Potential Circuits - GE CEY51A Instructions Manual

GEK-1275
This data is for the 3.0-ohm basic-reach tap setting. The burden for other tap
settings may be calculated from the following equation:
Bnew
=
(B3 R -)2
x B3 ohms
where:
Bnew
=
Burden at new tap setting
B.R.
=
Basic reach of new tap setting
B3 ohms
=
Burden from Table V
POTENTIAL CIRCUITS
The maximum potential burden (with restraint tap set for 100%) imposed on each
potential transformer at 120 volts and 60 cycles is listed in Table VI.
TABLE V I
CIRCUIT R
X
P.
F.
WATTS VA
Polarizing
1300
-j680 0.89 8.7 9.8
Restraint 3200
jO
1.0
4.5 4.5
The restraint circuit burden, and hence the total rel ay burden, wi 11 decrease
when the restraint tap setting is less than 100%.
The potential burden at tap settings less than 100% can be calculated from the
following formula.
VA
=
(a
+
jb) Tap Setting 2
+
(c
+
jd)
100
The terms (a
+
jb) (c
+
jd), etc., represent the burdens of the mho-unit-
potential circuit expressed in watts and vars with their taps on 100%. The values
of these terms for 60-cycle relays are given in Table VII.
CIRCUIT
Restraint
Polarizing
TABLE VII
TERM
(Watts +
j
Vars)
(a + jb)
(c
+
jd)
12
TERM
(Watts
+1
Varsl
(4.5 + jO)
(8.7 - j4.5)