In Part 1 of this series, we established that detailed energy information is needed to create effective energy management programs. We also discussed that the most cost-effective and efficient way to obtain and share that information is by installing approved, standards-based multi-point meters combined with cloud-based reporting and meter management software.
In Part 2, we will discuss potential pitfalls when establishing a metering system and how to avoid them. Proper planning and design can mean the difference between a successful project that produces actionable data versus a poorly run project with cost overruns and quickly discarded information.
Five steps
A successful submetering project is carefully planned and artfully executed. If these five steps are followed, the deployed meters will provide building owners and property managers with the information they need (when needed) in a cost-effective manner.
1. Clarify project goals
2. Understand the electrical architecture
3. Design meter deployment
4. Install and configure the meters
5. Meter commissioning
1. Clarify Project Goals
The first step is to be very clear about why electrical energy information is required in the first place. Is it needed to bill actual electricity consumption to tenants? Do building managers want to understand energy usage patterns to modify consumption habits? Is the goal to identify failing equipment or poor building management practices? Is the desire to qualify for utility-based or government incentives?
Being clear on a project's goals makes it easy to pinpoint the type and amount of metering equipment needed. Utility billing and other revenue or performance-based applications will likely require meters that are listed with jurisdictional authorities. In contrast, energy management applications such as measurement and verification (M&V) or consumption benchmarking can typically deploy non-listed meters.
2. Understand the Electrical Architecture
The importance of good onsite information at the start of a metering project can't be overstated. Accurate data upfront will ensure that design is optimal and that installation and meter commissioning proceed smoothly.
The best records of the electrical system of a building are the single-line electrical schematic and panel schedules. These are readily available for new installations or facilities under construction. For older existing buildings, single-line drawings are often less accurate (if they exist at all), making a site visit mandatory.
Site visit information, coupled with knowledge derived from any electrical schematics or schedules that exist, should be recorded in a standard, easy-to-read format. This allows the information to be shared between the electrician, project manager, system managers and support staff.
At Triacta, we use a spreadsheet system that supports both paper-based and electronic data collection. The spreadsheet information is compiled by those conducting the site survey and shared with the rest of the team — so everyone works from the same base assumptions.
3. Design Meter Deployment
This step determines the number of meters deployed, the meters' programming requirements, any additional system components needed, and how the metering system will communicate with other systems. Careful communication between team members at the design stage saves money, time, and effort down the road. It also ensures data can be easily shared with energy management, billing, and building management systems.
It's essential to have a meter deployment platform that supports all aspects of the metering project — from meter installation, configuration, and diagnostics, to billing, measurement, verification, and system integration.
For more on the need for a secure, cloud-based platform for meter deployment, configuration and ongoing management, see The Importance of Cloud-based Meter Management.
4. Install and Configure the Meters
Under most building codes, installing multi-point meters requires a licensed electrician as current transformers will have to be installed directly on the electrical service conductors inside the panel. If solid-core, revenue-grade current transformers (CT) are to be used (necessary for accurate revenue applications), conductors will have to be disconnected.
The importance of a thorough site survey or single-line drawing analysis is emphasized during this part of the process. This analysis will determine wiring and voltage configurations along with ampere ratings. Amperage determines the CT’s necessary for use with the meters.
Once installed, meters must be configured for the required application. Meter configuration includes the type of electrical service (i.e. 3 phase 3 wire, 3 phase 4 wire) and voltage and amperage requirements. Also, information about the communication network must be entered to ensure the meters report to the metering platform and any energy management, billing, or building management network as required.
Meter configuration is often performed onsite using a web page connection or specialized computer application. Onsite configuration is not ideal as mistakes can be made during data entry that may not be discovered until later in the process. An alternative method is to pre-program meters before shipping them to the site. Unfortunately, this can cause issues if programming errors are discovered or suspected once technicians have left.
Triacta uses cloud-based software to configure meters. Once installed and reporting to Triacta Meter Manager, meters can be configured remotely — saving time and reducing costly site visits.
5. Meter Commissioning and Ongoing Monitoring
Commissioning is simply the process of generating a service load in the panel (turning on power to a load such as lights) and ensuring that the meter sees the load correctly. If required, meter verification would occur at this point to ensure the meter conforms to any applicable regulatory requirements.
Beyond viewing energy consumption information, the metering network should be monitored to ensure ongoing success once in place. A cloud-based management system allows for easy remote diagnostics, maintenance and support.
Multi-point meters are the most cost-effective solution for the granular monitoring of a building's energy consumption. Still, care must be taken to ensure the platform is deployed correctly. Following the 5 steps outlined here will ensure a successful, cost-optimized deployment.
