Program menu - continued – Greenheck Microprocessor Controller v3.0 (469690) User Manual
Page 18
18
Compressor Setup
# of stages:2
Minimum
ON:030s
Minimum
OFF:180s
T
HIS
SCREEN
DISPLAYS
THE
NUMBER
OF
STAGES
PROVIDED
WITH
THE
UNIT
AND
SHOWS
THE
COMPRESSOR
M
INIMUM
ON
AND
OFF
TIMES
(
IN
SECONDS
).
This screen only appears if DX cooling was provided with the unit.
The purpose of having minimum ON/OFF times is to prevent the compressor from short
cycling.
Do not change the defaults shown without consulting the factory.
Compressor Setup
Between stages:240s
Lead-Lag:YES
Lead-Lag Time:100hrs
T
HIS
SCREEN
DISPLAYS
THE
DELAY
TIME
BETWEEN
STAGES
,
ALONG
WITH
THE
L
EAD
-L
AG
TIME
PROGRAMMED
FOR
THE
COMPRESSORS
.
This screen only appears if 2-stage DX cooling (2 compressors) was provided with
the unit.
Between Stages is the time delay (in seconds) between the first and second
compressors engaging. Lead-Lag governs whether the stages will reverse operation
order after some period of time designated by the Lead-Lag Time setting (Factory
Default: YES, 100hrs.). The Lead-Lag Time is the duration of time the unit will operate
before reversing the DX staging. In other words, based on the factory default,
Compressor 1 will engage before Compressor 2 for 100 hours of operation. After 100
hours, the order reverses and Compressor 2 will engage first. This cycle will continue
indefinitely.
Stage1:ON@050%OFF00%
Stage2:ON@100%OFF50%
T
HIS
SCREEN
SHOWS
WHEN
EACH
COMPRESSOR
IN
A
SINGLE
OR
TWO
STAGE
DX
UNIT
WILL
ENGAGE
AND
DISENGAGE
.
This screen only appears if DX cooling was provided with the unit.
Each compressor will engage and disengage based upon the percentage of
cooling that the user inputs (refer to Cooling Loop Override screen on the ‘MANUAL
OVERRIDE’ menu).
Lead-Lag Note
Stage:12
Compressor
Lead:12
Compress
Lag:21
T
HIS
SCREEN
ALLOWS
FOR
ADJUSTMENTS
TO
BE
MADE
TO
THE
ORDER
OF
WHICH
COMPRESSORS
WILL
ENGAGE
.
This screen only appears if 2-stage DX cooling was provided with the unit.
This screen shows the order in which the compressors will engage when operating in
the lead-lag setup.
Compressor will lockout if
safety switches (ID8) trip
3 times in:120 min
I
F
THE
CONTROLLER
DETECTS
THREE
(3)
ALARMS
IN
THE
TIME
PERIOD
SHOWN
,
IT
WILL
SHUT
OFF
THE
COMPRESSORS
AS
A
SAFETY
MEASURE
.
This screen only appears if DX cooling was provided with the unit.
The safety lockout screen monitors the safety loop of the DX system, including high
limit, low limit, and ambient temps. If the controller detects three (3) trips within 120
minutes, the controller will shut down the DX system. (Example: If the low limit switch
trips, automatically resets, and then trips two more times within 120 minutes, the DX
system will shut down). If there is a fatal trip, such as a high limit pressure switch trip,
the DX system will not run and the controller will signal an alarm after trying three times
unsucessfully to start the DX cooling process.
Heater Controller
Integration:300s
Band:20ºF
T
HIS
SCREEN
DISPLAYS
THE
INTEGRATION
TIME
FOR
THE
PI
CONTROL
OF
THE
HEATING
MODE
AND
THE
TEMPERATURE
BAND
AROUND
THE
S
UPPLY
SET
POINT
.
This screen only appears if a Heating option was provided with the unit.
This controller uses a Proportional + Integral type control. The integration time
programmed into the controller is to provide a smooth reaction to conditions, allowing
for less sporadic changes in discharge temperature. To speed up reaction time,
decrease the integration time. For slower reaction time, increase the integration time.
When making adjustments, make them in small increments, and test the system to
determine if the new setting is adequate prior to further adjustment. The band is the
range that the integration will occur between.
Range of Integration = Supply set pt ± Band. ie: 50° F ± 20° F
PROGRAM MENU - continued