Schweitzer Engineering SEL-351P, Быстрый старт

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8-20 Breaker/Recloser Monitor, Battery System Monitor, Date Code 990430
Metering, and Load Profile Functions
SEL-351P Manual Técnico
This SEL
OGIC
Control Equation permits automatic reclosing to proceed after a reclose interval
time out only if all the following conditions are present:
•
Trip and close capacitors charged
•
The battery charging board is okay; BCBOK = logical 1
•
The battery is connected/not failed; NOBATT = logical 0
•
The battery has not failed the load test; DTFAIL = logical 0
This is a factory default setting because recloser tripping and closing requires dc battery energy.
Therefore, if the batteries or charging system are not functioning properly, the control should not
reclose after a trip because there might not be enough dc battery energy to trip again after a
reclose. See Figure 1.30 in
Section 1: Factory-Set Logic .
M
ETERING
The SEL-351P reports metered values in several formats through the front panel and through
serial communication port interrogation. You can use the front-panel METER pushbutton and
select INST, or use the serial port METER command to view instantaneous values of phase and
residual current, phase voltage, per phase and three phase real and reactive power, per phase and
three-phase power factor, current and voltage sequence components, and frequency.
If you need accurate voltage and power metering, you must connect three-phase voltage to the
control from a set of potential instrument transformers. You use the EZ Level SET EZ command
to set the PT Ratio to reflect the ratio of these potential instrument transformers. If you connect
only single phase, 120 Vac to power the SEL-351P, the factory-wired terminal strip jumpers
route this voltage to the VA phase voltage input. The VA phase voltage input is needed to
measure system frequency, but the 120 Vac power source may not reflect accurately the primary
voltage and may not even be connected to primary Phase A. Therefore, with only single-phase
voltage connected to the SEL-351P, the voltage and power metering values reported by the
SEL-351P will not represent accurately primary voltage and power flow.
The metered values of current reflect the primary current scaled through the current transformers
in, or on, the recloser. You use the EZ Level SET EZ command to set the CT Ratio of these
current transformers. The factory wiring in the SEL-351P assumes that the Phase 1-2 recloser
bushings are connected to primary Phase A, Phase 3-4 to primary Phase B, and Phase 5-6 to
primary Phase C. If this is not the case, you will need to modify the SEL-351P terminal strip
connections to obtain the proper phase and phase polarity.
In addition to instantaneous metering, the SEL-351P metering functions include Demand
Metering, Energy Metering, and Maximum/Minimum Metering.