gefran TPD32-EV-...-4B - Table A.1.6.3.1: Calculation of the Configuration of Dip-Switches SW3-1 to SW4-8 for Standard TPD32-EV-.. Drives with External Bridge

—————— Instruction manual ——————
485
Validformulas
Vb@Id
N=(IdN/(Iprim/Isec))xRb  and Gain_required=Vf@IdN/Vb@IdN.
Calculation example A
IdN=2000A,CT=2400A/0.5A;Rb=5Ohm.
Vb@IdN=(IdN/(2400/0.5))xRb=(2000/4800)x5=2.08333V;
Gain_required=Vf@IdN/Vb@IdN=0.612/2.08333=0.29376;therefore
Binary_switch_setting=51.2/0.29376=174.29whichisroundedoffto174andconvertedintobinaryformat
as000010101110.i.e.:
SW3-1 SW3-2 SW3-3 SW3-4 SW4-1 SW4-2 SW4-3 SW4-4 SW4-5 SW4-6 SW4-7 SW4-8
OFF
MSB
OFF OFF OFF ON OFF ON OFF ON ON ON OFF
LSB
Calculation example B (extreme case)
Id
N=85A,CT=2000A/1A;Rb=2.5Ohm.
Vb@Id
N=(IdN/(2000/1))xRb=(85/2000)x2.5=0.10625V;
Gain_required=Vf@Id
N/Vb@IdN=0.612/0.10625=5.76;therefore
Binary_switch_setting=51.2/5.76=8.88888roundedoffto9andconvertedintobinaryformatas000000001001.
Calculation example C
IdN=16000A,CT=20000A/5A;
Usinganinternal2.50-OhmRB,insertingasecondCT2witharatioof5A/1A.
ThenewIprim/Isecisthetotalof20000A/1A;
Vb@Id
N=(IdN/(20000/1))xRb=(16000/20000)x2.5=2V;
Gain_required=Vf@Id
N/Vb@IdN=0.612/2=0.306;therefore
Binary_switch_setting=51.2/0.306=167.32roundedoffto167andconvertedintobinaryformatas000010100111.
Calculation example D
BurdenresistorconnectedtoterminalsXCTandCTwitha5Asecondarycurrent.Applyingthesamecriteria
fortheburdenresistor,theidealburdenresistorvalueis2.5Ohm/5=0.5Ohm.ThenearestvaluefortheEIA
E96seriesis0.499Ohm±1%butthemorecommonlyused47Ohm±1%canofcoursealsobeused.
IdN=8000A,CT=10000A/5A,Rb=0,47Ohm.
Vb@Id
N=(IdN/(10000/5))xRb=(8000/2000)X0.47=1,88V;
Gain_required=Vf@Id
N/Vb@IdN =0.612/1.88=0.3255319149;therefore
Binary_switch_setting=51.2/0.3255319149=157.281;roundedoffto157andconvertedintobinaryformatas000010011101.
note: Whenchoosingtheexternalburdenresistor,bearinmindthepossibilityofsubstantialpower
dissipation.Inthisexample,thepowerattheratedcurrentisalreadyapprox.(1.88)
2
/0.47
=7.5Wwithouttakingintoaccountanyoverloadconditionsortheadvisabilityofnotusing
resistorsatmorethanhalfoftheirratedpower.
Table A.1.6.3.1: Calculation of the configuration of dip-switches SW3-1 to SW4-8 for standard TPD32-EV-.. drives with external bridge
Rated arma-
ture current
CT
transformer
Jumper J4 (on
the FIRXP-XX
card)
Jumper J5 (on
the FIRXP-XX
card)
Vb@IdN Gain
required
Binary
switch
setting
Binary
number
SW3-1, ..SW3-4,
SW4-1, ..SW4-8
(on the FIRXP-XX card)
[
adc] (Rb=5Ω) [Vdc] [MSB … LSB]
1000 1600/0,4 OFF ON 1,250000 0,489600 105 1101000 000001101000
1010 1600/0,4 OFF ON 1,262500 0,484752 106 1101001 000001101001
1200 1600/0,4 OFF ON 1,500000 0,408000 125 1111101 000001111101