Power line communications interface and surge protector

1. A system comprising:

an AC power input port for connection to an AC power line;

an AC power output port for providing power from said AC power line;

an AC power surge suppression circuit for limiting voltage at said AC power output port;

a data port;

a capacitive data coupler for coupling a data signal between said AC power input port and said data port; and

a data port surge suppression circuit for limiting voltage at said data port.

2. The system of claim 1 ,

wherein said AC power line includes a plurality of power phase lines, and

wherein said AC power input port is for connection to said plurality of power phase lines.

3. The system of claim 2 , wherein said capacitive data coupler couples data signals between said data port and more than one of said plurality of power phase lines.

4. The system of claim 3 ,

wherein said capacitive data coupler couples a first data signal having a first phase to a first of said plurality of power phase lines, and

wherein said capacitive data coupler couples a second data signal having a second phase to a second of said plurality of power phase lines.

5. The system of claim 1 , further comprising an inductive choke that isolates said AC power surge suppression circuit from said AC power input port, wherein said inductive choke has high impedance at a frequency of said data signal.

6. The system of claim 5 , wherein said inductive choke comprises a plurality of chokes in series with said AC power input port.

7. The system of claim 5 , further comprising:

a fuse for protecting said AC power output port,

wherein said AC power surge suppression circuit comprises a low capacitance surge arrestor having (a) a first terminal connected to a terminal of said inductive choke closest to said AC power input port, and (b) a second terminal connected to a terminal of said inductive choke closest to said AC power output port.

8. The system of claim 5 , wherein said AC power surge suppression circuit comprises a surge arrestor connected in shunt across said inductive choke.

9. The system of claim 8 , wherein said surge arrestor comprises a gas tube arrestor.

10. The system of claim 1 , further comprising a low pass filter in series with said AC power output port.

11. The system of claim 1 , wherein said AC power surge suppression circuit comprises a surge arrestor connected between said AC power output port and an electrical ground.

12. The system of claim 1 , where said data port surge suppression circuit comprises a gas tube arrestor and an avalanche diode arrestor.

13. The system of claim 1 , further comprising:

a resistor that senses a voltage from said AC power input port;

a converter that converts said sensed voltage to a DC voltage, and

an optical isolator that receives said DC voltage, and provides an isolated signal to a logic output port.

14. The system of claim 1 , further comprising:

a first fuse having a first current rating, in series with said AC power input port; and

a second fuse having a second current rating, in series with said AC power output port,

wherein said first and second current ratings are different from one another.

15. The system of claim 1 ,

wherein said AC power input port is a first AC power port, and said AC power line is a first AC power line, and

wherein said system further comprises a second AC power input port for connection to a second AC power line.

16. The system of claim 15 ,

wherein said second AC power line includes a plurality of power phase lines, and

wherein said second AC power input port is for connection to said plurality of power phase lines.