Possible Causes



1. Balanced Load

If the loads are balanced, the currents on the individual conductors feeding the loads will be equal and will cancel out when summed, resulting in a lower current at the main conductor.

2. Power Factor

The power factor of the loads can affect the current readings. If the power factor is high, the current will be lower for the same amount of power consumption.

3. Current Transformer Issue

If a current transformer (CT) is used to measure the current at the main conductor, a faulty or improperly installed CT can provide inaccurate readings.

4. Leakage Current

Small amounts of leakage current can flow through insulation or equipment, which can reduce the current measured at the main conductor.

5. Capacitance or Inductance

Capacitive or inductive loads can introduce phase shifts in the current, which can affect the readings at different locations.

6. Loose or Corroded Connections

Loose or corroded connections can increase resistance and reduce the current flow, resulting in lower readings.

7. Cross-feed Between Phases

If there is unintentional cross-feed between phases, current can flow between them, reducing the current on the original phase.

8. Measurement Error

Ensure that the measurements are taken correctly with calibrated instruments and that the conductors are properly identified.

Troubleshooting Steps:1. Verify the balance of the loads.
2. Measure the power factor of the loads.3. Check the current transformers for proper operation and installation.
4. Inspect insulation and equipment for leakage current.5. Examine the circuit for any capacitive or inductive loads.
6. Tighten or replace any loose or corroded connections.7. Verify that there is no cross-feed between phases.
8. Repeat the measurements with accurate instruments and proper procedures. Flag for review