York YD Series - Page 21

JOHNSON CONTROLS
21
SECTION 1 – DESCRIPTION OF SYSTEM AND FUNDAMENTALS OF OPERATION
FORM 160.69-O1
ISSUE DATE: 9/30/2012
1
Are Compressor
Motor Currents
Equal within 20%
Are vanes on the lower current
compressor open more than the
h
i
gh current compressor?
Chiller Running
Two Compressor Mode.
Lead Compressor controlling LChWT
Lag Compressor following current of
Lead
No
Yes
No
Yes
Close Compressor Pre-rotation Vane
Motors
No
Have # of Total Surge Counts
Exceeded the # allowed within
time period setting
Stop and Lockout the lag compressor
Provide screen warning
Yes
Anti-Surge Control Algorithm
User Programmable:
Number of Surge Counts Allowed
(Default 3, range 2 to 8)
Count Window time period
(Default 60 min, range 15 to 120)
Increment Total Surge Count
YD Dual Compressor Chiller
FIGURE 2 – CHILLER OPERATION FLOW CHART - (CONT'D)
LD10493