In rare cases, customers need the WattNode input impedances, sometimes to drive the WattNode from a potential transformer, sometimes for other reasons.
The WattNode Vac terminals (green connector) have an input impedance composed of two parts: the power supply load and the sense resistors.
The power supply load appears between the “N” and “ØA” terminals on models with “-3Y” in the model number, and appears between the “ØA” and “ØB” terminals on the models with “-3D” in the model number. The power supply is the primary load for these terminals.
The “N”, “ØA”, “ØB”, and “ØC” terminals all have sense resistors that are 2.4 mega-ohm.
|WNC-3Y-208-BN, -MB, FT10||3.4k||3.4k||2400k||2400k||1.9 VA @ 0.79 PF|
|WNC-3Y-400-BN, -MB, FT10||13k||13k||2400k||2400k||2.2 VA @ 0.73 PF|
|WNC-3Y-480-BN, -MB, FT10||22k||22k||2400k||2400k||2.1 VA @ 0.69 PF|
|WNC-3Y-600-BN, -MB, FT10||68k||68k||2400k||2400k||1.1 VA @ 0.76 PF|
|WNC-3D-240-BN, -MB, FT10||2400k||13k||13k||2400k||1.6 VA @ 0.70 PF|
|WNC-3D-400-BN, -MB, FT10||2400k||61k||61k||2400k||1.6 VA @ 0.67 PF|
|WNC-3D-480-BN, -MB, FT10||2400k||86k||86k||2400k||1.7 VA @ 0.70 PF|
- These are conservative estimates for the power supply impedances. The actual values should generally be higher, but are also complex, because the power supply load is non-linear.
- The values for Pulse WattNodes are similar and generally a bit higher. Contact us if you need detailed values.
Current Transformer Inputs
The current transformer inputs all have a 23.0k input impedance between the white and black wires. Furthermore, the black terminals are referenced to the WattNode earth ground point through a resistance that varies from 20k to 60k.