Frequently Asked Questions - FAQs
72
Siemens Industry, Inc.
125-201
09/30/2019
Frequently Asked Questions - FAQs
One (or more) of the phase verification LEDs is red. What does this mean?
Any number of red lights indicates the MD-P1 or MD-P1D Power Meter are wired
incorrectly. Review the table in the
Phase Verification
section of this manual for a
description of the indicator lights.
How are the MD-P1 and MD-P1D Power Meters powered?
The MD-P1 and MD-P1D Power Meters are line-powered. An internal power supply
attached between L1 and L2 provides power to the units. Power lines are internally
fused.
Can the MD-P1 and MD-P1D Power Meters be used to monitor single-phase
loads?
The MD-P1 and MD-P1D Power Meters can be used to monitor single-phase loads.
See the
Installation
section for detailed setup information.
How many MD-P1 or MD-P1D Power Meters can be connected together?
Up to 20 MD-P1 or MD-P1D Power Meters can be connected together on a P1 FLN
network.
How is hexadecimal (HEX) to decimal converted?
Use the Decimal to Hexadecimal Conversion table in
Appendix A
of this manual. Meter
addressing is in hexadecimal.
What is true RMS?
RMS stands for "Root-Mean-Square." True RMS is the power from AC voltage/current
that will produce the equivalent amount of heat in a resistor as a DC voltage/current,
whether sinusoidal or not. For example, if a resistive heating element is rated at 15 kW
of heat at 240 Vac RMS, then the heat would be the same if we applied 240V of DC
instead of AC. A meter without true RMS will incorrectly read distorted waveforms.
How accurate are the MD-P1 and MD-P1D Power Meters?
The MD-P1 or MD-
P1D Power Meter’s accuracy is better than 1%.
What is the lead length for Rogowski Coil CTs?
The maximum lead length for the Rogowski Coils is 100 feet (30 meters).
How do I update the firmware?
Currently, the MD-P1 and MD-P1D Power Meters must be in USB mode to use
ViewPoint to update the firmware (either through the software switch or the rotary
switches). See
Appendix E
.