Installation and Operation Manual
●
Fan Coil Controller – EZstat
EC-EZstat
Date: 9-2014
Supersedes: NEW
Engineered Comfort reserves the right to change any information concerning product or specification without notice or obligation.
Page 27 of 36
Procedure
Steps
Display
User lockout
buttons
Choose KEY LOCKOUT from the ADVANCED menu to limit accessibility to
users with Password 1, the user password.
•
MODE/SETPOINTS—Users with Password 1 cannot change any
value or mode.
•
MODE—Users with Password 1 cannot change the heating/
cooling, fan, or occupancy modes.
•
NONE—Users with Password 1 have full access to active
setpoints, heating/cooling, fan, and occupancy modes.
7 SEQUENCES OF OPERATION
Topics in this section cover the sequences of operation for the EZstat. These are advanced topics for control’s technicians and
engineers.
This section covers the following sequences of operation:
• Setpoint Limits
•
Occupancy
•
Automatic cooling and heating changeover
•
Scheduling occupancy
•
Display blanking and backlight
•
Temperature sensing inputs
•
PID control loops
•
Valve operation for fan coil units
•
Fan operation for fan coil units
7.1 Setpoint Limits
The programming in the EZstat will limit the setpoint entry so that no heating setpoint is set higher than its corresponding
cooling setpoint.
If a user is adjusting a setpoint and it falls within the range set by the value of Minimum Setpoint Differential, the
corresponding setpoint will be changed to maintain the differential. For example, the Minimum Setpoint Differential is
4° F and the Occupied Heating setpoint is 70° F. If the user lowers the Occupied Cooling setpoint to 71° F, the controller
recalculates the Occupied Heating setpoint and changes it to 67° F.
7.2 Occupancy
The EZstat is designed to operate as a stand‑alone controller and can determine occupancy based on its internal occupancy
schedule. The EZstat can be in any one of the following occupancy states.
• OCCUPIED
• UNOCCUPIED
The occupancy and standby states can also be commanded by another BACnet device or an operator workstation
connected to the building automation network.
Occupied
In controllers without a motion sensor, the EZstat starts in the occupied state. If the internal schedule is enabled, the state
of the schedule is set to either OCCUPIED or UNOCCUPIED as the initial state.
Unoccupied
The controller changes to the UNOCCUPIED state only if the internal occupancy schedule is enabled and if the schedule is
inactive.
