Home TechTime March 2017 HVAC Controls
TechTime is a Neptronic publication aiming to inform you on the best ways to deal with common issues highlighted by our technical support team. Each edition features three new topics and will be posted on neptronic.com.

Thinking Outside the Fan Powered Box
User Permissions & Restrictions

There are many features to limit or restrict users from changing setpoints or configuration settings. These settings are usually not activated in the default configurations since most clients want to give some freedom to the user. However, to avoid problems caused by illogical setting changes made by some users, a few restrictions can be added. Here are the configurations available;


  • Temperature Setpoint: AV15 Temp Setpointis the actual zone temperature setpoint. This setpoint can be locked, or it can be limited:
    • Limitations: AV16 Min Setpoint & AV17 Max Setpoint are used to limit the setpoint range. The user cannot go lower or higher than those two values. These setpoints are applied to AV1 Control Temp.
    • Lock setpoint: BV2 Temp Setpoint Lock is used to lock the setpoint. When activated, the user cannot change this value regardless of the Min and Max settings.

  • User Off Mode: If you want to allow the user to turn Off the EVC controller via the thermostat, then BV3 User Sys Off Mode should be enabled. To restrict the user from turning off the EVC controller from the thermostat, disable this setting. If this setting is disabled, the BMS can still turn off the controller.

  • TRL button (keypad) lock:There are four options to lock buttons on the TRL;
    • BV7 Key Pad Upper Left Lock: The star button changes the mode of the zone.
    • BV8 Key Pad Bottom Left Lock: The back arrow button toggles the temperature units of the thermostat between °C and °F.
    • BV9 Key Pad Arrows Lock: The up and down arrow buttons change the setpoint.
    • BV10 Program Lock: This feature locks all buttons on the TRL. Note that if you are using Occupancy or Night setback features, the program lock will prevent the user from overriding the schedule.

  • User Zone Mode: Even though the literature and description of the object is MSV17 User Sys Mode Select, this feature allows or restricts the user in the mode choices of the zone (not the system). These are the options;
    • Auto: The user has permission to change the zone mode between Automatic, Cooling only, Heating only, Cooling/Heating, and Off (if BV3 is enabled).
    • Heating: The user is restricted to Heating only mode and Off (if BV3 is enabled).
    • Cooling: The user is restricted to Cooling only mode and Off (if BV3 is enabled).
    • Heating or Cooling: The user is restricted to Heating/Cooling modes and Off (if BV3 is enabled).
    • Auto Lock: The User is restricted to Auto mode and Off (if BV3 is enabled). This can replace BV7 Key Pad Upper Left Lock.
    • Zone Mode: As mentioned previously, there are two possible modes, the system and the zone. The system mode is the mode of the central system (cooling or heating) and is determined by a changeover or a status of the central unit. The zone mode is based on the demand of the zone (below setpoint requires heat and above setpoint requires cool). These two modes will dictate the behavior of the EVC along with the motor ramp. MSV16 User System Mode description is not accurate since it represents the mode of the zone that the user has selected (not the system). This selection can be changed via this object and is restricted by MSV17 User Sys Mode Select. Here is a little description of the options;
      • Auto: Zone mode changes automatically from heating to cooling (and vice versa) according to the demand.
      • Heating: Zone will operate with a heating demand. Cooling demands are ignored.
      • Cooling: Zone will operate with a cooling demand. Heating demands are ignored.
      • Off: The EVC is disabled by the user.

The user mode selection can create much discomfort in the zone. Make sure that the flame and snowflake icons appear at the bottom of the TRL with an “A” (automatic) in between. This confirms that the mode is still active for heating and cooling in automatic mode. If one icon is displayed without the Automatic symbol, the mode has changed and will not respond in the mode of the missing icon.