High Voltage Reading on Brand New Receptacle I put in. Normal?

Question

I just put in a brand new 15amp outlet receptacle. It's on a 20amp circuit, so I used 12/2 wiring. I tapped into another 15amp receptacle for power.

I have a voltage detector that just measure High/Low voltage. It does not give me the actual numbers. It's kind of like the bars on your cell phone service or wifi. More bars, higher voltage.

Normally, when I plug the voltage detector into the existing receptacles that came with the house, I get a really low reading.

When I plug it into the new one (I purchased a cheap Eaton one from Lowes for like $0.80), it shows high voltage.

When I look into the receptacle, the ones that came with the house look like they have black tabs inside the outlet, almost like a safety feature if someone sticks there finger in there or something. It also "clicks" when you plug something in.

The Eaton one I got does not have that. No tab, just open plug that slides right in.

Here is my voltage readings New/High Voltage. Old/Low Voltage.

I will add- no matter what, when I put the voltage detector on the hot wire, it goes full red like the New Eaton picture.

My question is, is it normal that two different receptacles may display different voltage like this?

My theory is the existing ones have the metal contacts within the receptacle farther back than the Eaton one I purchased. My voltage detector probably would go full red on the old ones if I could stick it in farther.

Plug works fine. No issues. Just hadn't seen this before and figured I'd ask.

Answer 1

It sounds like you did not force your non-contact voltage tester past the gate of tamper resistant receptacles*. So probably you did not damage them.

This gate would prevent insertion of the probe and would probably lead to a "low voltage" message. If you would plug in an extension cord which does not have a tamper resistant other end and fully insert your tester into the hot slot on the extension cord, you will probably find the low voltage message gone.

EDIT

*The receptacles with black inside are probably "tamper resistant" and the ones you got are not. A tamper resistant receptacle has a mechanical gate which only opens if blades are inserted simultaneously into both the hot and the neutral slots.

The modern code requires tamper resistant in many places to prevent toddlers from getting electrocuted when they get the idea to try to poke a hairpin into the hot slot. You should not try to force your detector into the hot slot of a tamper resistant receptacle; you could damage it.

Answer 2

These sort of testers are very hard to interpret properly. If you want to do any electrical work, you need a DMM (Digital Multi Meter) of decent quality. Yes, they cost a few bucks ($30-$50 or more for high end professional versions), but geeze, it's a pretty small investment. Product recommendations are OT here, but Fluke is a great brand, Klein is OK too. OK, I'll shut up with any semblance of product recommendations now, just don't get the cheapest meter at HD or harbor freight.

Outlets are dead simple to inistall and unless it's a multi wire branch circuit (MWBC), it's almost impossible to wire it incorrectly: Black wires to brass screws, White wires to silver screws and ground to the green screw.

It's common to have significant voltage variations...Like down to 115 volts or up to say 123. My home normally runs at a little over 120 for convenience outlets and it's not a problem.

If you are really concerned about this, get a decent DMM, turn off the power for that circuit, pull the outlet out, turn the power on and carefully measure from the brass and the silver screws. Even if it's up to 125, you don't have a problem.

With the heatwave going on right now in the west (I DK where you are), I wouldn't be surprised if power levels dropped to the 115v range.