Sunday, September 26, 2021

MENU

RV Electricity – Just Ask Mike (J.A.M.): Combination voltage and 3-light tester

By Mike Sokol

Welcome to my J.A.M. (Just Ask Mike) Session, a weekly column where I answer your basic electrical questions. If you’re a newbie who’s never plugged in a shore power cord (or ask – what’s a shore power cord?), or wonder why your daughter’s hair dryer keeps tripping the circuit breaker, this column is for you. Send your questions to Mike Sokol at mike (at) noshockzone.org with the subject line – JAM.


Dear Mike,
I have one of the voltage testers you’ve previously recommended and it works great plugged into an outlet inside of my RV as a quick reminder of the voltage, as well as being a pretty nifty night light. But I also carry around a 3-light tester for basic outlet checking. Is there anything small and economical you can recommend that does both? —Doug

Dear Doug,
Yes, I do have a new test product that I like that functions both as a 3-light tester, as well as being a plug-in digital voltage tester. And since this one was originally designed for testing European power (240 volts), it should be just fine if it accidentally tangles with a miswired 30-amp outlet (while using an appropriate dog-bone adapter, of course).

I found this nifty tester online a few months ago and have been using it in a variety of voltage checking situations – and it looks really solid so far. Named the HT106B Socket Tester Pro from Kaiweets, it performs all of the 3-light tests for outlet polarity, open ground, open neutral, etc., as well as being a 3-digit digital voltage indicator.

In addition, it performs a standard 5 mA GFCI safety test – which you should be performing on all of your GFCI outlets once a month (or at least once a camping season). I’m showing it plugged in next to a standard 3-light outlet tester on my bench for size comparison. While it’s not something you’ll want to carry around in your pocket, this gadget is certainly a reasonable size when compared to a traditional digital meter.

Its only real drawback that I can find is that the ground pin is designed for an outlet oriented in traditional “ground-down” configuration. And as we all know, receptacles (outlets) on campground pedestals are required to be mounted with a “ground-up” configuration. So you may need to stand on your head to read the voltage numbers, or just use a short (1 ft.) extension cord which allows you to reorient the display.

Also, for quick voltage and polarity testing of the 30-amp outlet on a campsite pedestal I use one of these 30-amp to 15-amp dog-bone adapters in my RVelectricity seminars and it works great.

Where to get one? Well, as usual you can purchase it HERE on Amazon, and possibly from a few more places if you look around. However, I’ve not seen it in any of the standard big-box stores we all know and love (Big Blue and Big Orange). If you know of other places to get it locally please let me know in the comments below and I’ll update the post.

OK, everyone. Remember that electricity is a useful and powerful force, so we all need to pay attention to safety precautions while using it.

Let’s play safe out there….

 

Mike Sokol is an electrical and professional sound expert with 50+ years in the industry. His excellent book RV Electrical Safety is available at Amazon.com.

##RVDT1277;##RVT936

Comments

Subscribe
Notify of

This site uses Akismet to reduce spam. Learn how your comment data is processed.

35 Comments
Newest
Oldest
Inline Feedbacks
View all comments
Bob J
6 months ago

Wow…Amazon not shipping this until first week of April. Hot item!

Ross Boyer
1 year ago

I bought one of these testers and found with my Simpson, Fluke and Lowes meters that reading is 6 volts low.

Steve A Mangrum
1 year ago

Mike,
Regarding the HT106B Socket Tester Pro from Kaiweets you stated, “Also, for quick voltage and polarity testing of the 30-amp outlet on a campsite pedestal I use one of these 30-amp to 15-amp dog-bone adapters in my RVelectricity seminars and it works great.” So, if this does not apply to a 50-amp service is there a similar product that would?

Dave
1 year ago

I bought the HT106B Socket Tester Pro based upon the recommendation and really like it. I leave it plugged in to watch the voltage in the RV. The only issue is it takes up a whole outlet due to it’s size. Maybe the next model will move the plug higher or lower to free up the second outlet.

Joel L
1 year ago

I have a progressive industries EMS-PT30 surge protector. It seems to test for all the things this Kaiweets tester does except the GFCI. Do I really need this tester also?

Bob Bullock
1 year ago

Mike, I bought the Kaiweets tester you recommended, and found it to be off by 10 volts (read 115V vs. 125V actual, as measured by a Klein and a Fluke meter). I wasn’t expecting much, and I realize products aren’t always perfect, but just thought you might want to gather some more data on this model.
Thanks

Steve S.
1 year ago

TTU (Two Thumbs UP) on this combo unit Mike!
Years ago when we started camping we bought a 3 light tester and plug-in voltmeter. Because . . . that’s what was available and cheap. Every time we go camping, the first thing we do before plugging the rig into the pedestal is plug the dogbone (like the one pictured above), and a 3 light tester to verify proper wiring. We then unplug the 3 light tester and plug in the voltmeter to confirm proper voltage. In all these years, I never thought to check for new gadgets. How nice to have a single device that does both jobs! I know its a minor inconvenience, but they all add up. One less item in the electrical toy box, and one less thing to have to remember to do when hooking up. It all adds up.

Roy Beals
1 year ago

HI, I am Roy at flagman@wi.rr.com . I have a Surge Guard model 34951 portable surge guard. I lost power in my 2011 Monaco Cayman , but only for a short time . I checked the surge protector and it read 119V on one leg and 120v on the other it read 60 amp .But it read only 3a on the 119v leg and no amps on the other. I read a message “NO BLE” and under, it read “peers”. Do I need to worry about anything ? Please reply by email or by phone at 2622208024 .I would be grateful for any help, Roy…

Mike Sokol
1 year ago
Reply to  Roy Beals

I just got back from 4 days in California teaching music mixing theory (my main job) but I’ll think on your problem in a day or so.

RW BAKER
1 year ago
Reply to  Roy Beals

No BLE means it doesn’t have bluetooth.
. . No worries.

tom
1 year ago

Mike, Thanks for the tip on this tester. After your extremely fine talks at RVillage Rally in Florida, I ordered one when I got home. What a great idea!

Steve Barnes, Kamloops, BC
1 year ago

Mike, I just replaced my 4 6 volt Interstates. I got 10 years x 5 months/year service out of them.
I want to monitor my new ones. I want a meter for permanent mounting in my 5th showing percentage charge, not just voltage. My objective is to never use them if falling below 50%. Does this exist?

Mike Sokol
1 year ago

I’ve found a few of them lately that will work with flooded lead-acid and AGM batteries, but not for Lithium batteries. https://amzn.to/39K7Aad

Don Barylski, Winnipeg
1 year ago

Hi Steve – I have a meter called a tri metric from bogart engineering and it does exactly what you want

Wolfe
4 months ago

As you know if you watch voltages, the voltage under load is not an indicator of SoC… you need to count joules (or at least mWsec) …and track against expected capacity, preferably calibrated against Peukert corrections. I made a meter that does that (and much more analysis) but it wasn’t a simple task.

Brian
2 months ago

You need a shunt based battery monitor in order to get an accurate reading while in use and while charging. There are many to choose from but Victron is among the best.
Wow just noticed this question is a year old, must be re-running old articles?

Last edited 2 months ago by Brian
Brian
2 months ago
Reply to  Mike Sokol

Thanks Mike, now that I have everyone’s attention I want to bring up an issue with the inexpensive 3 light testers. These testers use neon or LED lights which will glow with the tiniest amount of current, and in an open ground situation it may still test normally with the 3 light tester although the ground light may be a bit dimmer. Applying a load such as a “Wiggy” tester will expose this and the glowing lamp will extinguish as soon as the load is applied. I had this experience very recently at a park, my EMS said open ground but the 3 light tester said all was good. Dug out my Knopp solenoid tester and sure enough there was no ground. The 3 light tester showed good inside the rig but the ground light was noticeably dimmer, and the GFCI test button failed to trip the GFCI because as you know those testers use the grounding path to simulate a fault.
My suspicion is that the pedestal had the grounding wire attached to the floating neutral bus and the receptacle was only bonded to the enclosure leaving no continuity to complete the grounding path.
I do know that if you take a 2 wire neon tester and test from hot to the concrete of a structure the lamp will glow, so I suspect there was a tiny bit of current flow to earth from the EMT (yikes) they had used for the wiring which was enough to light the lamp on the tester. If they relied on the EMT as the grounding path you know how that works underground after a year or two! The fact that EMT was used underground told me right away it was an amateur installation.
As a retired electrical contractor I offered to take a look at it at no charge but was treated with hostility and denial that any problem existed.
So the main point of my post is to show how the inexpensive 3 light testers are not always truthful and your best defense is a real EMS that constantly monitors for power issues. In a recent 10 day trip it identified problems at 2 different parks, one was voltage down to 98V when adjacent AC units ran. You wouldn’t know this without constant monitoring, just because it’s at 120 when you arrive doesn’t mean it will stay there.

Last edited 2 months ago by Brian
Admin
RV Staff (@rvstaff)
2 months ago
Reply to  Brian

Hi, Brian. That previous article about the voltage and 3-light tester was linked in an ad for that product. It just stands to reason, then, that the article was published, and comments were received, at an earlier time. Have a great day! 🙂 –Diane

Wolfe
1 year ago

If you want to see a very NOT pocket size but true all in one tester, check out my gonzo prototype… 😀

https://youtu.be/QXJ0mMiWBMo

Determination is the mother of really ugly engineering!

Glenn
1 year ago
Reply to  Wolfe

Interesting! Wonder what Mike’s thoughts are on your prototype. Good luck with it.

Wolfe
4 months ago
Reply to  Glenn

Just to continue the electronic insanity, i built it into a gutted TT30 adapter and added an OLED display. Yes, I know I glued in the OLED crooked!

https://youtu.be/FLoonQAq-aw

Eddie Harris
1 year ago

Hello Mike, is there a gadget like this for 50amp receptacles? We have the volt tester but this would help.

Gene Cheatham
1 year ago
Reply to  Eddie Harris

I was just going to ask if it would work if using a 20A to 50A plug adapter to check voltage on the 50A socket too, if it has that voltage range. Will be interesting to see what Mike has to say.

Wolfe
1 year ago
Reply to  Gene Cheatham

As is, that only checks one 120V leg. You’d need to mirror the function into the other leg for 50A plugs.

Mike Sokol
1 year ago
Reply to  Wolfe

You just need a 50-amp male to double 15-amp female Y cable for testing. I can’t recommend that adapter cable for powering anything due to the overload possibilities, but it works great for testing.

Mike Sokol
1 year ago
Reply to  Eddie Harris

Not currently, but I’ve heard a rumor about a manufacturer getting ready to make one. However, I’m under NDA with them and can’t discuss it just yet.

Wolfe
1 year ago
Reply to  Eddie Harris

You would just need a sort of splitter to connect two of these $7 devices on opposing legs of your 50A plug. It is trivial to custom wire that yourself if you know how. If you’re mildly into electronics/circuitry, its almost as trivial to make the whole 3 light/voltage tester yourself in one unit. The tricky thing missing either way is detecting energized ground/hot skin like I do above and apparently(?) Mike intends to do eventually…

Drew
1 year ago
Reply to  Wolfe

Just get a v.o.m.- it does many things. RV’ers should carry one as a basic tool.

Karin S.
1 year ago

Hello Mike,

Since you did not mention the reverse polarity neutral gruond issue, may I assume this gadget does NOT test for it either? And that we will still need our non contact voltage testers to make sure our RV’s are not “charged?”

Drew
1 year ago
Reply to  Karin S.

Karin,
Click on the tester- you’ll see all the functions….

Wolfe
1 year ago
Reply to  Karin S.

You are correct… this tester does not detect an “energized ground” – the cause of what you know as “hot skin.” Still use a NC tester.

Mike Sokol
1 year ago
Reply to  Karin S.

Karin,
Currently there are NO devices on the market that will automatically test for a Reverse Polarity Bootleg Ground (RPBG). You still have to use a NCVT (Non-Contact Voltage Tester) or a Digital Meter between the RV chassis/skin and a short ground rod to confirm that you don’t have an elevated skin voltage. I’ve shown a prototype RPBG tester to a number of aftermarket manufacturers, but no traction so far.

However, since it appears that the NFPA committees are now reading my RVelectricity and No~Shock~Zone articles and using them to create new electrical code (without telling me first, of course) perhaps manufacturers will respond to me publishing more articles about this issue. We shall see….

Wolfe
1 year ago
Reply to  Mike Sokol

Actually, there are many devices on the market that detect energized ground. I used to have 3lite+EG, this featured device is 3lite+V, so only the 3+EG+V trinity is rare. I’m not under NDA against myself, so maybe I’ll release my device miniaturized from the monster above, plus natural language OLED… 😉

Btw, in the mean time, duct tape an unpowered $1 LCD EG detector to this device and have all three for $8… just remember to look at the EG before touching the box to plug in the 3lite.

Wolfe
4 months ago
Reply to  Wolfe

The good news is, i built the thing in a very reasonable package… so, “it exists.”

The bad news is, manufacturing this isn’t my day job, and as Mike pointed out I shouldnt invite people to casually play with line power by explaining how i did it if they don’t know. Lawyers ruin everything!

Follow us!

31,714FansLike
26,462FollowersFollow
66,000SubscribersSubscribe