Installation
Checking Phases
24
Siemens Industry, Inc.
125-201
09/30/2019
System Values
System values are the sum of L1 + L2 + L3 measurements. System values may not be
meaningful since two different devices or loads can be monitored by a single MD-P1 or
MD-P1D Power Meter element.
When paired with the correct voltage phase, each CT provides individual kW/kWh
readings for that CT channel.
Checking Phases
The CT phase-checking LEDs are a unique feature of the MD-P1 and MD-P1D Power
Meters that simplify installation by ensuring proper CT-to-phase installation and
avoiding faulty data collection. The power meters automatically adjust for CT
orientation
—reducing set-up time and nearly eliminating installation errors.
Verifying the MD-P1 and MD-P1D Power Meters
Setup Using the LEDs
The MD-P1 and MD-P1D Power Meter have three bi-color LEDs for each element.
These LEDs provide the following information:
● All LEDs are green — the system power factor is greater than 0.55 and the CTs
are properly placed on the corresponding voltage phases.
● Any one LED is red — there is a phasing connection error.
● Two LEDs are red and one is green — two CTs are reversed.
● All three LEDs are red — all CTs are incorrectly connected.
If the total system power factor is less than 0.55, the LEDs are red even if connected
properly. This situation is rare but can occur if, for example, the load to be monitored
is a lightly loaded electric motor where it is common for the power factor to be less
than 0.55 and the corresponding LEDs will be red.