up or down? You should really consult with a GIS vendor to see what’s possible. Where do plan to split the ring to add?

If you wire the CTs in a residual connection through the 4th CT input (Ig or In), you can see both. Our distribution company does this on a 351A application to have more ground elements available.

Make sure the floor is level. Make sure when the gear is installed that the gear is properly shimmed and level and the breaker cradle accepts the breaker properly. If you have remote racking and poorly leveled gear you will have a whole new set of challenges to deal with if something gets stuck...

Have you checked for DC ground faults? Many of them trace back to a transformer accessory.

MV indoor switchgear in ANSI world there is a device called a ground and test breaker. It is designed to rack into the front switchgear, in place of a breaker. There are 6 stabs, which are isolated from line/load and phase to phase. It is set up so voltage can be checked live or dead. Also...

If you are subject to any kind of regulation for testing, the test switches will pay for themselves during commissioning. I recall 20 years ago testing relays for multiple generator locations that did not have test switches. At the time, I had an electrician by my side to remove and land wires...

SEL

How about purging the space with nitrogen.

I don’t know much about the arcing horns, other than we remove them and the bus arrestors as part of a station rebuild. New Zno arrestors are installed on the lines. That smell of a new arrestor is almost sweet. We’re going through an asset renewal phase where OCB’s, disconnect switches and...

Maybe enough Sverker 900 fans can get Megger to accelerate the start up time of the unit. That’s my only issue with Sverker.

We’ve come a long way since these.

I haven’t seen or heard of these units in use in the United States. As you mentioned Omicron and Doble are popular. What are your needs? Automated testing or simple testing and a 3 phase source? My company has 6 Dobles and an Omicron. We also have 2 Megger-Sverker 900’s. The Sverkers are...

I know of an HVDC station that caused all kinds of problems with power line carrier systems, including the PLC based AMR system on the distribution lines.

How about testing with Doble at 120V and both parties are happy?