I had a service call today. Here is what happened. The ladies washer stopped working. I put a meter on the receptacle and got 118 volts, line to neutral. And line to ground, same thing. So the power was there right? Plug in washer, nothing! However when I plug the washer in any other receptacle, it worked! I was thinking, bad neutral?

This is a dedicated separate line. Down to the panel, check power at washer breaker with meter...same reading 118 Volts.

Anyways, to make a long story short. It was a faulty breaker. It was letting the voltage through but not the amps. My meter would read it, yet nothing plugged in would work.

Does this make sense? I have never come across this before.

Makes sense to me. If you had measured the voltage with a load it would have been zero or at least lower. Ohms law applies. Zero amps = zero voltage drop.

You might want to look at this
https://www.electrical-contractor.net/ubb/Forum1/HTML/002313.html

I just saw a demo this week of an Ideal circuit analyzer that puts a 15-20 amp load on the circuit being tested. Should eliminate the "phantom voltage" problem. I believe it was model 61-156. Try this link: http://www.idealindustries.com/tm/SureTest.nsf

Did replacing the breaker fix the problem? I have come across recptacles that were simply worn out from years of plugging and unplugging. In other words, the test leads of my wiggy would read voltage but the blades of the plug would not make adequate contact.

I have always wished that my meter had a button I could press to put a small load on the circuit to get rid of those phantom readings. Just a resistor across the meter would do it but I've never bothered to actually make anything that would work.

Kale,
Any idea of the cost of the this tester?I like the looks and concept of it.

When I explain to my students why I believe analog meters are superior to digital, they laugh at me.
I'll bet that I will make less mistakes trouble-shooting with an analog meter.

Any takers?

Ed

Spyder....

When trouble shooting, I removed the receptacle and replaced with a new one to no avail. Indeed, it was a faulty breaker. It was replaced and all works well now.

I really enjoy trouble shooting, and I thought I had seen it all but never came across 'phantom voltage'. Now I have to remember that when trouble shooting, I need to apply loads to my testings.

We use a tester, that we can plug into a meter socket that applies 25amps of load to a phase and neutral. The unit uses a toggle switch to allow us to test both phases one at a time. The unit is basically has two hair dryers in it and two panel voltmers meters to indicate the affect of applying the load & pick up points to allow you to use a handheld voltmeter to check the voltage. The units we use are made by Arnett Industries:

http://www.arnettindustries.com/products/supbeast/supbeast.htm

I think the above unit is great for utility work, where we test at the meter socket, but for checking outlets, why not use a 1200 watt hair dryer. You could plug it in to the outlet in question, or make an adaptor with insulated alligator clips for checking breakers or connections.



[This message has been edited by ameterguy (edited 01-18-2003).]

When i was a refrigeration mechanic i would see this on 24v thermostats about once every 10 years,just long enough to forget about it.I would replace a prefectly good contactor in the condenser only to find the thermostat was passing full voltage but no current.

I had to post some stuff regarding those misnomers of “phantom voltage” and “residual currents” on https://www.electrical-contractor.net/ubb/Forum1/HTML/002313.html

The instrument kale posted “Ideal #61-156 is a fine instrument. It costs over $300. There are several models but I would recommend at least the 61-151 model which included ground impedance tests as well as what Ideal calls “false ground” (actually a “boot leg” connection) Our OSHA inspectors use it (among others). Although the ability of the instrument to load the circuit in order to test or measure the voltage drop on the branch (more important for diagnostics for qualified electrical professionals) We (OSHA) use it for other tests. Primarily the equipment ground impedance test to insure that impedance of the equipment grounding conductor is sufficiently low enough to !. Limit the voltage to ground and provide a LOW IMPEDANCE path which will facilitate the operation of the circuit protective device (over current / breaker / fuse). From the NEC obviously. In an accident / incident / fatality investigation one has to establish many causal factors including that an enclosure could / could not become energized and the only way to establish that is to test / verify it’s ground path / effectiveness / impedance.

OSHA electrical standards courses also have students (including OSHA investigators / inspectors) testing the ground impedance on branch circuits tho establish that it’s low enough.
1.2 ohms maximum for a 20a branch, 1.6 ohms maximum for a 15a branch, and .8 ohms maximum for a 30a branch etc.

The other nice test provided by the Ideal instrument is what they call the “false ground” test. That’s the test for a “boot leg” or neutral to ground connection in the branch and as you know that connection can only be at the main service disconnect (main panel).

There is another instrument which performs the same tests as the Ideal tester. That is the Inspector II manufactured by Tasco in the Denver / Colorado Springs area. See the instrument at http://www.professionalequipment.com/xq/ASP/ProductID.65/id.5/subID.57/qx/default.htm

OSHA doesn’t endorse products but do suggest numerous (as many as we know about) hazard abatement options.

I use and train students on both these instruments.
Although these instruments are in the $300 range you could get the best pricing at
habitat for safety.com
or call them at (440) 286-5502. Tell them OSHA Professor Grizzy suggested you call and they will do right by you, and NO I don’t have any interests in this company or any of the companies or products. I’m just trying to find the best pricing for the best equipment to keep professionals safe out there.

Remember, once were beyond plugging an instrument into an outlet and are alligator clipping diagnostic equipment into circuitry we now need appropriate PPE (there that nasty word again) as prescribed in NFPA 70E, for not only electrocution protection but also burn protection for arc flash / arc blast and don’t forget eye protection.

OSHA Professor - Grizzy

A good ol' fashioned wiggy will usually find this one 9 out of 10 times, at a much cheaper price than a load tester. Just a thought...

ameterguy,

Any idea what that tester costs?

Redsy,

The cost of the combo package is approx $800.

We have found that we can detect a weak or failing service tap using these devices.