Determine if boiler system is slow to meet setpoint on startup

Applicable Systems

  • Primary: BLR

Description / Method

Determine if the supply temperature control is taking too long to reach its desired set point, on system start up. {BLR} Check the amount of time the HWST takes to reach within 4 degrees of its set point. This check only occurs after the system is enabled and before the temperature set point is reached.

Rule Template Type

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

Inputs

  • Hot Water Temp Sensor {sensor, leaving, hot, water, temp} (Real Trend Log)
  • Hot Water Temp Setpoint {sp, leaving, hot, water, temp} (Real Trend Log)
  • Equip status {cmd|status|occupied}

Rule Template Explanation

Logic

Determine if boiler system is slow to meet setpoint on startup

1. Input sensor(s) faulty or miscalibration. Verify input sensor(s) operation.

2. Heating water not available. Verify boiler plant operation.

3. Automatic control has been overriden. Revert equipment back to automatic control.

4. Issue with control loop. Review and modify controller tuning parameters.

Message

The time the boiler HWST takes to be within 4 degrees of set point on system startup is longer than 2.5 hours per week.

Notes

This logic flow only activates the initialization of the unit. If the temperature falls below the set point a second time, this will purposefully not trigger. However, this rule will activate every time a unit engages. If the unit changes status multiple times per day, a building occupancy trend log may be more suitable to define unit status.

Parameters

Parameter Expression Block Series Number Description Default Value (Units)
Temperature Threshold 89 The acceptable temperature range the HWST has to enter to be considered normal 4 (C)
Acceptable hours per day to reach Set Point 90 The amount of time that this error is allowable for the unit per day. Anything more than that time is considered a fault. 2.5 (h)