Meters come in all shapes and sizes. Which is right for your environment?
By: Allan Evora
One of the questions we get asked a lot is, what meter makes sense to install for my particular application?
Well, it comes down to a few things.
- Is it a new construction installation or retrofit environment?
- Are you connecting to a building automation system or SCADA system?
- Do you need a local display?
Today I’m going to cover different meter form factors, especially in terms of considerations for ease of installation and future support.
Why the face?
Many manufacturers offer a meter without a display/face. This really eases the installation process, especially for retrofit environments. The majority of meters with displays require cutting a hole in a door or enclosure. In new construction, that’s not such a big problem. In a retrofit environment, cutting a hole can be a risky proposition. There are safety precautions. You have to be especially cautious of metal shavings interfering with potentially energized equipment.
In our experience, a meter face is beneficial for two reasons.
- Even though you connect to SCADA software or a network to read a meter, what happens when software malfunctions, or the network goes offline? Having a means to verify energy consumption locally is important.
- Integrators often don’t have a good means to verify the meter is working properly without a local display. Integrators unfamiliar with meters often require the OEM to come onsite to prove it’s functioning properly. Having a local display is a kind of insurance policy to show the meter is functioning and is installed properly.
Let’s take a look at different sizes and shapes of meters with both display and displayless functionality.
PowerScout 3037 meter
The PowerScout 3037 is a very simple meter we like to use on our installations. It’s a basic meter, which means it doesn’t do power quality, sag/swell, or transient detection. But if you need something to measure watt hours, loads, or current, it’s a good meter.
It has a pretty nontraditional meter shape. It’s meant to be panel-mounted in your equipment, and has provisions to be mounted on standard DIN rail. It’s got a built-in display, but the downside is that it has to be placed inside your equipment enclosure/panel.
The PowerScout 3037 meter also has remote connectivity and communications capabilities, which means it can be connected to an automation system. All-in-all, it’s a very cost effective, basic meter from a company that’s been producing meters for quite some time.
Shark 100 meter
The Shark 100 is a standard, panel mount meter made by Eaton. It’s pretty popular, and has been around for a while now. We use it in industrial applications and in some PV solar applications.
This meter has a traditional form factor, which means it’s got a quarter DIN configuration. Typically mounted in a panel or on a door, it has a built-in display that enables you to verify readings locally.
PowerLogic PM850 meter
This is a meter that has combined some of the features of the last two meters. It has a main body which contains all the electronics and metering capabilities, and a separate faceplate. The meter can be DIN rail mounted inside an enclosure, and has all the required connections for voltage, current, and serial or Ethernet network connections.
The nice thing about this meter is, it can be installed faceless, or you can add a remote faceplate.
These meters are capable of bringing 600 volts to the front door of an enclosure, which is viewed as a potential safety risk or hazard and often a violation of local safety codes. A remote display not only gives you a local means to verify the meter is functioning properly, it also allows you to avoid installing hazardous voltages on the door of the panel in which you’re working.
But there’s also another benefit. If you happen to have several meters installed in your facility, you aren’t forced to mount the display in the door. Rather than mount it, you can open the enclosure, connect to the display port, and view your readings locally on a case by case basis. You’d be using it as a tool or instrument to verify readings when having trouble reading them through your software.
GE PQM meter
This meter is one of the more reliable and popular GE meters. It’s called the GE PQM meter. One of the things you’ll notice right off the bat is that it has a nontraditional shape. It’s meant to be mounted on the door or on the front of an enclosure.
This meter has built-in power quality, and can support multiple communications channels.
Learn more about the GE PQM.
PowerLogic CM3250 meter
This is a higher end power quality meter made by Schneider Electric. It can be panel mounted in your equipment, or DIN rail mounted, which means you don’t have to cut any holes. This is another meter where the display can be mounted separately so you don’t have to bring hazardous voltage levels to your front door. It only requires a small hole to get the cable through and a few mounting holes in order to secure it to the front of your enclosure.
You don’t have to purchase a display with each meter. You can purchase one display, and when you want to read the readings locally, connect them using the supplied cable, and you’ll be able to read your readings and verify if your meter is functioning properly.
Veris E50 meter
This is an interesting meter. Compared to the previous meters, it’s got a very small form factor. Some people look at it and don’t realize it’s a meter. The E50 is one meter we’ve become very fond of for retrofit and multiple circuit situations. In a good-sized enclosure, you could probably fit up to a dozen of these.
In addition to the benefits of its size, it’s DIN rail mounted, and has a display. If you’re able to access the enclosure, you can read the display and verify the building automation system or SCADA system is in agreement with what the meter is reading. It’s a very convenient meter that comes from a reputable company.
PowerScout 24 meter
The PowerScout 24 is manufactured by Dent Instruments, and you can order it in a few different configurations. Inside the enclosure (you can order it with its own enclosure) are the brains of this meter.
This meter is called a multi-circuit meter, with eight elements labeled A-H. It can meter up to eight, 3-phase loads. Rather than installing eight separate meters, you can just install one PowerScout 24. Not only is its footprint extremely compact, it’s also very cost-effective. Whenever you have more than two metered loads in one area, this is almost always a better choice in terms of cost.
One of the tradeoffs with its size and capabilities is that it has no display. However, it does have a separate USB port, and the manufacturer provides free software. With your laptop and a USB cable, you could connect to this meter to verify readings. That’s not typically something an electrician or mechanic would do, so you need to take that into consideration when choosing this meter.
Learn more about the PowerScout 24.
Which meter is right? It totally depends on you.
There is a wealth of different solutions even beyond what I’ve shown you today. If we can help you specify or go through the process to see which meter makes sense for your environment, let us know.
Allan D. Evora is a leading expert in control systems integration and president of Affinity Energy with over 20 years of industry experience working in every capacity of the power automation project life cycle. With a background at Boeing Company and General Electric, Allan made the decision to establish Affinity Energy in 2002. Allan is an alumnus of Syracuse University with a B.S. in Aerospace Engineering, graduate of the NC State Energy Management program, and qualified as a Certified Measurement & Verification Professional (CMVP).
Throughout his career, Allan has demonstrated his passion for providing solutions. In 1990, he developed FIRST (Fast InfraRed Signature Technique), a preliminary design software tool used to rapidly assess rotary craft infrared signatures. In 2008, Allan was the driving force behind the development of Affinity Energy's Utilitrend; a commercially available, cloud-based utility resource trending, tracking, and reporting software.
Allan has been instrumental on large scale integration projects for utilities, universities, airports, financial institutions, medical campus utility plants, and manufacturing corporations, and has worked with SCADA systems since the early ‘90s. A passion for data acquisition, specialty networks, and custom software drives him to incorporate openness, simplicity, and integrity into every design in which he is involved.