Q: My question is what size wire is run between the current transformers and the MB 125 watt meter? I want to install the watt meter in the garage next to my breaker panels. I read the manual and it mentions using 8 gauge wire, but don't see why that would be necessary since a current transformer is used. by David Galliher from Florida on October 15, 2013
A: Thank you for your inquiry!
The MB125 is fitted with 20 AWG wires running from the current transformers to the meters themselves. Reliance Controls specifies an 8 AWG wiring requirement as this metering system is designed to monitor 50 amp loads. That 8 AWG wire would be the power conductor which is being metered, not the wires connected to the current transformer and meter.
It is important to understand that these current transformers are used for monitoring purposes and will not be transmitting any usable power. by Mike, Product Expert
Q: This post is old. Have you ever received an answer if the Reliance MB125 watt meter's donuts can fit over 6 awg wire? by Tom from Rhode Island on February 28, 2013
A: Yes, per the most recent QA I list that you can use #6 with this watt meter. It also says "if it will fit" which is meant as if you are using standard copper wiring. Some aluminum products have a larger diameter and will not fit.
by Mike, Product Expert
Q: The owner's manual states that you can not use wire over 8 AWG ? I have 6 AWG wire, will I still be able to use the Reliance MB125 watt meter?
by Michael Salonia from New Jersey on December 20, 2012
A: I have discussed this with Reliance Controls and they have said that you can use #6 as long as it fits in the coil (doughnut). They will be reviewing their installation instructions and will update when they get the opportunity.
by Mike, Product Expert
Q: Hi Jim, I have a 7200 watt running/9000 watt peak 120/240 volt generator. I want to monitor both 120 volt legs at the same time. I don’t need to monitor 240 volts at all. The reason for this is to balance the 2 poles. Got any suggestions? by Jay Danielson from Idaho on April 12, 2011
A: A wattage meter only monitors one leg per meter. with model MB125 you wire one leg to one meter and the other leg to the other so you can keep the load balanced. You can view the installation manual on the site under the specs tab.
Easy To Use (3) Durable (2) Reliable (1) Price (1) I'd Buy It Again (1)
Cons
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100% of respondents would recommend this product to a friend
9 Reviews
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Martin P. Saint Louis, MO
Purchased 10/7/16
2 Reviews
Most Helpful Positive Review
REVIEWED
NOV.
08
2016
Mb125 - Excellent 50-amp Wattage Meter
Works great!!! Highly recommend for any portable generator hook-up.
Pros:Durable, Features, Easy To Use, I'd Buy It Again
Martin Recommends This Reliance Controls Product
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10
Ronald S. Chico, CA
Purchased 2/17/17
3 Reviews
REVIEWED
MAY.
10
2017
Great Little Meter
Was what I ordered, Removed Panel indicators and mounted in the Hybrid Invert Wiring box instead of haveing another external box to wire in. Picked up the generator leads inside box. Good for visual indication of applied loads would use a digital power meter for real accuracy. Don't need that kind of accuracy for generator operation to support house loads in a power out situation or for battery charging thru hybrid inverter.
Pros:Easy To Use
Ronald Recommends This Reliance Controls Product
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00
Keith A. Glenville, NY
2 Reviews
REVIEWED
DEC.
07
2012
Wattage Meter Good But...
I received my wattage meter way ahead of the estimated delivery date of 1 1/2 months, and I was pleased at that. Overall I like the meter and its function- it works great.
My only issue, and it's minor but, the transformer leads are way too short for just about any installation. For example: next to my indoor/outdoor transfer switch enclosure. I used some extra probe cords from one of my hand-held electrical meter/tester that I had hanging around. They are somewhat flexible as the wattage meter leads are, and have the same rating for electrical wire.
I used some electrical stake-on connectors and extended the leads approx. 12 inches to allow for a neat and secured routing of the leads. I'm pleased that I can easily view the wattage of my system instead of pulling out my amp probe and figuring the wattage.
Note: I installed the transformers on the main feeding the breaker bars so I can monitor the utility or the generator wattage for better load distribution.
I received my wattage meter way ahead of the estimated delivery date of 1 1/2 months, and I was pleased at that. Overall I like the meter and its function- it works great.
My only issue, and it's minor but, the transformer leads are way too short for just about any installation. For example: next to my indoor/outdoor transfer switch enclosure. I used some extra probe cords from one of my hand-held electrical meter/tester that I had hanging around. They are somewhat flexible as the wattage... more
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50
George
Purchased 11/14/12
3 Reviews
10 Helpful Votes
REVIEWED
DEC.
06
2012
Prefer The Interlock Kit
I just received my Reliance Controls 50-amp watt meter, so I can't say how good it preforms yet. I am sure it will do its job.
I am installing this next to my main panel to monitor my portable generator, backfeeding my panel in the event of a power outage. Storms Irene and Sandy have prompted me to do this.
Each phase should be drawing the same amount of wattage, or as close as possible, for your generator to run as efficiently as it can. I also installed a generator interlock kit, which allows me to use as many breakers on my panel that my generator can support. This is where the watt meter comes in handy.
I prefer the interlock kit over a transfer switch which limits the amount of breakers you can use.
I just received my Reliance Controls 50-amp watt meter, so I can't say how good it preforms yet. I am sure it will do its job.
I am installing this next to my main panel to monitor my portable generator, backfeeding my panel in the event of a power outage. Storms Irene and Sandy have prompted me to do this.
Each phase should be drawing the same amount of wattage, or as close as possible, for your generator to run as efficiently as it can. I also installed a generator interlock kit,... more
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83
George Wallkill, NY
Purchased 11/4/10
2 Reviews
REVIEWED
NOV.
28
2010
My Review
The generator works fine. The cover don't fit on the cabinet. I called two of your service dealers
and had no help. I installed four draw down hasps to hold it in place.
The mb125 reliance control only one meter works. I called them and they said one ct must be
bad. they were going to send me a replacement ct. that was ten days ago and I havenot
recieved it. Overall I am not to happy with it.
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50
Jerry W. Irvington, AL
Purchased 2/28/15
REVIEWED
MAR.
22
2015
Mb125 Watt Meter
The meter works well as advertised.
That said, the input leads are entirely too short. My installation is through the wall and I had to splice extensions to get the length needed.
I did not pay close attention to the "Lower Limit" of the meter before I installed it.
The 50 Amp unit begins @ 1000 watts and the load I put on the generator doesn't register until a 240 unit kicks in like the water heater.
Jerry Recommends This Reliance Controls Product
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20
Cecil Columbus, OH
Purchased 10/31/12
2 Reviews
REVIEWED
JAN.
03
2013
Mr. Farmer
I had to use the generator, less thank two weeks after install for back-up for barn power. It worked just as i wanted!!!
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22
Bryan Annapolis, MD
2 Reviews
REVIEWED
NOV.
09
2012
Tells Me What I Need To Know
I had my electrician put the MB125 between my inlet box and my circuit breaker. I now know how much voltage I am using and it saves me from over-working my generator.
I think this is a must-have when connecting to your load center.
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55
Thomas W. Philadelphia, PA
Purchased 11/2/12
REVIEWED
JUL.
08
2014
Reliance Controls 50-amp Indoor Wattage Meter Review
Shop for the Reliance Controls 50-Amp Indoor Wattage Meter at Electric Generators Direct. Research Reliance Controls 815181010355 generator meters online. Find Reliance Controls MB125 generator meters & Reliance MB125 Wattage Meter features and specifications. Get the best deal; compare Reliance Controls MB125 prices now. Buy the MB125 direct and save.
Spec Sheet
