48
PKG-SVP01E-EN
Glossary
A
Active SETPOINT
The SETPOINT which is currently being used for control
by the SETPOINT source selection.
B
BACnet
®
An open, device networking communications protocol for
controls. This protocol utilizes BACnet and ANSI/ASHRAE
Standard 135-2004 protocol which provides building
owners the capability to connect various types of building
control systems or subsystems together.
C
Compressor Lockout
All affected compressors stop and remain off until the
condition resets or is manually reset.
Compressor Protection Switch
A pressure switch installed on the suction line that
prevents compressor operation below the switch’s
SETPOINT. The purpose is to prevent no-flow scroll
compressor operation.
Control Band
The range of temperatures or pressures which would
normally be maintained by the various control functions.
Control Point
The value of a SETPOINT that an algorithm is using at any
given time.
D
Deadband
As applied to SA temp control, this refers to a range of
temperatures equally spaced above and below the SA
temp control point in which the control algorithm is
satisfied.
Dry Bulb
An outdoor temperature above which economizing will be
disabled (unless comparative enthalpy is the economizer
control type being used.)
E
Economizer Zone Temp SETPOINT Suppression
a parameter used for setting the Zone Temp SETPOINT at
a lower value than the mechanical cooling zone temp
SETPOINT.
External Heat
A heat source external to the self-contained unit that is
field installed (i.e. duct heat or VAV reheat boxes).
External Stop
A binary input on the RTM that allows unit shutdown,
with automatic reset, when connected to a field-supplied
switch.
H
Hydronic Heat
Optional steam or hot water heat coil.
Independent Refrigerant Circuit
All model SCWG/SIWG, SCRG/SIRG and SCWF/SIWF
units have independent refrigerant circuits.
I
Interprocessor Communications Board (IPCB)
Option
The IPCB is used to expand communication from the
unit’s UCM network to a remote human interface panel.
DIP switch settings on the IPCB module for this
application should be; switches 1 and 2 “off,” switch3
“on.”
L
Low Ambient Compressor Lockout
A function which prevents compressor operation at low
outdoor ambient temperatures.
Low Entering Water Temperature
When the entering water temperature sensor reads a
water temperature below the minimum water
temperature input into the controller. The factory preset
temperature is 54° F.
Low Entering Water Temperature Compressor
Lockout
On units with head pressure control disabled and an
entering water temperature below 54° F, compressor
operation disables. economizer operation is still
functional.
M
Manifold Refrigerant
Circuit Only model SCRF/SIRF units, 30-60 tons, have
manifolded refrigerant circuits.
N
Night SetBack (NSB)
