Constant Current Regulartors, Ferroresonant design
Our 2 newest CCR's use the phenomenon of Ferroresonance to vary the voltage to maintain a "Constant Current" for the Airfield series loop circuits. This would be the "Christmas Lights" you see at any major airport airfield around the world. http://www.adb-air.com (ADB Airfield Solutions) has an excellent product support. These units have a Core type Transformer, capacitance, SCR and electronics that I need the schematic to trouble shoot. The load is the resistance. The older ones are "Thyristor" type which includes a large and small choke. From my limited knowledge, resistance is the conventional method for switching issues.
There is a ferro resonance situation where it's underground primary and pad mounts
Quote:
Originally Posted by
stiffneck
Our 2 newest CCR's use the phenomenon of Ferroresonance to vary the voltage to maintain a "Constant Current" for the Airfield series loop circuits. This would be the "Christmas Lights" you see at any major airport airfield around the world.
http://www.adb-air.com (ADB Airfield Solutions) has an excellent product support. These units have a Core type Transformer, capacitance, SCR and electronics that I need the schematic to trouble shoot. The load is the resistance. The older ones are "Thyristor" type which includes a large and small choke. From my limited knowledge, resistance is the conventional method for switching issues.
i am sure it's the same type situation where it's hi load from lighting, long length of cable and CCRs they have for airfield lighting. When you have great length of cable. The relationship on the power side is length of cable and KVA of a pad mount. You can't plug it in one at a time with elbows. Pad mounts with ferro situations have a switch where you can turn off the secondary load as you plug in your elbows, or the have a 3 phase vacuum switch set up, seen that. The engineer puts it in if its a ferro situation. And the equation is length of cable to the KVA of the can. And a bad situation is when the older guys plugged in a 3 phase pad mount and blew off the pinning bolts and high potted factories. The,way,it was explained to me the cable builds up like a capacitor and hi pots, when it gets one phase gets plugged in at a time with load, the cable builds up and hi pots. Either gang switch the 3 phase with a vacuum switch or kill the load before energizing. I am not a mathematician but there is,a,formula when you have ferro,situations. And on the prints they will highlight it on the circuit maps.
Is there a reason for wye wye?
Quote:
Originally Posted by
Lineman North Florida
We run into some overhead closed Delta banks that are fed by URD and we hang a fourth cutout with a solid blade in it and temporarily ground down the floating neutral while we are closing in the bank and then open 4th cutout when were done and it solved our issues.
Just built a ferro cutout for wye wye. I understand straight power,delta but wye secondary with a nuetral. It did have primary floating nuetral bus. Was that the reason?