Johnson Controls York YKEP Series User Manual

FORM 160.77-O2
ISSUE DATE: 11/15/2011
JOHNSON CONTROLS
8
SECTION 1 - YKEP CHILLER OVERVIEW
Economizer Compressor Stop criteria:
Primary Compressor Calculated Flow ≤ the prescribed
Start criteria line minus 2000 CFM
3. When the primary compressor capacity reaches
full capacity dened by either 100% input cur-
rent FLA or fully open PRV and full speed (VSD
starter types), the economizer compressor switch-
es to Boost operating mode. In this mode, the
economizer compressor capacity is controlled
to maintain leaving chilled liquid temperature
at setpoint and the primary compressor is given
a leaving chilled liquid temperature target 1 de-
gree F below the chiller setpoint to keep it fully
loaded. The economizer compressor is then con-
trolled to maintain the chiller programmed leav-
ing chilled liquid temperature setpoint using its
PRV’s. As additional capacity is required, the
economizer compressor draws the economizer
pressure lower, increasing the refrigeration effect
PRIMARY COMPRESSOR
CONDENSER
ECONOMIZER COMPRESSOR
ECONOMIZER
EVAPORATOR
CHILLED
LIQUID
(OPTIONAL)
HOT GAS
BYPASS VALVE
ECONOMIZER
LEVEL VALVE
ECONOMIZER
LEVEL
SUBCOOLER
LEVEL
COOLING
LIQUID
PRV
VGD
VGD
CHECK
VALVE
PRV
SUBCOOLER
LEVEL VALVE
FIGURE 2 - YKEP CHILLER SYSTEM DIAGRAM
LD16021

Johnson Controls York YKEP Series Specifications

General

Brand	Johnson Controls
Model	York YKEP Series
Category	Chiller
Language	English