The Three-phase networks without neutral also known as networks 3P3W or 3 wiresare a type of electrical installation where only the three phases are available, without a neutral conductor.
Although they often go unnoticed, these types of networks are still very common in numerous industrial and energy environments, which is why it is essential to use measuring equipment specifically prepared for this type of configuration.
Where are three-phase networks without neutral used?
3-phase 3-wire configurations are especially common in:
- Industrial facilities
- Motors and three-phase loads
- MV/LV distribution networks
- Naval systems
- Power generation
- Old electrical panels
- International applications (especially in the USA and heavy industry)
In this type of installation, there is no neutral reference, so electrical measurements are taken directly between phases.
What are the differences between a 3P3W network and a 3P4W network?
In a three-phase network with neutral (3P4W), equipment can measure:
- Phase-to-phase voltages
- Phase-neutral voltages
- Currents per phase
- Imbalances with respect to neutral
However, in a three-phase network without a neutral:
- Phase-to-neutral voltages cannot be measured.
- The voltage reference is taken only between phases
- The analyser or counter must be specifically prepared for 3P3W configuration
Furthermore, depending on the type of installation, 2 different measurement methods can be used:
- Aron method, or 2-element method
- 3-element method
Therefore, not all devices on the market work correctly on these types of networks.
Common problems in incompatible devices
Many basic analyzers and meters are designed only for networks with neutral, or 3P4W, which can cause problems in 3P3W installations:
- Neutral for power supply required
- Incorrect voltage readings
- Loss of energy measurement accuracy
- Impossibility of calculating certain variables
- Limitations in monitoring and alarms
- Errors in old or international industrial installations
In critical applications, this can translate into incorrect diagnoses or loss of energy control.
SACI analyzers compatible with three-phase networks without neutral (3P3W)
SACI analyzers enable work on both three-phase networks with neutral (3P4W) and without neutral (3P3W), adapting to different industrial and energy environments.
- SAM3000: Multifunction network analyser ready for industrial installations and advanced energy monitoring.
- SAM3001: Equipment aimed at electrical supervision and control of energy parameters in three-phase installations.
- AHM1: Multifunction analyzer compatible with different network configurations.
- AHM3: Advanced solution for electrical measurement and analysis in industrial environments.
- ASM3-PV: Analyzer designed for photovoltaic installations and energy applications with advanced communications.
SACI meters compatible with 3P3W networks
SACI also has energy meters that are compatible with three-phase networks without a neutral.
- TCIL2: Three-phase meter – analyzer ready for different installation configurations.
- TCIL1: Simple equipment for energy measurement in industrial and tertiary applications.
- TCIDL3-MID: Certified MID meter compatible with 3P3W and 3P4W three-phase networks.
- TCIDL2-MID: MID Solution for reliable energy measurement in installations without a neutral conductor.