460-480 Tyco Electronics, 460-480 Datasheet - Page 123

• Manufacturer Part Number: 460-480
• Description: Voltage Transformer
• Manufacturer: Tyco Electronics
• Series: 460r

Specifications of 460-480

• Turns Ratio: 4
• Transformer Mounting: Chassis
• Voltage Ratio: 480
• Primary Voltages: 480V
• Power Rating: 150VA
• Output Voltage: 120V
• Mounting Type: Foot Mounted
• Transformer Type: Voltage
• Lead Free Status / RoHS Status: na

Application Notes:
1.
2. Ferroresonance
3. Secondary Circuit Check
4. Primary Fuse Rating
Routine Factory Tests include: Polarity, accuracy, and partial discharge per CANADIAN
STANDARDS (CAN3-C13-M83)
(Partial discharge tests can also be carried out to IEC requirements on request)
ANSI BURDEN DATA
Voltage
Class
5kV
8.7kV
15kV
25kV
34.5kV
Delta Connected Supply Systems
When applying voltage transformers to ungrounded delta connected supply systems,
the transformer must not be connected in wye with the wye-point connected to neutral
ground, or ungrounded. The advent of zero sequence currents caused by a ground fault
in the system will cause damage, and eventual destruction of the transformer if the
fault is not removed quickly.
Most voltage transformers are lightly loaded, particularly when associated with watt
hour metering and relaying schemes. If the voltage transformer has one primary
lead grounded, and during an abnormal condition creating a large over-voltage,
the transformer may saturate, and its impedance may cause a resonance with the
system capacitance. This resonance, or oscillation, may be sustained and could destroy
the voltage transformer. If, however, the secondaries are connected in delta, with a
broken corner, and a suitable power resistor is connected across the broken corner,
then ferroresonance can be damped. Our recommendation for the resistive value is
shown on the catalogue sheet where it applies. The power rating is determined by
the use.
Immediately prior to connecting the burden and leads to the transformer, a check of
the impedance of that circuit should be made. This will avoid a possible short-circuit
connection to the transformer. If a short-circuit is applied to the transformer,
it can be withstood for one second.
NOTE:
a short circuit.
Values shown are suggested for normal installations, in order to protect the system
from a voltage transformer failure. Higher ratings at users option, may be used to avoid
unusual clearing due to conditions resulting from magnetising in-rush.
Burden
W
X
M
Y
Z
ZZ
No. of
Bushings
Only secondary circuit fuses can adequately protect the transformer from such
1
2
1
2
1
2
1
2
1
2
Connection
L-GND N
L-L
L-GND N
L-L
L-GND N
L-L
L-GND N
L-L
L-GND N
L-L
VA
200
400
12.5
25
35
75
2.5kV
2.5kV
2.5kV
2.5kV
2.5kV
2.5kV
2.5kV
2.5kV
2.5kV
2.5kV
LV
1 Min
60Hz
H2
1 Min
60Hz
10kV
NA
10kV
NA
10kV
NA
10kV
NA
10kV
NA
Power Factor
0.10
0.70
0.20
0.85
0.85
0.85
HV
1 Min
60Hz
NA
15kV or 19kV
NA
26kV
NA
34kV or 36kV Double Voltage
NA
50kV
NA
70kV or 80kV Double Voltage
15kV or 19kV
Double Voltage
26kV
Double Voltage
34kV
50kV
Double Voltage
70kV
Induced
18 Sec, 400Hz
Angle
84.3*
45.6*
78.5*
31.8*
31.8*
31.8*
123