Optimum Start/Stop / Eoh3 - Honeywell EXCEL 5000 User Manual

EXCEL CARE CONTROL ICONS
Optimum Stop
• Connect a space sensor.
• Set space temperature setpoint greater than 64.4F (18C).
• Enable adaptation (P14).
• Ensure the following conditions:
- Average OAT must be less than 59F (15C).
- Adaptation must occur at least three times before you can alter the defaults for
the basic setting of the heating curve.
EOH calculates the optimum stop period based on outdoor air temperature:
Depending on whether or not a room temperature sensor is connected, software
may further modify this optimized stop period, for example:
• Increase if room temperature is greater than room setpoint (maximum 2 hours).
• Decrease if room temperature is less than room setpoint.
At the calculated stop time, software resets discharge air setpoint to zero and
changes digital output YD3 to logic 1. YD3 remains at logic 1 until optimum start
(next day or later).
Function Calculate optimized values for starting and stopping the heating plant and for the
supply water setpoint. The EOH3 function considers the residual heat in a building
to avoid unnecessary heating operation and, thus, save energy. Required room
conditions are met at all times.
EOH3 calculates the required flow temperature according to an integrated heating
curve.
There are two optimization options:
• optimization without room sensor
• optimization with room sensor
Optimization without a room sensor uses the outdoor air temperature to determine
the optimum start (preheat point).
Optimization with a room sensor uses the room control and needs a time constant
and dead time to calculate the preheat point.
Any kind of start or stop optimization requires a time program for the room
temperature setpoint.
Time program setpoint values are:
165
ALPHABETIC REFERENCE

Optimum Start/Stop / EOH3

EOH3
74-5577–33 (US)
EN2B-0184 GE51 R0518 (Europe)