Chapter 2: PTP 820G Hardware Description
Power Interfaces
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Power Interfaces
PTP 820G receives an external supply of -48V current via two power interfaces. The PTP 820G
monitors the power supply for under-voltage and includes reverse polarity protection, so that if the
positive (+) and negative (-) inputs are mixed up, the system remains shutdown.
The allowed power input range for the PTP 820G is -40V to -60V. An under voltage alarm is
triggered if the power goes below the allowed range, and an over voltage alarm is triggered if the
power goes above the allowed range.
Power Interface LEDs
There is an ACT LED for each power interface. The LED is Green when the voltage being fed to the
power interface is within range, and Red if the voltage is not within range or if a power cable is not
connected.
Figure 8 Power Interface LEDs
