Covers topics related to the physical aspects of eGauge installation.
- eGauge Installation Examples
- Standard split-phase backfed
- Direct-feed Solar
- Three phase 120/208 or 277/480 Wye w/ single-phase inverter
- Monitoring 480V and 600V delta systems
- 120V or 240V Three-Phase Delta
- Three-phase High-leg delta
- Monitoring multiple services with one eGauge meter
- Monitoring 347/600V Services
- 3-Phase Inverter
- Panel phasing and eGauge installation
- Extending the length of the CT leads
- Protecting the eGauge with inline fuses
- Connecting directly to the eGauge
- Three-Phase installation tutorial
- Surges and overvoltage
- Sensor Hub and Sensors
eGauge Installation Examples
Wiring diagrams and basic configuration examples for installing the eGauge on different types of electrical systems.
The EG4xxx series meters are capable of monitoring up to 7 single-phase units (EG4015) or 15 single-phase units (EG4030) with a single meter. Single-phase units require 2 CTs each, one for each phase.
Please visit egauge.net/start for an overview of the physical installation and configuration process.
Example Wiring Diagram
Below is an example diagram of an EG4015 measuring 7 single-phase units on a distribution panel.
Ensure the meter's L1, L2, and L3 breakers are the same phases as the panels L1, L2, and L3 phases, or a phase-mixup will occur and recorded data will be incorrect. See this article for more information on phase checking.
The meter in the diagram shown below does not reflect the physical layout or dimensions of the eGauge meter.
Panel layout and installation will vary. The meter must be configured in software to match the physical installation before any data will be recorded.
A diagram showing the CT connections for the last 3 units from above may be found here.
In most submetering installations the same model CT will be used on all breakers. In this example, all CTs are set as 100A 20mm AccuCTs. If using CTid CTs, please click the blue CTid button to configure CTid sensors.
Registers define the data points the Gauge meter records. Each power calculation consists of a sensor input (S1, S2, S3...) that has the CT, and the voltage phase it is on (L1, L2, L3). Since each single-phase unit uses 2 CTs, there are 2 power calculations in each register added together to define the total usage of that unit.
Note, while the phasing pattern for units is typically staggered as L1 and L2, then L3 and L1, then L2 and L3, and so on, in the above example this changes with Unit 5 because the breakers for Unit 5, 6, and 7 begin on the right-hand side of the panel.
Standard split-phase backfed
Basic installation measuring power coming from a power utility (grid) and from a single-phase solar-system inverter
- With a single-phase inverter, the current flowing at any given instant on leg L2 is the negative of the current flowing on leg L1. Hence, rather than using 2 CTs on the inverter, simply multiply the negated value of CT3 with L2 to calculate the power on that leg.
- The totaling rules indicate that total usage (consumption) is calculated as the sum of the power reported for register Grid and, the positive-only register Solar+. If the power reported for Solar is negative (indicating that the inverter is consuming power, e.g., during the night), then total usage is simply equal to the power reported for register Grid. It would be (slightly) wrong to define the Usage totaling rule as Grid + Solar because in this case, the inverter’s consumption would be canceled out of the usage, giving a lower than real consumption figure.
Same as Standard Split-Phase installation, except that the inverter feeds directly into the power utility’s grid. That is, the Solar CT is closer to the utility than the Grid CTs. This situation often arises when solar power is delivered via a line-side tap.
- The only difference compared to the standard installation is that Solar+ was replaced by Solar- in the totaling rule for Usage. This is because the Grid CTs already capture total consumption, including any power coming from the solar system. The only exception is that when the inverter is consuming power (e.g., at night), that consumption is not captured by the Grid CTs. Adding Solar- corrects that because it will be equal to the amount of power consumed by the inverter, or zero when the inverter is producing power.
Three phase 120/208 or 277/480 Wye w/ single-phase inverter
Standard three-phase installation measuring power coming from a power utility (grid) and from a single-phase solar-system inverter. The color coding shows 120/208V, but applies to 277/480V as well. This diagram is for a Wye system with a neutral. Refer to delta diagrams for systems without neutral.
- Three-phase installations are set up the same as split-phase systems, except that a third voltage-tap (L3) and a third Grid CT is required to measure power flow on phase 3.
- With multiple inverters, add one Solar CT per inverter and define a separate register for each inverter (e.g., Solar 1 and Solar 2). Adjust the register definition according to the CT that is measuring the current and the phases that the inverter feeds onto. For example, CT5 measuring current onto L2 and also feeding onto L3: Solar 2 = S5L2 + -S5L3.
- If there are more than three single-phase inverters, it is more economical to measure the total solar output with one CT per phase.
Monitoring 480V and 600V delta systems
- Never attempt to connect the eGauge directly to a 480V delta or 600V delta service using the "Lx" and "N" terminals.
- Connecting an eGauge meter directly to a 480V delta or 600V delta service will destroy the meter. This is not covered under warranty.
- The eGauge requires a connection to the "N" terminal, failing to connect a proper "N" can result in device damage.
The eGauge is capable of directly measuring voltages up to 277V L-N (480V L-L). In the case of a delta system with no neutral, the maximum phase-to-phase voltage is 277V as the "N" terminal of the meter has one of the line voltages connected.
A 480V or 600V delta without a neutral may be monitored by the eGauge using EV1000 High Voltage Sensors.
The below diagram shows a 480V delta system. 600V delta systems may be measured in an identical manner.