Am I reading this voltage tester wrong?

Thread Starter

Shawn333

Joined Oct 26, 2018
2
I bought this cheap voltage and continuity tester, Reed ST-9902N

I'm trying to get the votages of the breakers in a subpanel, and all I am getting is 12v for one leg, and than 24v for the next.

I'm pretty much a big newb at this. If I test the black and red wires that the power comes into the panel, they too only give me 24v

+VDC

VAC

12 and

24

I should be getting 120v and 240v???
 

Reloadron

Joined Jan 15, 2015
4,918
A US breaker panel, for example a mains power entry you should be seeing 240 VAC between the Black and Red lines. Either Black or Red to the White should be 120 VAC (all plus or minus a few volts). You should have two columns of breakers which alternate 120 Volts to the common White line.

REED ST-9902N Voltage/Continuity Tester

Features



    • Automatically selects AC voltage, DC voltage or continuity
    • Visual (seven LEDs) and audible (buzzer) continuity indications
    • Non-contact AC voltage detection
    • Automatically turns on and off
    • UL approved
    • Polarity indication
    • Cat. III, 600V safety rating

I will also add unless you are comfortable working in a breaker panel and understand the incoming voltage and how it is distributed you may want to back out before something really bad happens.

Yes, you should be seeing 120 & 240 VAC depending on between which two points you measure. I see where the tester you are using is discontinued and yours could be faulty, that is my guess.

<EDIT> You would likely do better to go to any home improvement store like Lowes or Home Depot and buy a cheap (inexpensive) multi-meter.

Ron
 
Last edited:

spinnaker

Joined Oct 29, 2009
7,837
I bought this cheap voltage and continuity tester, Reed ST-9902N

I'm trying to get the votages of the breakers in a subpanel, and all I am getting is 12v for one leg, and than 24v for the next.

I'm pretty much a big newb at this. If I test the black and red wires that the power comes into the panel, they too only give me 24v

+VDC

VAC

12 and

24

I should be getting 120v and 240v???

A newb shouldn't be sticking their hands into a breaker panel without an experienced person standing by. Touch the wrong thing and they might be reading zero volts on you.
 

Thread Starter

Shawn333

Joined Oct 26, 2018
2
Thank you for your replies, I tried the meter somewhere else and it works. I think the fuse from the main is blown. Anyhow, no-more messing around with it, you guys are right it is dangerous.
 
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