Determine if two units that should be staged are turned ON at the same time, without sufficient delay

Applicable Systems

• Primary: CHLR, BLR

Description / Method

Monitors two equipment status or command TLs, and counts the number of times they are being enabled (ON) at the same time. Generates an insight if the equipment turns ON at the same time for more than once a week (user adjustable). Generates a CTL for weekly counts. {BLR,CHLR}

Logic

Normalize all inputs to 5 minute intervals. Check each equipment is on (amps above threshold). Sum the times over the week that both values are true.

sum time over the week {
   Temp_Diff = CHLR_Temp - CHLR_SP
   if(Temp_Diff = 0, No_Insight, Insight_Flag)
   }

Diagnosis / Recommended Action

1. Review and optimize the control sequence so that units can be staged rather than enabling them simultaneously. The time delay allows to monitor and evaluate the actual demand.

Message

Units that should be staged are enabled at the same time without sufficient delay. Please review equipment control.

Notes

All time-spans and thresholds are adjustable. Additional unit status or command trend logs could be added if the system involves more than two units (example: three chillers, three boilers etc.). Input TLs use 5 min constant normalization.

Defaults used: Constant-Weekly_Sum_Threshold: 1 Unit ON Analog Threshold: 1

Rule Template Type

• Insight Type: Fault Detection
• Trigger Type: Active High

Default Priority

Medium

Inputs

Inputs	Units	Tags	Description
Unit 1 Binary/Analog Status {}	0/1 or Amps	status|cmd	Equipment 1 On/Off Indicator
Unit 2 Binary/Analog Status {}	0/1 or Amps	status|cmd	Equipment 2 On/Off Indicator

Constants

Inputs	Units	Default Value	Description
Unit ON Analog Threshold	Amps	1	Analog amperage threshold for equipment is on. Set this to 1 when using binary input
Constant-Weekly Sum Threshold	hours	1	Threshold hours per week that both equipment are running

Output Calculated Trend Logs

Output CTL	Units	Frequency	Description
Weekly_count_units_enabled_simultaneously	hours	weekly	Cumulative time that both units are on for the week.