I am looking for a standard number (prefarable IEC, but reference to any other standard would also be helpful) regarding the numbering of panel-wires. M is for instance a motor circuit, C10 a protection CT circuit on the red phase, B a busbar CT circuit, J the DC control voltage, etc. Thank you...
I am doing a three phase and a single phase to ground fault calculation on the secondary side of a transformer. But the answers I obtain from my software-program and the answers from my hand-calculations (invinite bus) are not the same - somewhere I am doing something wrong.
Trsf data:
Rating...
We have two motors on a conveyor belt (Each 50kW) How do you determine the time-delay between the start-up time of the two motors? (DOL-starters) I don't want to start both imediatelly (due to the high start-up current), but I also don't want the time-delay between the start-up of motor1 and...
I want some data on some old WRIM-motors we use in our plant, to check their settings. The manufacturer doesn't exist anymore, so I don't know where to obtain the data. Can I assume any values or is there any average value I can use for:
1. Safe hot stall time?
2. Permissible start attemps /...
Hi all
Is there any way how you can determine the kneepoint of a protection CT with the nameplate values?(IEC ratings) To determine the kneepoint with a voltage source and a ammeter is no problem - I want to know if it is possible to find it mathematically.
Thanks
I have a question re relay coordination on electromechanical IDMTL earthfault relays.
Take a system with 10P10 1000/1 CT's.
Relay is 2xOC and 1xEF.
Take a earth fault setting of 10%, meaning that the relay will pick-up at 100A. Most relays claim to be effective up to x20 plugsetting, in this...
What is the time interval between a high-set (instantaneous) unit and IDMT-relay? I know time between relay-relay is 0.3 - 0.4 seconds, is it the same between high-set and relay or not?
Thanks
On our conveyors we have slipringmotors. Some of the conveyors have just one motor, the longer belts have up to three motors. On all our motors we have vapourmatic starters, but with statormatic probes. (Each motorstater have three steps to bring the drive on speed)
The motor sizes varies from...
We are using diesel-electric trucks in our mine. (open-pit) When the trucks take some inclines, they use overhead lines, or pantograph lines, to supply them with electricity.
It is 1600V DC, and it is supplied through 1440kW 11kv/1200V 3ph transformers, and then rectified with a three phase...
