Human errors can occur during installation and configuration. For additional confidence that panels are metered correctly, our standard recommendation is to add an additional 3 CTs to full panel metering, also known as a shadow metering configuration. With this configuration, we can perform a checksum on the panel and provide an additional reassurance that data is flowing accurately.
You can still be confident in the Verdigris data without this configuration, but many customers find it’s an inexpensive way to add an additional layer of confidence.
For a portfolio-wide rollout, this is even more critical because the complexity of achieving data integrity increases. You may be dealing with several different third party installers, different support staff responsibilities by region, and installation procedures may vary by site. For example, different access policies may prevent an installer from executing the standard validation process. Shadow metering configuration can help catch errors that arise from the challenges of achieving data integrity at scale.
The following table can help you determine whether shadow metering configuration is recommended for your implementation:
Situation | SMC? | Recommendation |
Full panel metered, ≤39 circuits | Yes | Our standard recommendation is to add an additional 3 CTs to full panel metering, in order to perform a checksum on the panel and provide an additional reassurance that data is flowing accurately. |
Full panel metered, 40-42 circuits | No | If 40-42 circuits are metered on a panel, there aren’t enough available channels to add shadow metering configuration.
If you would like the reassurance that the checksum provides, we can scope it for other panels as a spot check in your overall deployment. |
Partial panel metering | No | If we’re not metering the entire panel, the SMC checksum won’t match up.
If you would like the reassurance that the checksum provides, we can scope it for other panels as a spot check in your overall deployment. |
Mains only | No | It is far less likely to have a configuration error when metering mains only, very difficult to mess up installation and configuration, no redundant shadow metering configuration needed. |
Mains monitored by an upstream meter | No | If the mains are already monitored by another meter upstream, that meter can be used for the checksum verification. |
Additional Q&A
Q: If I don’t add shadow metering configuration, does that mean my data isn’t accurate?
A: No, Verdigris stands behind the accuracy of its energy meters. Your data will still be accurate if the meters were installed and configured correctly. The shadow metering configuration simply is an inexpensive way to add a layer of reassurance, and catch errors that may have occurred during installation and configuration.
Q: Is it ok to have shadow metering configuration on some panels but not others?
A: Yes. Many customers will have a mix of panels, some with shadow metering configuration, some without. In this scenario, the panels performing the checksum serve as a reassuring spot check for the overall deployment.
Q: Is shadow metering configuration required?
A: This is our standard recommended configuration for full panel metering, but it is not required.
Q: Are there other benefits to shadow metering configuration?
A: Yes. For customers who want to monitor power factor (PF) at a building level, shadow metering configuration ensures that you are protected from unmonitored changes at a specific panel level. For example, if the facility adds a couple of new panels to support a new chiller, but doesn't add CTs on them, it is important to ensure that reporting at the building level is not impacted. For the most accurate full building PF measurements, CTs must be installed at the incoming low-voltage cables or bus bars of the primary or master switchboards or switchgears.