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Posted

Group,

I have been sending Emails back and forth with the West Coast Rep. about the questionable mA readings of the new Sure-test analyzer when tripping the GFCIs. Here is his answer, with his permisson, of course:

"Our tester is listed to UL-943 for GFCI Testers and UL-1436 for Outlet

Testers which clearly define operational requirements for safety

verification. UL-943 states the tester must apply a 6-9mA leakage current

between hot and ground to simulate an imbalance between hot and neutral.

The tester does this using a 17.1 kilohm fixed resistor. The tester then

uses the line voltage which has a specification of 120VAC +/- 10% which

translates to 108VAC to 132VAC. Using Ohm's Law (E=I X R) or (I=R/E), at the minimum 108VAC/17.1 kilohms = 6mA, at the nominal 120VAC/17.1 kilohms = 7.5mA, and at the maximum 132VAC/17.1 kilohms = 9mA.

Note. To make this equation work exactly, the numbers are 120000 mV (millivolts) / 17100 ohms = 0.0075 amps. All parts of the equation must have the same resolution.

So, as you can see, the typical line voltage is 120VAC, and the tester applies

7.5mA. But, as the line voltage varies, Ohm's law will vary the actual trip current as the resistance creating the leakage current from hot to ground is a fixed value.

Rgds

Dave Kadonoff

Field Sales Engineer

Test & Measurement Division

IDEAL Industries"

I hope this answers all our questions.

Douglas? What say you.

Ron

Posted

Douglas,

Thanks for weighing in on this topic.

I'm just the messenger boy on this one, I'll leave the rest to others Waaay smarter than I.

I will pass your comments on by way of Email to Dave K. . I would give you his Email but he has asked me not to publish it for fear of an Email Deluge.

Thanks,

Ron

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