Emerson E2 Logging, Hourly, Daily, Monthly, Definition of Heat and Cool Degree Days

NOTE: If you do not wish to use load shedding for your building, simply do not connect any- thing to the SHED OUT output.

11.15.2 Logging

Power Monitoring applications are pre-programmed with extensive logging capabilities that record the hourly, daily, and monthly power usage statistics.

Hourly

The hourly log contains a list of power usage summa- ries of the previous 48 hours. An hourly log entry con- tains:

•The time and date of the entry

•The KWh for that hour

•The maximum average KW that occurred within any demand window for that hour

•The highest instantaneous KW reading taken for that hour, and the time that reading was taken

Daily

The daily log contains a list of power usage summaries for the previous 48 days. A daily log entry contains:

•The date of the entry

•The KWh for that day

•The maximum average KW within any demand window for that day

•The highest instantaneous KW reading taken for that day, and the time that reading was taken

•The total number of minutes the Power Monitoring application was in Shed Mode

•The Heat Degree Days for that day

•The Cool Degree Days for that day

Monthly

For monthly logging, the day of month can be user- specified so the day of the month on which the utility bill- ing period starts can be accurately compared to the utility bill. The monthly log contains a list of power usage sum- maries for the previous 24 months. A monthly log entry contains:

•The month and year of the entry

•The KWh for that month

•The maximum average KW within any demand window for that month

•The highest instantaneous KW reading taken for that month, and the date and time the reading was taken

•The total number of minutes the Power Monitoring application was in Shed Mode

•The Heat Degree Days for that month

•The Cool Degree Days for that month

Definition of Heat and Cool Degree Days

Heat degree-days and cool degree-days are standard industry measurements of the demand for heating and cooling. This measurement is based on the daily average outdoor air temperature.

If the daily average temperature is below 65°F, then the number of heat degree-days for that day is equal to 65 minus the day’s average temperature in degrees Fahren- heit. Example: if the day’s average temperature is 54°F, the number of heat degree-days for that day is 65-54 = 9 heat degree-days.

If the daily average temperature is above 65°F, then the number of cool degree-days for that day is equal to the day’s average temperature in degrees Fahrenheit minus 65. Example: if the day’s average temperature is 71°F, the number of cool degree-days for that day is 71-65= 6 cool degree-days.

Larger degree-day numbers indicate a larger demand for heating or cooling. Degree-day totals may be added together to indicate heating and cooling demand for weeks, months, or years. E2 does this to keep monthly logs of heat and cool degree-days.

11.15.2.1 Power Monitoring Input

The Input Type Selection parameter defines the way the Power Monitoring input (INPUT under the Inputs tab in application Setup) will be used. The parameter can be set to: KW Analog, Pulse KWH, Current (Amps), or Current 3-phase.

Settings

When KW Analog is selected, verify the input is con- nected to a board and point that is set up with Engineering Units of KW. When Pulse KWH has been selected, verify the input is connected to a board and point that is set up with Engineering Units of KW. When Current (Amps) has been selected, verify the input is connected to a board and point that is set up with Engineering Units of Amps. When Current (3-phase)has been selected, verify the input is connected to a board and point that is set up with Engineering Units of Amps. Note that for 3-phase, three power monitoring inputs will appear under the Inputs tab of the application. All inputs must be connected to board and points set up with Engineering Units of Amps.

11-44 • E2 RX/BX/CX I&O Manual 026-1610 Rev 13 14-SEP-2011