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Digital Line Monitor

(14 Reviews) Add A Review
Catalog Item # 24900
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Digitally monitor and meter all your AC power sources for your personal safety and appliance protection.
This compact, easy to use instrument is made with advanced microelectronics and provides accurate testing and monitoring of electrical outlets and systems. Constantly monitors voltage and frequency indicating potential improper polarity and ground wiring. Its small size and rugged construction allows for convenient installation in an electrical outlet or use as a portable service tool.

Voltage is measured as RMS which is much more precise than AC average. RMS metering is the only method that can accurately measure all AC power sources. The RMS voltage and frequency readings are ideal for monitoring modified sine waves such as solid-state generators, inverters and Uninterruptible Power Supply (UPS) products.

The Digital Monitor display will alternate between line voltage in RMS volts and line frequency in Hertz. The LCD display shows an "F" in front of the reading to denote frequency. Pressing the MODE button on the front of the Digital Monitor will cycle through the display modes. Both voltage and frequency are constantly monitored regardless of the display mode.

  • Fully tests incoming power for: Open ground, Reverse polarity, High/Low voltage
  • Three display modes available: Alternating voltage and frequency (VOLT/FREQ.), Voltage only (VOLTAGE),Frequency only (FREQUENCY)
  • Accurate testing and monitoring of all AC power source types
  • RMS voltage and frequency meter
  • Multi-tone fault alarm
  • Hands-free auto reset
  • Advanced microelectronics
  • One-button operation
  • Wiring diagnostics
  • LCD display with LED backlight
  • This item qualifies for Product Protection coverage! Protect Your Investment! Product Protection eliminates out-of-pocket expenses and protects against costly product repairs or replacement. We’ll cover 100% parts and labor for up to two years following the expiration of your manufacturer’s warranty. Warranty service is available at any Camping World location or at one of the 52,000 service centers across the U.S.

    Technical Specs

    Tech Specs

    Weight: Less than 1 lb.

    Manufacturer: Technology Research Corp

    Mfg Part #: AECM20020-012

    Tech Notes:

  • Voltage range 85 to 150 Vac RMS
  • Frequency range 40/80 Hz
  • Operating current 0.02 Amp
  • Under voltage alarm <102 Vac RMS
  • Over voltage alarm >135 Vac RMS
  • Under frequency alarm <55 Hz
  • Over frequency alarm >65 Hz
  • Outlet type 120V/15A single phase
  • Operating temperature range +32?F to +125?F

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    Digital Line Monitor: Customer Reviews

    Camper's Choice Rating

    (4 Based on 14 Reviews) Add A Review

    Reviewed by 14 customers


    Peace of Mind

    0 out of 0 people found this review helpful.
    November 20, 2013
    Haven't had a chance to use this monitor much. However, in a few months will hit the road in our fifth wheel. So far gives instant accurate readings. In the past had trouble with a few park's electrical line flow. Now I can check things out before a problem occurs.
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    Digital Line Monitor

    0 out of 0 people found this review helpful.
    November 20, 2013
    Works as specified. I have it plugged into the kitchen counter top outlet where it is easy to see. The line monitor could be improved by adding an LED back light so it can be monitored with the lights off. No other suggested improvements.
    Was this review helpful? Yes / No

    Excellant and must have product!

    0 out of 0 people found this review helpful.
    June 20, 2012
    Save your the self the headache of power surges before your setup site. We were assigned a slot at the campground, then we checked the power before hooking up. It was surging well over 160. Should be 120 for 50 AMP. We asked to be moved and rechecked new site. Campground had to send a tech out to fix the first one the next day. we could have had major damage done to our electical system This small device avoided major disaster for us. Recommend for new and older users alike. We keep it pluged in when camping to keep our power regulated and in check.
    Was this review helpful? Yes / No

    line monitor

    0 out of 0 people found this review helpful.
    June 14, 2012
    this one of the nice Monitor i got the frist night after i got this we stop at one of thoese big camp site we all know and when i when to hook up and before threw the swich the pedastole was bad save my but that day it just pay for it self save me alot of money
    Was this review helpful? Yes / No

    TRC Digital Line Monitor

    0 out of 0 people found this review helpful.
    June 05, 2012
    we wouldn't camp without this device...we keep it plugged in all the time in the kitchen... lets you know that the power to your unit is functioning properly...piece of mind...
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    A must have

    0 out of 0 people found this review helpful.
    July 04, 2011
    Unlike the other review, this does display the current reading... what is left! Use it all the time. This past week end the alarm sounded on it at a very busy campground which really saved our AC as the amps dropped to 100. I even let a friend use it and it detected a ground fault on his site, so this is a must have to monitor the electricity.
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    Digital Line Monitor

    0 out of 0 people found this review helpful.
    January 20, 2010
    I totally agree with the two other reviews. I think this little monitor should be a must on any RV. It is so nice to know if I am getting enough ' juice ' before I plug in my Roadtrek and before I use any of the appliances. When I have been where there was a problem the campgrounds have fixed the problem or moved me to another site. I have recommended this to others and would purchase it again though I hope this one lasts a long time. I have already had the monitor for five years or so.
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    Works Great!

    0 out of 0 people found this review helpful.
    August 24, 2009
    This is a super handy power monitor device that has identified several problems before they became bigger problems. I especially like the over/under voltage audible alarm. Identifies potentially dangerous problems like reverse polarity, no ground or neutral. Only negative is you have to be close to the unit to read the display. Very good value.
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    Worth the Price

    0 out of 0 people found this review helpful.
    April 06, 2009
    So far, this monitor has identifed several low voltage conditions in various campgrounds, has identified a pedistal that had lost its ground, and has identifed that one of the extension cords that I was using had lost its ground. All of these are potentially dangerous conditions. The display is large enough and clear enough, but quite frankly I wonder if I would have noticed that there was a serious problem without the built-in alarm that went off each time. There are lower priced monitors, but none of them have the features that this one has. It is well worth the price.
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    37 out of 46 people found this review helpful.
    July 07, 2008
    I bought one 2 years ago. I like it because it will tell me my generator volts & cycles. It also lets me know if park power is correct.It beeps when there is low voltage so we can turn off unneeded 110 volt items. I also sometimes loan it to friends so they can check their generators. We leave it plugged in ,in the kitchen.
    Was this review helpful? Yes / No

    Digital AC Monitor

    193 out of 325 people found this review helpful.
    December 12, 2005
    This is a MUST have item if you have any electrical stuff thats inportant to you. I have one in my Class A and one in my Class C. They are excellent to have operating whether you are running a generator or plugged into shore power. Let you know if your voltage drops. I highly RECOMMEND this unit. This small investment reaps big rewards in savings.
    Was this review helpful? Yes / No

    Lets you know what you need to know

    132 out of 214 people found this review helpful.
    July 25, 2005
    The temperature was over 102 degrees. With the AC running, the breakers blew as soon as my wife turned the microwave on while she blow-dried her hair. I did not have time to stop her. With fear in her eyes at the rising temperature, I had to explain everything would be okay, but honey this is not like a motel. The breaker reset in the airstream was easy, but took me a while to remember that there were breakers on the pedestal outside. I was beginning to worry myself. Then I looked at what numbers were reading on this device. The neat thing about this product was that there were about 10 less volts at the Park, running at about 116, than there is when hooked up at home, which runs at 126. This told me I was getting less juice than when parked at home. The morning we were leaving as I was getting us ready to leave the alarm on the device went off, looking at the numbers, we were down 10 more volts short. I believe there were twice as many campers as the day before when the breakers blew parked at the campground. I am not an electrician. This device tells you if there is a problem. It works and there really is a need to know.
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    120 Volt meter

    198 out of 206 people found this review helpful.
    May 18, 2004
    This voltmeter can tell you a lot. If it reads below 105 VAC then shut off your air conditioner. If the voltage climbs by more than 5 VAC when the compressor cycles off, there is a problem with your generator voltage regulator, or if you are plugged in, the receptical you are plugged into is worn out - the clips inside of it are not holding tightly to your RV cord. This will cause the cord to overheat, and low voltage is bad for your air conditioner compressor. If you are below 105 VAC even with the air conditioner off, you need to increase the voltage before re-starting the air conditioner. When running on the generator, check the Hertz. If it is not 60, + or - 1 HZ, then have the generator checked out. You can read my posts on RV.Net Golden HVAC
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    Visual piece of mind

    195 out of 202 people found this review helpful.
    October 10, 2003
    This little guy constantly monitors incoming power and alerts you to high or low voltage conditions as well as incorrect line frequency. It will also alarm if the wiring is miswired (reversed polarity) or no ground line is present. I leave one plugged in whenever we're camped and a quick glance at the display lets me know if how much line voltage we've got in the camper. More piece of mind.
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    Q & A

    Product Question & Answer

    2 questions : 2 answers
    Expand All
    Will the unit shut off electrical appliance if alarm goes off?
    1 answer(s)
    Can this unit stay plugged in all the time?
    1 answer(s)

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