---
product_id: 8024686
title: "Reliance ControlsMB125 Indoor 50-Amp Wattmeter Box"
brand: "reliance controls"
price: "AR$423261"
currency: ARS
in_stock: true
reviews_count: 8
url: https://www.desertcart.com.ar/products/8024686-reliance-controlsmb125-indoor-50-amp-wattmeter-box
store_origin: AR
region: Argentina
---

# 50A Power Rating Indoor Use 12,500W Max Reliance ControlsMB125 Indoor 50-Amp Wattmeter Box

**Brand:** reliance controls
**Price:** AR$423261
**Availability:** ✅ In Stock

## Summary

> ⚡ Power Up Your Space with Confidence!

## Quick Answers

- **What is this?** Reliance ControlsMB125 Indoor 50-Amp Wattmeter Box by reliance controls
- **How much does it cost?** AR$423261 with free shipping
- **Is it available?** Yes, in stock and ready to ship
- **Where can I buy it?** [www.desertcart.com.ar](https://www.desertcart.com.ar/products/8024686-reliance-controlsmb125-indoor-50-amp-wattmeter-box)

## Best For

- reliance controls enthusiasts

## Why This Product

- Trusted reliance controls brand quality
- Free international shipping included
- Worldwide delivery with tracking
- 15-day hassle-free returns

## Key Features

- • **Sleek Indoor Design:** Crafted for indoor use, blending functionality with a modern aesthetic.
- • **Maximize Your Output:** Handles up to 12,500 running watts, perfect for heavy-duty applications.
- • **Power Your Performance:** Designed for 125/250 VAC installations, ensuring optimal generator load balancing.
- • **Portable Power Monitoring:** Easily connect to your portable generator for real-time wattage tracking.
- • **Reliability Meets Efficiency:** Engineered for durability, ensuring consistent performance when you need it most.

## Overview

The Reliance Controls MB125 Indoor 50-Amp Wattmeter Box is a robust solution for monitoring generator loads in 125/250 VAC installations. With a maximum capacity of 12,500 running watts, this indoor unit is designed for seamless integration with portable generators, ensuring optimal performance and reliability.

## Description

Reliance ControlsMB125 Indoor 50-Amp Wattmeter Box

## Features

- Ideal for any 125/250 VAC installation where balancing the generator load is necessary for optimal performance
- For use with a portable generator to monitor the lead
- Made specifically for indoor use
- Maximum geneartor running watts: 12,500
- Mostly gray in color

## Images

![Reliance ControlsMB125 Indoor 50-Amp Wattmeter Box - Image 1](https://m.media-amazon.com/images/I/61xNTYUAerL.jpg)
![Reliance ControlsMB125 Indoor 50-Amp Wattmeter Box - Image 2](https://m.media-amazon.com/images/I/413w1GPK8jL.jpg)

## Customer Reviews

### ⭐⭐⭐⭐⭐ 5.0 out of 5 stars







  
  
    Well built, accurate wattmeter box that is easy to install.
  

*by U***9 on Reviewed in the United States on December 10, 2018*

Very well made, small box that does exactly what it is designed to do. I am using the 50amp box. There was no problem installing the current transformers over 6 gauge wires but the wires from the transformers to the meters in the box are pretty short! I installed it all myself in about 2 hours but could easily be done faster. I had to be somewhat creative with installing the box in-wall beside the flush mounted breaker panel and used a primed (unpainted yet) access door to conceal the box within the wall. I did an initial operational test using a 5500W heater and confirmed that the meters showed 5500W within the precision of the markings on the meter. Note that the precision of the 12.5kw (50amp version) is around 125W or half-way between each marking. I also used the PowerBACK (not completely installed yet) which works just fine. All parts were obtained on Amazon for a reasonable price.

### ⭐⭐⭐⭐ 4.0 out of 5 stars







  
  
    Purpose built, solid and enough room for 6 gauge wire.
  

*by R***Y on Reviewed in the United States on July 19, 2018*

A bit expensive for what it is BUT it's well built and serves a very important purpose. Reviews that suggest there is no room in the box to bring your generator wire into it, through the CTs and then into your panel/generator switch are wrong.  I used 6 gauge wire and had no real issues.  I brought the cable down through the top knockout and then out into the generator switch/main panel through the left knockout.  6 Gauge is not easy to work with as it is so I dont think the size of this meter added any add'l difficulty - just the standard difficulty in bending 6 gauge wire.

### ⭐⭐⭐⭐⭐ 5.0 out of 5 stars







  
  
    A winner!
  

*by S***E on Reviewed in the United States on August 30, 2014*

This unit is just the ticket to help manage electrical loads while using your generator or solar power system.  I used to use a clamp meter, measure the amps, multiply by the voltage and get Watts.  Now I read it right from the dual meters.It was easy to install, simply turn off the power, break the hot wire in the L1 and L2 sides of the breaker box, slide a current sensing transformer over each hot wire, reconnect them, turn the power back on and you're good to go.  It took me less than 20 minutes including punching out knockouts in both boxes.  So far, quite accurate as well.

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**Shop now:** [https://www.desertcart.com.ar/products/8024686-reliance-controlsmb125-indoor-50-amp-wattmeter-box](https://www.desertcart.com.ar/products/8024686-reliance-controlsmb125-indoor-50-amp-wattmeter-box)

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*Product available on Desertcart Argentina*
*Store origin: AR*
*Last updated: 2026-02-28*