GLOSSARY:

This glossary is intended for Vortechs clients. It provides definitions for terms relevant to their installed automation systems.

Any Occ
"ON" if any VAV (Variable Air Volume) zone in Occupied mode. Expected: Depends on VAV occupied status.

Cool 1 MOT
Cooling stage 1 Minimum ON Timer. Expected: Counts up to the Cool MOT SP (Set Point) when the cooling is turned on. The cooling stage will not turn off until the SP is reached.

Cool 2 MOT
Cooling stage 1 Minimum ON Timer. Expected: Counts up to the Cool MOT SP when the cooling is turned on. The cooling stage will not turn off until the SP is reached.

Cool Minimum On Time Set Point
Cooling stage minimum ON time. Default: Varies by size and type of cooling equipment -typically 120 seconds or more.

Cool Timer
This timer controls the cycling of the cooling within the cycle defined by the Cool.

Cool Timer Set Point
Used for DX (need definition) cooling. Sets the total cycle time for cooling stages. Default: Depends on the equipment. Typical 600s or higher. This will determine the maximum total starts per hour. (600s = maximum of 6 starts per hour).

Control System
An HVAC control system is a computerized control system for climate control in buildings.

Cool 1 Start
Used in single PID (proportional integral derivative) discharge temp control. Sets the percentage of the Discharge Air Temp PID at or below which the first stage cooling will be at 0%. Default: Depends on tuning. Typical initial value 55% Note: should always be somewhat HIGHER than the Heat 1 Start value to provide a deadband against conflicting operation of heating and cooling.

Cool 1 End
Used in single PID discharge temp control. Sets the percentage of the Discharge Air Temp PID at or above which the first stage cooling will be at 100%. Default: Depends on tuning. Typical initial value: 80%

Cool 2 Start
Used in single PID discharge temp control. Sets the percentage of the Discharge Air Temp PID at or below which the second stage cooling will be at 0%. Note that the second stage of cooling reaches 100% when the Discharge Air Temp PID reaches 95%.Default: Depends on tuning. Typical initial value: 75%.

Cool 1 Percent
The calculated value for Cooling stage 1 based on the Discharge Air Temp PID. Value and the Cool1 Start and End values. Expected: 0-100%.

Cool 2 Percent
The calculated value for Cooling stage 2 based on the Discharge Air Temp PID value and the Cool2. Start and End values. Expected: 0-100%.

Cool 1 Time SP
The time for Cool Stage 1 to be on of the total cycle time for cooling stages. This will be a number of seconds corresponding to the Cool 1 Percent as a Percentage of the overall heat cycle time in the Cool Timer SP. Expected: 0 - Cool Timer SP, depending on the value of Cool 1 Percent.

Cool 2 Time SP
The time for Cool Stage 2 to be on of the total cycle time for cooling stages. This will be a number of seconds corresponding to the Cool 2 Percent as a Percentage of the overall heat cycle time in the Cool Timer SP. Expected: 0 - Cool Timer SP, depending on the value of Cool 2 Percent.

DAT
Discharge Air Temperature.

DAT Filter SP
The percent of change of the actual Discharge Air applied each second to the Filtered DAT value. If this number is 1, the altered DAT will track the actual DAT. The smaller the number, the slower changes in the actual DAT will be reflected in the Filtered DAT value. Default: Depends on tuning. Typical initial value 0.1.

DAT LOW SP
The low limit for Discharge Air Setpoint. Default: Varies by system. Typically not higher than 50.

DAT HIGH SP
The high limit for Discharge Air Setpoint Default: Varies by system. Typically not higher than 100.

DAT Reset High
The highest value that the DA temperature setpoint will reset to as the outside air temperature varies between its Reset High and Low values Default: Varies by system. Typically not higher than 100.

DAT Reset Low
The lowest value that the DA temperature setpoint will reset to as the outside air temperature varies between its Reset High and Low values Default: Varies by system. Typically not lower than 50.

DAT SP
Discharge Air Temperature setpoint Expected: Varies between the values set for DAT Reset High and DAT Reset Low.

DDC
Direct Digital Control is (DDC) is a protocol that provides analog or digital outputs to control HVAC system devices.used to control HVAC systems.

DP
Discharge Air Pressure.

DP SP x 100
The discharge air pressure setpoint multiplied by 100. (The PID needs large numbers). Expected: 100 x the actual discharge air pressure setpoint.

DP x 100
The discharge air pressure multiplied by 100. (The PID needs large numbers) Expected: 100 x the actual discharge air pressure.

Duct Pressure SP
Desired supply duct air pressure. Default: Varies by system, typically between 1” and 2”.

Fan Fail
ON when fan has failed to prove by duct pressure. Expected: OFF. This alarm latches ON and must be reset by the operator by clicking.

Fan Proof
ON when the fan is proved by the duct pressure being above the Fan Proof SP. Expected: Depends on fan proof status.

Fan Proof SP
The supply duct pressure at which the fan is proved ON. Default: Varies by system. Typically at least 0.2”

Filter High SP
The filter pressure alarm setpoint Default: Varies by system and filter media used. Typically at least 0.5” ON when the filter pressure has been above the Filter High SP. Expected: OFF. This alarm latches ON and must be reset by the operator by clicking.

Filtered DAT
Discharge Air Temperature after time filter. See DAT Filter SP Expected: Slowly follows the actual Discharge Air Temperature.

Global Shed
System wide global shed request Default: 0 – 100% depending on overall building energy management requirements.

Heat Timer
This timer controls the cycling of the heating within the cycle defined by the Heat Timer SP. Expected: When heating is called, it counts up from 0 to the Heat Timer SP, resets to 0 and repeats. When heating is not called, it remains at 0.

Heat Timer SP
Used for DX, gas or electric heating. Sets the overall cycle time for the heating stages. Default: Depends on the equipment. Typical values are: Solid state heat: 10s. Gas heat: 120s, Heat Pumps: 600s.

Heat MOT SP
Heating stage minimum ON time. Default: Varies by type of heating equipment. Solid State Relay control for electric heat can be 0 seconds. Gas heat or heat pumps may need 120 seconds or more.

Heat 1 MOT
Heating stage 1 minimum ON timer. Expected: Counts up to the Heat MOT SP when the heat is turned on. The heating Stage will not turn off until the SP is reached.

Heat 2 MOT
Heating stage 2 minimum ON timer. Expected: Counts up to the Heat MOT SP when the heat is turned on. The heating. Stage will not turn off until the SP is reached.

Heat 1 Start
Used in single PID discharge temp control. Sets the percentage of the Discharge Air Temp PID at or above which the first stage heating will be at 0%. Default: Depends on tuning. Typical initial value 45%. Note: should always be somewhat LOWER than the Cool 1 Start value to provide a deadband against conflicting operation of heating and cooling.

Heat 1 End
Used in single PID discharge temp control. Sets the percentage of the Discharge Air Temp PID at or below which the first stage heating will be at 100%. Default: Depends on tuning. Typical initial value 20%.

Heat 2 Start
Used in single PID discharge temp control. Sets the percentage of the Discharge Air Temp PID at or above which the second stage heating will be at 0%. Note that the second stage of heating reaches 100% when the Discharge Air Temp PID reaches 5%. Default: Depends on tuning. Typical initial value 25%.

Heat 1 Percent
The calculated value for Heating stage 1 based on the Discharge Air Temp PID value and the Heat 1 Start and end values. Expected: 0-100%.

Heat 2 Percent
The calculated value for Heating stage 2 based on the Discharge Air Temp PID value and the Heat 2 Start and End values. Expected: 0-100%.

Heat 1 Time SP
The time for Heat Stage 1 to be on of the total cycle time for heating stages. This will be a number of seconds corresponding to the Heat 1 Percent as a Percentage of the overall heat cycle time in the Heat Timer SP. Expected: 0 - Heat Timer SP, depending on the value of Heat 1 Percent.

Heat 2 Time SP
The time for Heat Stage 2 to be on of the total cycle time for heating stages. This will be a number of seconds corresponding to the Heat 2 Percent as a Percentage of the overall heat cycle time in the Heat Timer. SP. Expected: 0 - Heat Timer SP, depending on the value of Heat 2 Percent.

Heat S2 Delay SP
This is the delay (in seconds) between the call for first stage heating and the allowance for the second stage of heating. Default: Caries by system. Typically started at 900.

Load shedding, is an intentionally-engineered electrical power stoppage. In building controls, load shedding is performed when building demand nears a pre-set target. Typically, load shedding occurs on non-essential equipment or equipment that is not required at that moment.

Max Call
Maximum call from any VAV zone. Expected: Varies between 0 and 100% depending on VAV zones.

Max Call SP
This is the setpoint sent to the Discharge Air Controller. It is based on the call from whichever Zone on the system that is the most above setpoint. Expected: This value will vary depending on the heating and cooling requirements of the zones on a system. It may be anywhere between 120 and 50.

Max Difference
The maximum amount that any VAV zone is above it’s setpoint. Default: 0 to ?? Degrees.

MAT DX LO
This setpoint provides a low MAT (Maximum Air Temperature) lockout for DX cooling. If the MAT is below this value, the compressors will be locked out. It has a 2 degree fixed dead band Default: Varies by system. Typically about 45-50.

Min OAD
The minimum Outside Air damper setting when the unit is in the Occupied mode. This represents the damper position and not necessarily the percentage of outside air which may vary with building pressure, duct configurations and other factors. Default: Varies by system, typically 10-15%.

Mixed Air Low Temp
The lowest temperature allowed for Mixed air temperature. The outside air damper will modulate closed on a PID to maintain this minimum in cold weather. Default: Varies by system. If water coils are used, set well above freezing. Typically about 45-50.

Modbus
A serial communications protocol published by Modicon in 1979 for use with its programmable logic controller (PLCs).

Net Sensor Thermostat
Local “smart” temperature/humidity with display and setpoint capability. These devices interact with controllers over the communication bus.

NS temp
The temperature as sensed by a Net Sensor type thermostat. Expected: Ambient temperature wherever the Net Sensor is located.

NS RH
The relative humidity as sensed by a Net Sensor type thermostat. Expected: Ambient humidity wherever the Net Sensor is located.

Occupied
ON if the unit is on the Occupied mode. Expected: Depends on schedules and operator overrides. OAT Reset OA High When the Outside Air Temperature is at or above this value the DAT setpoint the DAT set point will be reset to its low value. Default: Varies by system. Typically about 70.

OAT Reset OA Low
When the outside temperature is at or below this value the DAT setpoint Will be reset to its high value. Default: Varies by system. Typically not less than 10.

OAD Lockout Temp
If the OA temperature is below this value, Outside air will always be used to supplement cooling. Default: Varies by system, typically 65 or lower.

PID Controller
A proportional Integral Derivative Controller is a generic control loop feedback mechanism (controller) widely used in industrial control systems. A PID controller attempts to correct the error between a measured process variable and a desired setpoint by calculating and then outputting a corrective action that can adjust the process accordingly and rapidly, to keep the error minimal.

PLC
Programmable Logic Controller.

Shed
Unit compressor is shed for demand limiting. Expected: Depends on overall building energy management requirements.

Shed DB
This sets the temperature band in which the unit’s compressors will Be available for load shedding. When the temperature in any zone on an air handler is above the zone setpoint by more than this amount, its shed % will be at 100% and the cooling resource(s) for that air handler will no longer be available for shedding. Default: Varies by system, typically 5-8 degrees.

Shed %
This is the difference between setpoint and actual for the worst case zone on an air handler as a percentage of the Shed DB. If the Shed DB is 5 and the worst case zone is 2.5 degrees above setpoint, the Shed % will be 50. Expected: 0-100%, depending on conditions.

Shed Timer
The number of seconds remaining in a shed cycle. While this value is above zero, the cooling resource(s) will not run. Expected: 0 – the value of the Shed Timer SP.

Shed Timer SP
The time (in seconds) that an air handlers cooling resource(s) will be shed. Default: Varies by system. Typically 300 -600

System Enable.
Global Enable/Disable for the air handler. Disable shuts down all. functions. Default: Enable.

Timer Set Point (SP).
Expected: When cooling is called, it counts up from 0 to the Cool Timer SP, resets to 0 and repeats. When cooling is not called, it remains at 0.

Variable Air Volume (VAV)
Variable air volume is a technique for controlling the capacity of a heating, ventilating, and/or air-conditioning (HVAC) system.

Warmup Mode
ON if the unit is in Warmup Mode. Expected: Depends on schedules.

Warmup DB
Warmup deadband. Warmup mode will stop when the space temperature is within this value of the occupied setpoint.