Single And Two Stage Cooling With Economizer - Honeywell Design and Application Technical Reference Manual

Single and Two Stage Cooling With Economizer

TWO STAGE COOLING
COMMERCIAL THERMOSTAT
On a Call for Second Stage Cooling
Controller signal is routed to the economizer
logic module.
IF THE OUTDOOR AIR IS SUITABLE FOR
FREE COOLING AND THE OUTSIDE AIR
DAMPERS ARE OPEN:
The economizer logic turns on the first stage
of mechanical cooling for the second stage of
cooling required by the commercial
thermostat. With JADE
the OA damper wide open to try to satisfy the
call for second stage of cooling. If OA
dampers are 100% open and call for second
stage is not satisfied then the JADE
on the second stage mechanical cooling and
the OA damper will remain wide open.
TM
NOTE: JADE has an option in the
Advanced setup menu "STG3 DLY"
which is a delay after the stage 2 for
ECONOMIZER CONTROLLER
FIRST
STAGE COOL
Y1
SECOND
STAGE COOL
Y2
TM
the actuator drives
TM will turn
YES
OUTSIDE
AIR COOL?
NO
cooling has been active for a
programmed amount of time. If the
space has not been satisfied after the
programmed amount of time, the
TM
JADE
mechanical cooling to allow 3 stages
of cooling, 1 economizer and 2
mechanical. This feature can also be
turned off.
IF THE OUTDOOR AIR IS NOT SUITABLE
FOR FREE COOLING:
The first stage cooling compressor is on, and
the logic module turns on the second stage of
mechanical cooling.
NOTE: A commercial thermostat with a
minimum of two stages of cooling is
required. The first stage must be
available for economizing if outside air
is suitable.The OA dampers must be
opened completely on a second call
for cooling before the mechanical
cooling is turned on.
21
Section 1 - Ventilation
OPEN OUTSIDE
AIR DAMPER
MECHANICAL
COOL 1
MECHANICAL
COOL 2
COMPRESSORS
M13817A
turns on the 2nd stage of
Honeywell Economizers 63-8594-02