EM3/EM3_250 Module
This module has its own microcontroller
Two models avaialbe:

The EM3 module with current transformer output of 1A.

The EM3_250 module with current transformer output of 250mA.
The EM3/EM3_250 module (datasheet 1A model) is a 4 quadrant energy meter, which bet on professional accuracy Class 1 Active and Class 2 Reactive and skip measurement deviations.
Some parameters must be configured before starting different measurements. In this section all of them will be defined.
Information about how to program this node using NodeRED can be found here. Otherwise, if you want to develop your own applications using the multilanguage API, please check here for more information.
Working mode configuration
1. Mode 0
It is the default mode configured in the module. In this configuration each phase is individual, and the computation of the three of them are the threephase variables.
As shown in the image below, it is possible to have three singlephase individual loads and see the measured parameters in one or threephase form.
2. Mode 1
If this mode is chosen, L1 is able to measure a threephase load. So, the module is able to measure a threephase balanced load as it was singlephase.
The current, power and energy parameters measured in L1 will be multiplied by 3 in each parameter, since it is a balanced threephase load.
3. Mode 2
If this mode is chosen, L1 and L2 are able to measure a threephase load. So, the module is able to measure a threephase balanced load as it was singlephase.
The current, power and energy parameters measured in L1 and L2 will be multiplied by 3 in each parameter, since it is a balanced threephase load.
4. Mode 3
If this mode is chosen, L1, L2 and L3 are able to measure a threephase load. So, the module is able to measure a threephase balanced load as it was singlephase.
The current, power and energy parameters measured in L1, L2 and L3 will be multiplied by 3 in each parameter, since it is a balanced threephase load.
Metering standard configuration
Three different metering standards can be chosen for the metering standard EM3/EM3_250 configuration: Circutor, IEC6205323 and IEEE.
1. Circutor
Parameters  1st Quadrant 
2nd Quadrant 
3rd Quadrant 
4th Quadrant 

Phase Current  +  +  +  + 
Cosinus  +    +   
Exported Active Power  .      . 
Exported Aparent Power  .  +  +  . 
Exported Reactive Inductive Power  .  .  +  . 
ExportedReactive Capacitive Power  .  .  .  + 
Imported Active Power  +  .  .  + 
Imported Aparent Power  +  .  .  + 
Imported Reactive Inductive Power  +  .  .  . 
Imported Reactive Capacitive Power  .  +  .  . 
Imported Active Power Demanded  +  .  .  + 
2. IEC6205323
Parameters  1st Quadrant 
2nd Quadrant 
3rd Quadrant 
4th Quadrant 

Phase Current  +      + 
Cosinus  +      + 
Exported Active Power  .  +  +  . 
Note
The rest of the parameters follow the signs defined in Circutor metering standard.
3. IEEE
Parameters  1st Quadrant 
2nd Quadrant 
3rd Quadrant 
4th Quadrant 

Phase Current  +      + 
Cosinus    +    + 
Exported Active Power  .  +  +  . 
Note
The rest of the parameters follow the signs defined in Circutor metering standard.
Full scale configuration
The voltage input of the equipment can be connected directly to the installation to be measured (as long as the voltage to be measured is not greater than 300VAC). This voltage value is computed using the neutral of the installation as a reference.
Voltage transformers
EM3/EM3_250 now supports voltage transformers (VT) of up to 36kVac. For the EM3/EM3_250 to work correctly with voltage transformers, the primary and secondary voltages of the transformer must be provided.
The current calculation is performed using a current transformer. Current transformers have an output current that must match the module model we have. This current can be 1AAC or 250mAAC (not worth 5AAC).
Current inversion
EM3/EM3_250 now supports current inversion. It toggles the current direction of any phase, to avoid modifying connections already installed.
Warning
It is very important to properly configure the full scale values for current and voltage. If not, the measured parameters will not be correct.
Voltage transformers and current inversion new in eManager image release 22.10.
Functionalities
This module can provide 2 different groups of parameters: energy and power. In the table below are shown the parameters related to each group.
Power Parameters  Energy Parameters 

voltage  active_energy 
current  aparent_energy 
frequency  inductive_energy 
cosine  capacitive_energy 
angle  exported_active_energy 
active_power  exported_aparent_energy 
aparent_power  exported_inductive_energy 
reactive_power  exported_capacitive_energy 
exported_active_power  imported_active_energy 
exported_aparent_power  imported_aparent_energy 
exported_inductive_power  imported_inductive_energy 
exported_capacitive_power  imported_capacitive_energy 
imported_active_power   
imported_aparent_power   
imported_inductive_power   
imported_capacitive_power   
maximeter   
current_full_scale   
voltage_full_scale   
It allows getting a subgroup of parameters relative to the instant POWER on:
 Phase One (alias "L1").
 Phase Two (alias "L2").
 Phase Three (alias "L3").
 The combination of three phases (alias "L123").
It allows getting a subgroup of parameters relative to the accumulated ENERGY on:
 Phase One (alias "L1").
 Phase Two (alias "L2").
 Phase Three (alias "L3").
 The combination of three phases (alias "L123").
It also allows getting the eight subgroups of parameters above, ALL together.
Note
Energy meters can be set back to 0, with the reset command.
LED's overview
In the image below a representation of the EM3/EM3_250 LED's behaviour is shown. The P axis corresponds to the active power, while the Q axis corresponds to the reactive power.
The LED's have 4 possible states, where different states shown in which Quadrant is the EM3/EM3_250 working and the range of the cosinus:
 Green: cosinus is between 1 and 0.8 (Quadrant 1) or between 1 and 0.8 (Quadrant 4).
 Flashing Green: cosinus is between 0.8 and 0 (Quadrant 1).
 Red: cosinus is between 0 and 1 (Quadrant 2) or between 1 and 0 (Quadrant 3).
 Flashing Red: cosinus is between 0.8 and 0 (Quadrant 4).