A test was recently performed on a high impedance bus differential scheme and we are struggling to understand the reason for the result.
The scheme is set to operate at around 300 Volts. A voltage source was used to raise the voltage on the diff circuit for the A phase, and it tripped at the...
Does anyone know a way of limiting the number of columns in excel ?
The reason is that I make up spreadsheets and use names like (for example) CTR3 for cells.
We have recently moved to excel 2010, and there are more columns available so these are now cell references and can't be used as names...
All our protection and metering equipment uses 63.5/110 Vac secondary (or 120 V in some parts)
In my part of the world, below 50Vac is considered ELV, and 110 V needs to be treated the same as 999 volts.
When I first started out 110 V was considered safe, but times have changed
There doesn't...
I am not sure if anyone can help, but I will give it a try.
I help run training courses on protection relays - we have a section where we get the students perform a simple settings study using a CDG11 curve.
The graph we use just shows the operating times when the time multiplier is set to 1...
Hello
I produce spreadsheets that determine testing points based on some given parameters.
For one particular device, there is a parameter that is rounded to the nearest 0.05 - the setting software used allows it to be entered to the nearest 0.01 - and it is rounded internally.
So most of the...
There is a bit of debate within our organisation about transportation of protection panels with the relays installed.
Some people want to wire and test protection panels in the workshop, then transport the panels to the site with the relays in place. They relays are mainly modern numerical...
Hello All
A colleague of mine was recently testing a 415/110 V 3 limb VT. When injecting phase-phase on the 415 V side using a variac the secondary measurements were hopelessly out, but if a full three phase injection was performed with a test set then the secondary measurements were as you...
