Our distribution grid is a Y-Y multigrounded system, so we plan to replace the few existing and old delta transformers feeding delta loads with standard Grounded Y-Y distribution transformers (500kVA to 3000kVA), with the star points solidly grounded on both side; a three wire circuit will feed...
We have a 24940GRDY system, (14.4kV L-G) and in order to avoid installing a MV single phase metering unit to feed a small 37.5kVA single phaseload requiring 2400V, we plan to use some units we have in stock, ie a step down 100kVA 14,4kV-120/240, and connect its 240V to the 240V LV of a 75kVA...
Our main distribution system is multigrounded Y ( 24940GrdY/14400V) but to feed our older 4160GrdY/2400V downtown system we typically use some 5MVA Delta-Wye transformers (24940D-4160Y). The 4160V system is typically well balanced. However, we need to remove some of the loads from it, and...
An industrial customer is currently fed via a 2000kVA 13860V delta-600 GrdY 347V. The medium term plan is to replace the 13860V system by a 24940GrdY system, and install a new 2500kVA transformer connected GrdY-GrdY
What would be the drawbacks to remove the present transformer (delta primary)...
I have a three phase pole mounted bank made out of 3 single phase transformers 100kVA 12470GrdY/7200-120/240V. The %Iz of each transformer is respectively 1.9%, 1.8% and 1.6% on the 100kVA base. The transformers are connected as a 12470GrdY-208GrdY bank (The 2 LV windings of each single phase...
There is an application for a GrdY-GrdY bank using 3 single phase transformers 14.4kV-120/240 into a 24.9kVGrdY-208GrdY bank.
2 of the units are 100kVA, with an 1.8% Iz and both will have their 120V LV winding paralleled; the third transformer is a 200kVA, same voltages, 2.2% Iz but only 1 of...
We are looking at installing a three phase transformer bank made out of 3 single phase oil filled transformers rated 167kVA each, to feed an small industrial load. The HV is a 4 wire system 24940GrdY14400V
The LV neutral will be connected to ground via an NGR
If we choose a Y-Y connection, I...
Looking at the ABB Distribution Guide page 63 and 64 and applying it to a GrdY-GrdY bank, it appears that a balanced three phase load will split evenly between the 3 phases. Am I correct in assuming that the currents in each phase will be different and proportional to the Iz of the individual...
I am looking for a good technical article discussing the use of transformers with different Iz (or voltage regulation)in a delta-delta, Y-delta, and GrdY-GrdY.
