Virtjoule

BAS

Jul

Announcing Virtjoule Juice – World’s first dedicated cellular CT

Posted by randy at 9:10 am

Summary

Virtjoule has been in production and in the field with a new Cellular CT device called Virtjoule Juice. It’s a new continuous monitoring system for amperage readings used on any type of equipment electric motors or other types alternating current draw.

The new Virtjoule Cellular CT has been calibrated with the Magnelab SCT-0750 line of industrial current transducers (CT) making it both accurate and flexible for reading amperages from 0 to 3,000 amps.

With the Virtjoule Cellular CT sensor and monitoring service, you can find problems such as short or long cycles, over or under amperage conditions, and after hours operations, all of which may indicate operational problems which should be corrected before becoming expensive repairs, large utility bills, or interrupting critical business processes.

Monitor Amperage and Power

Current transducers are a special type of sensor that can not only tell if current is flowing through an alternating current wire, it can also tell you how much amperage is flowing through the wire which is useful for both fault detection and energy studies.

First dedicated cellular CT on the market

This is the first low-cost dedicated cellular CT available on the market. Other CT products are available on the market, but they are either unconnected loggers that have to be retrieved and uploaded or are connected to gateway devices that cost well over $1,000 and don’t stand alone.

CT’s are sized and based on the electrical current used on one leg of an alternating current wire. Sizes can go from 5 to 200 amps in the SCT-0750 line and up to 3,000 amps on other parts of the Magnelab CT lineup.

Virtjoule cellular CT with Magnelab 20 amp CT

A Must-Have Tool for Energy Auditors, Retro-Commissioning, and Service Providers

A cellular CT will become a must-have tool. Energy auditors, retro-commissioning specialists, and service providers are all aware of the basic usefulness of a regular handheld CT. 24/7/365 monitoring via CT gives you the ability to isolate a single component of a machine or the flexibility to find the variable energy use of an entire machine.

Virtjoule has been known for excellent fault detection capabilities and using a CT is now one more way to tap into fault detection capability in addition to understanding the energy usage of a machine.

True RMS

The Virtjoule Juice Cellular CT is a True RMS sensor. In addition to normal sinusoidal power feeds, it can be used to accurately measure amperage on variable speed devices and other pulse width modulated machines where computing the True RMS is key to knowing the correct amperage. Knowing correct amperage is critical to knowing how much power a machine is using and, for that matter, what parts of the machine are running.

How can you use a Cellular CT?

Cycling and hours of operation

Use the Cellular CT to pick up runtime information which includes amperage levels, cycling behavior, and hours of operation.

Failing compressors

It’s a well known fact that most aging compressors will begin to draw more amps, not only on startup, but at runtime as well. We have seen a recent example where amperage monitoring showed that a compressor was at the end of its life and we caught the actual failure when it happened. Monitoring amperage can give you insight into machine life expectancy issues.

Locating energy wasters

Use the Cellular CT to do sub-metering on selected units. With power output estimates from known amperage, it’s now possible to find those energy hogging machines.

Use the Cellular CT to demonstrate how much after hours operations cost. By monitoring the machine 24/7, you know when it is running after hours. Because you now have amp information, along with voltage and power factor it’s now possible to closely estimate how much after hours operations are costing. Virtjoule can help you do that.

Monitor complex behavior of individual components

Cellular CTs can be used to monitor specific electrical components of a much more complex machine. For instance, you can know conclusively at any time how many stages of compressors are being used in a large package unit. Also, estimating energy usage on larger and more complex machines can be very inexact because you can only estimate just exactly how the machine is used. Rules-of-thumb break down, particularly on larger machines. Now you can find out exactly how the machine is being used and how it’s performing.

Because amperage can be turned into power information and because we’re taking 10 second averages of amperage, you can get very accurate estimates of power usage on any electrical machine, motor, or other electrical component of a machine.

Multi-tenant situation, expense sharing

Do you have a multi-tenant situation, but sub-metering is not possible? Use Cellular CTs to understand power use across shared machines or electrical input and allocate costs appropriately and fairly.

Comparing a standard “clamp meter” with Virtjoule Juice Cellular CT

Clamp vs Cellular CT

Available now

Virtjoule Juice Cellular CT is available now. Call us today to discuss how Virtjoule Juice Cellular CT can help you or your clients and get your order in for this first of a kind monitoring device.

[Randy Cox - CEO and co-founder of Virtjoule - He is the software designer and analytics engineer for Virtjoule Sense sensors. He studied Chemical Engineering and Petroleum Refining at the Colorado School of Mines. You may contact Randy at: randy at virtjoule dot com] – See more at: http://blog.virtjoule.com/

Jan

Property owner and tenant incur extra 20% HVAC expense on BAS building

Posted by randy at 1:57 pm

Summary

A Trane Tracker controlled office and warehouse building had a rogue schedule, resulting in a HVAC bill that was 20 percent higher than necessary for the tenant. The building had 10 roof-top units (RTU’s), including one CRAC (Computer Room Air Conditioning) unit and nine package units. In addition to running during normal operating hours, all nine RTU’s were showing runtime on Saturdays — when the building was unoccupied. Neither the owner nor tenant were aware of the issue. Simply put, these machines were operating 20 percent longer than needed which not only led to higher HVAC expense for the tenant but, ultimately, would have shortened the lifetime of the equipment, reducing the property owner’s ROI.

Although BAS (Building Automation Systems) can streamline and help control a big facility, mistakes in BAS programming are often compounded — or missed altogether — without monitoring tools. As buildings with BAS get passed from tenant to tenant and HVAC service to HVAC service, valuable knowledge is often lost as to how the BAS and subsequent schedules were set up. It can be tedious and expensive to recommission the building and do a full audit of schedules within the BAS. Until there is a complaint, these sort of problem situations can drag on for months or years, wasting energy and money.

Key Concepts

Mistakes in BAS programming can be magnified across a building system, resulting in higher than necessary expenses, and still not be readily apparent.
Programming of BAS, if properly done, has benefits for both the property owner and the tenant(s).
Many BAS, if not most, lack the kind of internal monitoring controls that can uncover these money-wasting mistakes.
BAS systems are complicated and system knowledge is often lost when new tenants move in or when HVAC services are switched.

The facility we were working on is a typical high tech office building with an attached warehouse area. It has a total of 10 units, one Trane Voyager used as a CRAC unit and 9 other Trane Voyagers of various vintages. All the units that we were monitoring were on the roof of the building.

BAS controlled building running after hours

Two story office, one story warehouse space

Soon after Virtjoule’s HVAC monitoring sensors were installed on the Trane Voyagers, it became apparent that there was a scheduling problem with the building. All the units would start up on Saturday mornings at, but not exactly on, their normal weekday hour. The slightly different start time was the first clue that an extra schedule was in the system. Shutdowns were often at the same time as the weekday schedule for each unit.

This is a professional building with product developers and executives and featuring some manufacturing and warehouse space. Although employees can come in on the weekend, there is no need for the building to be completely heated or cooled for just a few people. Employees do have access to thermostats to regulate heating or cooling if they wish.

The building engineer was alerted and initially puzzled by the situation since he thought the building should be in “unoccupied mode”. He proceeded to work carefully through the BAS system and located the rogue schedule.

Because the rogue Saturday schedules were so similar to the weekday schedule, it’s easy to see that the owners of this facility have now reduced the wear and tear on the equipment they own by one day a week — or 52 days a year! The tenant is saving over 16 percent on their HVAC expenses (having paid 20% more than they should have) and presumably, over a longer period of time, will save on maintenance as the number of calls should decrease.

[Randy Cox - CEO and co-founder of Virtjoule - He is the software designer and analytics engineering for Virtjoule Sense sensors. He studied Chemical Engineering and Petroleum Refining at the Colorado School of Mines. You may contact Randy at: randy at virtjoule dot com]