P.2.6
SEL-411L Relay Protection Manual Date Code 20151029
Installation
Shared Configuration Attributes
The relay samples the optoisolated inputs at 2 kHz—see Raw and Filtered
Data on page P.8.2.
Control Outputs
I/O control outputs from the relay include standard outputs, hybrid
(high-current interrupting) outputs, and high-speed, high-current interrupting
outputs. High-speed, high-current interrupting outputs are available only on
the optional INTC or INTE I/O interface boards. An MOV (metal-oxide
varistor) protects against excess voltage transients for each contact. Each
output is individually isolated, except Form C outputs, which share a common
connection between the NC (normally closed) and NO (normally open)
contacts.
The relay updates control outputs eight times per cycle. Updating of relay
control outputs does not occur when the relay is disabled. When the relay is
reenabled, the control outputs assume the state that reflects the present
protection processing.
Standard Control Outputs
NOTE: You can use ac or dc circuits
with standard control outputs.
The standard control outputs are “dry” Form A contacts rated for tripping
duty. Ratings for standard outputs are 30 A make, 6 A continuous, and 0.5 A
or less break (depending on circuit voltage). Standard contact outputs have a
maximum voltage rating of 250 Vac/330 Vdc. Maximum break time is 6 ms
(milliseconds) with a resistive load. The maximum pickup time for the
standard control outputs is 6 ms. Figure 2.3 shows a representative connection
for a Form A standard control output on the main board I/O terminals.
Figure 2.3 Standard Control Output Connection
See Control Outputs on page P.1.13 for complete standard control output
specifications.
Hybrid (High-Current-Interrupting) Control Outputs
The hybrid (high-current-interrupting) control outputs are polarity dependent
and are capable of interrupting high-current, inductive loads. Hybrid control
outputs use an IGBT (Insulated Gate Bipolar Junction Transistor) in parallel
with a mechanical contact to interrupt (break) highly inductive dc currents.
The contacts can carry continuous current, while eliminating the need for heat
sinking and providing security against voltage transients.
With any hybrid output, break time varies according to the L/R (circuit
inductive/resistive) ratio. As the L/R ratio increases, the time needed to
interrupt the circuit fully increases also. The reason for this increased
interruption delay is that circuit current continues to flow through the output
MOV after the output deasserts, until all of the inductive energy dissipates.
Maximum dropout (break) time is 6 ms with a resistive load, the same as for
the standard control outputs. The other ratings of these control outputs are
NOTE: EA certified relays do not
have MOV protected standard
output contacts.
Equipment damage can result from
connecting ac circuits to hybrid
(high-current-interrupting) control
outputs. Do not connect ac circuits to
hybrid control outputs. Use only dc
circuits with hybrid control outputs.
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