Compact and very easy to install. Simple DINRail Mounting. Wires pass through 13.7mm (0.5 inch) diameter tubes in the meter body Will accept 22 AWG 1 AWG wire. There are two screws that pierce the insulation of the wires that pass through the meter. The meter comes with two sets of bushings for medium and small wire diameter wires, which keep the wires centered so the piercing screws have no trouble engaging the conductor. The upsidedown teardrop shape of the tubes also serves to keep the wires centered. Single Phase 120/240V 3Wire (2 hots, 1 neutral): In this configuration both hot wires pass through the body of the meter. The piercing screws are used to pierce the wire insulation to provide the meter with a voltage reference for each line. There is also a port on the meter for a neutral reference. The meter will function without this connection (at ~1% accuracy) but it will be 0.5% accurate with the neutral connection. Single Phase 120V or 208240V 2Wire (2 hots): As described above, the meter is designed to meter single phase electrical systems that dont have a neutral available. Both hot wires pass though the body of the meter and the piercing screws are used to pierce the wire insulation to provide voltage references to the meter. Single Phase 120V or 208240V 2Wire (1 hot, 1 neutral): In this case Line 1 passes though the tube marked L1. The piercing screw is used to pierce the wire insulation for L1 to provide the voltage reference to the meter. The Neutral reference can either pass through the Tube marked L2 or it can be connected to the port marked N. If the neutral passes though the L2 tube then the piercing screw is used to pierce the wire insulation for to provide the neutral reference to the meter. Fully solidstate kWh meter with 800 pulse per kWh pulse output. 0.51% accuracy dependent on setup (see above), LCD readout in hundredths of a kWh, to 99999.99 kWh. No conversion factor or multiplier.