Economizer / Compressor Operation; Economizer Pi Loop (Proportional And Integral); Economizer Loading - York ECO2 YPAL 050 Installation & Operation Manual

•
When the space temperature is equal to or greater
than 2.0° F above the "VAV SUPPLY AIR TEMP
RESET SETPOINT" the Simplicity Control will
use the "VAV COOLING SUPPLY AIR TEMP
LOWER SETPOINT".

Economizer / Compressor Operation

The Simplicity Control will use outdoor air without
compressor operation when the following is true:
•
Economizer is active.
•
The outdoor air temperature is equal to or less
then the economizer set point.
The Simplicity Control will use outdoor air with
compressor operation when the following is true:
•
Economizer is active.
•
The outdoor air temperature is above the econo-
mizer set point.
When outdoor air and compressor operation is available
the compressors operation will be controlled as
follows:
•
If the supply air temperature is 5.1° F or more
above the economizer set point and the Econo-
mizer PI output is saturated (100%) the Simplic-
ity Control will turn on a compressor and start a
3 minute timer.
•
If after 3-minutes the temperature is still 5.1° F
above the economizer set point and the Econo-
mizer PI output is saturated (100%) the Simplic-
ity Control will bring on a second compressor and
start a three minute timer.
•
This sequence would continue until all the com-
pressors on.
•
If after the 3-minute timing the supply air tem-
perature is within +/- 5.0° F of the economizer
set point no change will be made to the number
of compressors operating.
•
If after the 3-minute timing the supply air tem-
perature is 5.1° F or more below the economizer
set point and the Economizer PI output is low
(dampers at the minimum position setting) the
Simplicity Control will turn off a compressor.
JOHNSON CONTROLS
•
As long as the supply air temperature is 5.1° F
below the economizer set point and the Econo-
mizer PI output is low (damper at minimum
position setting) the Simplicity Control will turn
off compressors every 3-minutes until all the
compressor have been turned off.

Economizer PI Loop (Proportional and Integral)

The Simplicity Control uses a proportional and integral
logic (PI loop) to control the operation of the damper
actuator. The Simplicity Control monitors the change
in the supply air temperature to the economizer set point
verses changes to the output to the damper actuator.
When the supply air temperature is more then 2.0° F
from the economizer set point the Simplicity Control
will change the output to the economizer damper 1%
every 2 seconds. If the supply air temperature is within
+/- 2.0° F of the economizer set point the Simplicity
Control will change the output to the economizer
damper 0.5% every 2 seconds.

ECONOMIZER LOADING

Economizer Loading is a programmable option that
can be used to place an artifi cial load on the unit to
prevent cycling a compressor off when the supply
air temperature approaches the "SUPPLY AIR TEMP
LIMIT COOLING SETPOINT".
T h e f o l l o w i n g S y s t e m P a r a m e t e r m u s t b e
programmed:
"ECONOMIZER LOADING ENABLE" – must be
enabled under the COOLING SETUP tab in the
Simplicity PC software package.
"SUPPLY AIR TEMP LIMIT COOLING SETPOINT"
must be programmed using the COOLING SETUP tab
in the Simplicity PC software package.
"SUPPLY AIR TEMP LIMIT FOR COOLING" must
be enabled using the COOLING SETUP tab in the
Simplicity PC software package.
FORM 100.50-NOM6 (1207)
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