Glossary
PKG-SVP01E-EN
49
Applies to the control of the rooftop unit during
unoccupied periods. Also refers to the NSB panel, a
communicating wall sensor with night setback capability.
O
OA Reset
Outdoor Air Reset - Supply Air Temerature Reset based
on Outdoor Air Temerpature.
Occupied Zone Low Temerature Limit Setpoint
The temperature that initiates daytime warmup.
P
Purge
A function which causes zone air to purge and be
replaced by outside air.
R
Reference Enthalpy
An outdoor enthalpy value above which economizing will
be disabled.
Remote Human Interface
A human interface module designed to be mounted
remotely from the unit. There are some functional
differences between a unit mounted and a remote
mounted human interface module.
Reset Amount Maximum
The maximum amount of reset allowed.
Reset End Temperature
The temperature at which the maximum reset amount
will occur.
Reset Start Temperature
The temperature at which reset will begin.
S
Space Pressure
The pressure in the building as measured by the Space
Pressure Transducer, referenced to outside (atmospheric)
pressure.
Supply Air Pressure High Limit
A pressure limit to prevent unit casing and/or ductwork
over pressurization.
Supply Air Pressure
The pressure in inches water column (IWC) of the supply
duct plenum or outlet as measured by the Supply Air
Pressure Transducer, referenced to local outside
(atmospheric) pressure.
Supply Air Tempering
Turning on heat when the supply air temperature drops
below a preset value usually due to cold outside air being
brought in to provide building ventilation.
Supply Air Temperature Control Point
The revised value of supply air temperature SETPOINT
after supply air temp reset has been applied.
Supply Air Temperature Reset
A function that shifts the SA Temp SETPOINT an amount
based on the value of another parameter—typically Zone
Temp or Outdoor Air Temp. The purpose of this function
is to lower unit capacity to better meet load
requirements.
W
Water Purge
When the waterside economizer valve opens to flush out
the economizer tubes to prevent failure due to stagnant
water and sedimentation.
