Why is Timed Interval Sampling (TIS) Important?

POWERGEN uses TIS performance testing for 3 reasons:

  1. To provide undisputable real-time verification that an installed XL System is providing the proposed energy cost savings and increased efficiency of operational loads.
  2. The TIS testing technique remains the best method to verify true energy cost savings that are attributable to installed XL Systems.  The method of verifying energy cost savings in monthly electric bills by normalizing all possible variables (weather, production volume, occpancy, scheduled downtime, etc..) that can have an impact on monthly energy costs can be difficult and in some case impossible.      
  3. To confirm an XL System is optimally installed. POWERGEN energy managers use TIS results to make installation adjustments and tweak energy cost savings and efficiency performance.

POWERGEN Provides TIS Reports to Customers

POWERGEN provides TIS Test reports to customers that show differences in electrical performance when an XL System is activated and deactivated, these electrical measurements include:

  1. Real Power demand reductions (Watts)
  2. Voltage improvements across each phase (Volts)
  3. Amperage reductions across each phase (Amps)
  4. Reactive Power reductions (VAR)
  5. Apparent Power reductions (VA)
  6. Power Factor improvement (%)

POWERGEN Uses IPMVP Approved TIS Testing Techniques

To ensure accuracy, transparency and repeatability of TIS testing evaluations, POWERGEN uses TIS methods and techniques that adhere to the International Performance Measurement & Verification Protocols (IPMVP).  The IPMVP, endorsed by the U.S. Department of Energy, provides the best practices and techniques available for verifying energy cost savings and efficiency results of Energy Conservation Measures (ECM) like the XL Energy Conservation & Protect System.

Timed Interval Sampling (TIS) is a statistical method of energy measurement with regard to electrical consumption, measured as average wattage demand reductions over a short span of time. It is used in facilities with dynamic electrical loads where energy use is a function of manufacturing processes, environmental conditions, and related equipment.

TIS techniques are utilized to minimize the high degree of variables present when measuring energy consumption in facility electrical systems. These variables often include: weather conditions, facility operational techniques and load variations.

When an XL System is evaluated using TIS testing, the XL System is alternately activated (turned ON) and deactivated (turned OFF) at timed intervals such as 5, 10 or 15 minutes, to compare the average demand of real power by the loads in the facility under equal conditions. All samples are recorded and averaged in each respective operating condition (ON vs. OFF), in order to demonstrate the effects that the XL System has on the circuit when activated and deactivated.

POWERGEN uses the Amprobe DM-II Pro® Multi-meter Data Logger to perform TIS metering and recording. This “True RMS” meter meets the standards of the National Institute of Standards and Technology and the IPMVP.  POWERGEN also use Fluke 435 Power Quality Meters.

Evaluation of XL System performance is made through analysis of the data recorded from TIS testing. Amprobe DM-II Pro® Multi-meters are connected at a point near the main service breaker for the entire facility in order to measure overall circuit power quality and average energy savings. XL Systems are activated and deactivated for intervals of 5 and 10 minutes during the test period to measure changes in overall power quality in each operating condition.

A separate test of the cumulative effect of the XL System is also conducted to confirm each XL module is operating properly.

The differences between conditioned and unconditioned power quality is determined and averaged to demonstrate the overall effect an XL System has on the circuit.

  • All recorded TIS data is evaluated and averaged in the following manner to determine overall average performance of XL Systems: The average power quality for each full interval is calculated and compared to the next interval before and after each transition from on to off, and off to on.
  • Each instantaneous change in power quality is determined by comparing the last one- second with the XL System “ON” to the first one-second with the XL System “OFF” and vice- versa.
  • The average power quality is calculated before and 15-seconds after each transition from “ON” to “OFF”, and “OFF” to “ON”.
  • The average power quality is calculated before and 30-seconds after each transition from “ON” to “OFF”, and “OFF” to “ON”.  
  • The average power quality is calculated before and 45-seconds after each transition from “ON” to “OFF”, and “OFF” to “ON”.
  • The average power quality is calculated before and 60-seconds after each transition from “ON” to “OFF”, and “OFF” to “ON”.
  • All   representative   transitional   changes   are   averaged   to   derive overall   average performance of an XL System.