What is the best way of connecting LEM LAH 100-P to power lines. enter image description here The power cable will have 50 to 60 amps. I am working with 4 gauge AWG wire. What are the connectors designed for? What kind of PCB or other medium could be best. We are prototyping now so how to best connect the wires? Is the only solution a lot of solder?

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    \$\begingroup\$ Multilayer PCB with thick copper, a PCB terminal connector for high current. Or maybe you buy a LEM with a window, so you pass the wire through. \$\endgroup\$ – Marko Buršič Feb 15 '18 at 21:28
  • \$\begingroup\$ Clearly you are new at this, in terms of dealing with high currents. We can offer suggestions and 'DO-NOT-DO-THIS' type of answers only. We cannot design it for you, as we do not know what all the variables are. Also, the manufacture specifies that an enclosure is mandatory. \$\endgroup\$ – user105652 Feb 15 '18 at 22:34
  • \$\begingroup\$ Your advice is appreciated. They must make the sensor for some some to use. I would not do anything unduly unsafe. \$\endgroup\$ – rur2641 Feb 15 '18 at 22:46
  • \$\begingroup\$ If you do not want to make a PCB, pick one of their other products, one that is panel mount, or one with a "window" to pass the high current wire through: lem.com/hq/en/content/view/269/206 \$\endgroup\$ – τεκ Feb 16 '18 at 2:15

First of all elongate the PCB so the low voltage parts are away from the high-voltage side. Double-sided PCB with 2/2 oz copper pour, 90 mils thk, with thick tin/lead solder plating out each side of the 3 fat pins to a 1/4"/7mm hole.

You can use a crimp on ring terminal but with 4 awg THHN you may want to bolt in a set-screw lug for 4 awg wire. Use a 1/4-20 SS bolt or a metric equivalent.

4 awg is so stif it is better to let this assembly 'float' where the wire wants it to, and have a small gauge (22-26awg) multi-wire cable come from this enclosed assembly to its destination. The device outputs 50 mA with a 100 amp RMS input, hence the 1:2000 scale.

Slot cut the PCB .031" by 1.0" between the high voltage and low voltage sides to prevent creapage due to moisture and/or dust.

Use a 200 ohm 1% or .1 % load resistor to scale it as a voltage so that 100 amps AC equals 10 VAC output (+/-16 VDC), or 20 ohms to equal 1 VAC output, or +/- 1.6 VDC if DC input.

  • \$\begingroup\$ Thanks for the great advice. The project is not going to develop a PCB. I was hoping for a solution that uses a piece similar to a bus bar, then solder the cables further away. I should have picked appropriate parts like a Hall sensor. \$\endgroup\$ – rur2641 Feb 15 '18 at 23:45
  • \$\begingroup\$ What do you mean by multi-wire cable? A google search for multi-wire cable returns multi-conductor cable. If the max amperage for 22 awg is under 1 A, will it require over 60 cables? \$\endgroup\$ – rur2641 Feb 16 '18 at 2:33
  • \$\begingroup\$ I was referring to the 3 pins that are the output of the Hall sensor. The current consumed is less than 100 mA. It outputs 0 to 50 mA depending on the mains current. You only need 3 small awg wires. +12 volts, -12 volts, and output. \$\endgroup\$ – user105652 Feb 16 '18 at 2:38

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