Schweitzer Engineering SEL-351P, Быстрый старт

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7-42 Inputs, Outputs, Timers, and Other Control Logic Date Code 990215
SEL-351P Manual Técnico
close capacitor is charged higher than 20 Vdc, a point from which the close capacitor (and the
trip capacitor in parallel with it through a diode) can be charged at a faster rate by the capacitor
charger. The charger control in the SEL-351P boosts the capacitor charge rate via control line
terminals 2 and 10.
The final trip and close logic in Figure SECTION 7: .29 prevents the trip and close output
contacts from being energized at the same time. The magnetic actuator that opens/closes the
breaker is energized in one direction for a trip operation and the other direction for a close
operation.
The 24 Vdc available from terminal 1 whets the breaker auxiliary contacts. This 24 Vdc can also
be used to whet other inputs (e.g., opto-isolated inputs IN101 through IN107 – see
Figure SECTION 7: .1). Terminals 1 and 9 on CONTROL connector J5 provide the 24 Vdc and
return, respectively. The 24 Vdc should be limited to no more than 0.1 A and should be fuse-
protected.
The SF6 gas pressure is typically at 1.3 atmospheres (atm). If the pressure goes below threshold
setting SF6PRS (factory set at SF6PRS = 1.1 atm; access with SET G command), then Relay
Word bit SF6LO asserts to logical 1. The pressure going below threshold setting SF6PRS also
causes the ALARM output contact to pulse for 5 seconds (see Table 13.1 in
Section 13: Testing
and Troubleshooting ). The present SF6 gas pressure can be accessed with the STATUS
command (see subsection STA Command in Section 10: Serial Port Communications and
Commands ).
Pressure sensing in the SEL-351P has a 5 minute time constant with a 95% response. For
example, if the SF6 gas pressure is suddenly lost (recloser tank pressure goes from 1.30 atm to
atmospheric pressure, 1.00 atm), after 5 minutes the SEL-351P reports the SF6 gas pressure at
around:
1.30 - 0.95*(1.30 - 1.00) = 1.02 atm
This reported pressure is compared to setting SF6PRS. If it is below setting SF6PRS, then Relay
Word bit SF6LO asserts to logical 1. If Relay Word bit SF6LO is assigned to an output contact
(e.g., OUT102 = SF6LO), then the output contact asserts continually for this low pressure
condition.