Application Guide

63-7062 30
EXCEL VRL
APPLICATION GUIDE
APPLICATIONS
—
Fans.
—
Pumps.
—
Mixers.
—
Boilers.
—
Compressors.
—
Conveyors.
—
Elevators.
—
Machine Tools.
—
Textile machinery.
—
Paper and film manufacturing.
VFD OVERVIEW
Honeywell has long been aware of the full benefits of VFDs, and has installed them in a wide range of applications from fans,
pumps, and compressors to machine tools, elevators and textile machines. The following applications are a sample of some of
the installations and are intended to give an understanding of how a VFD can be utilized in the heating, ventilating, air
conditioning (HVAC) and other industries. See Fig. 35.
M
M
T
M
x
s
T
DP
+
-
T
M
DP
T
Honeywell
EMC
Controller
NOTE: One inverter could be used, but two will provide better control
RST
PG
MONPARREFBTNS
RUNREADYFAULT
Honeywel
l
RST
PG
MONPARREFBTNS
RUNREADYFAULT
Honeywel
l
Fig. 35. Constant Air Volume (CAV) application diagram.
Application Description
A Constant Air Volume (CAV) System controls space temperature by altering the supply air temperature while maintaining
constant airflow. The system design provides sufficient capacity to delivery supply air to the space for design load conditions.
Only at maximum load conditions - full heating or full cooling - is maximum air flow required, at other periods it is perfectly
feasible to vary the airflow while maintaining design conditions. Installing a VFD and linking into the existing temperature
controls, allows the air flows to be varied relative to load conditions (see Fig. 36). The motor will only run at full speed when
full
heating
or
full cooling
is called for.