Optimal selection of electric submeter installation location: the importance of staying away from electromagnetic interference sources

Sources and impacts of electromagnetic interference
The sources of electromagnetic interference are wide-ranging, including but not limited to large motors, transformers, high-frequency equipment, radio transmitters, and power lines themselves. Large motors and transformers generate strong magnetic fields when running, and these magnetic fields fluctuate with the change of current, forming electromagnetic noise. High-frequency equipment, such as inverters, radio communication equipment, etc., may emit high-frequency electromagnetic waves, which can penetrate space and interfere with nearby electronic equipment. Power lines, especially those that are not well shielded, are also important transmission media for electromagnetic interference.

When the electric submeter is installed near these interference sources, its internal electronic components, such as sensors, microprocessors, ADCs (analog-to-digital converters), etc., may be affected by the electromagnetic field, resulting in abnormal operation. The specific manifestations are reading fluctuations, increased measurement errors, and even equipment failures. For example, electromagnetic fields may interfere with the precise measurement of sensors, causing the current and voltage readings to deviate from the true values; interference with microprocessors may cause data processing errors, affecting the accurate calculation of electric energy; and the decrease in ADC conversion accuracy will directly affect the accuracy of the measurement results.

Optimization strategy for installation location
In order to avoid the impact of electromagnetic interference on the power sub-meter, the selection of installation location should follow the following principles:

Keep away from large electromagnetic equipment: First of all, try to avoid installing the power sub-meter in the direct vicinity of strong electromagnetic sources such as large motors and transformers. If the conditions cannot be completely avoided, consider setting a sufficient physical distance or using electromagnetic shielding materials for isolation.
Choose a low-interference area: Before installation, conduct an electromagnetic environment assessment and choose an area with low electromagnetic field strength for installation. This usually means staying away from high-frequency equipment, radio transmission towers, etc.
Reasonable wiring: The power line, signal line, etc. of the power sub-meter should use shielded cables as much as possible to reduce the coupling of electromagnetic radiation. At the same time, wiring should avoid parallel or cross with strong current lines to reduce the possibility of electromagnetic induction.
Install the grounding system: Good grounding can effectively discharge electromagnetic interference and protect equipment from damage. The power sub-meter should be installed with a grounding system that complies with the specifications to ensure that the grounding resistance is within the specified range.
Regular inspection and maintenance: Even if the ideal installation location is selected, the power sub-meter should be inspected and maintained regularly to promptly detect and deal with potential electromagnetic interference problems.