CURRENT SENSING - IMPROVED VOLTAGE REGULATION KIT (SC MACHINES ONLY) The standard machine is voltage sensed and if required current sensing can be added to make the machine more flexible to improve the voltage regulation where semi-conductor or thyristor loads are used which distort the voltage waveform of the machine.  This unit can also be used to impact on the sensing circuit of the A.V.R. to overcome voltage drops where long  cables  between  the  generator  and  load  are  used.    The  unit  consists  of  a  current  transformer  C.T.  and  burden resistor.  See Fig. 20. The components are identical to those used for the quadrature droop kit for Parallel Operation, the only difference is that the circuit is arranged to be more sensitive between unity to 0.8 p.f. (lag) loads. Fig. 20.  Auxiliary Terminals (See Note 2) NOTES: 1. Depending  on  machine  type,  one or   more   main   stator   cables   are connected to each output terminal, insert improved regulation C.T. on one cable only. See  Fig.  21  for  C.T.  position  and wiring diagrams. 2. Connect  to  auxiliary  terminals  2  - 8   (after   removing   link)   on   two phase sensed machines and 4 - 7 (after    removing    link)    on    three phase sensed machines. A.V.R. Stator Connection Improved Voltage Type (Standard phase rotation) Regulation Fig. C.T. Position Two Phase 4 Wire & 6 Wire Star 20 V2 Series Star 20 V2 Sensed 12 Wire Series Delta 20 V2 Parallel Star 20 V2 Series Zig-Zag Star 20* W2 Three Phase 4 Wire & 6 Wire Star 20* V2 Series Star 20* V2 Sensed 12 Wire Series Delta 20* V2 Parallel Star 20* V2 Series Zig-Zag Star 20* U2 Fig. 21.  Improved Regulation C.T. Positions NOTES: 1. *For  these  stator  connections  the  C.T.  secondary  leads  S1  and  S2  must  be reversed for correct machine operation. 2. Standard  phase  rotation  is  U.V.W.  when  a.c.  generator  is  rotating  clockwise viewed   at   the   drive   end.      For   phase   rotation   U.V.W.   when   rotating   anti- clockwise refer to factory for details. Resistance Values Burden Resistor - 1000 ohms C.T. Secondary - 16 ohms 39