Figure 2 - Chiller Operation Flow Chart - York YD Series Operation Manual

FORM 160.69-O1
ISSUE DATE: 9/30/2012
Chiller Standby
Are
Compressor
Disch Valves
Closed?
Chiller Start
Requirement
Select Lead Compressor
Open Lead Compressor
Discharge Valve
Auto zero the 3
Oil Pressure Transducers
Pre Lube cycle
Lead Compressor
Is
Lead Compr
Disch Valve
Open?
Yes
Start Lead Compressor
(normal sequence)
Enable capacity controls logic.
Lead compressor PRVs
responding to LChWT

FIGURE 2 - CHILLER OPERATION FLOW CHART

JOHNSON CONTROLS
SECTION 1 – DESCRIPTION OF SYSTEM AND FUNDAMENTALS OF OPERATION
YD Dual Compressor Chiller
Start Inhibit
No
Is a Compressor in
Service Lockout
Select the other
Compressor
Normal Sequence
(Extended prelube switch applies
only to lead compressor)
> 40 seconds
No
Alarm/Fault
Electro-Mechanical Starter
Chiller Start Sequence
Yes
Select the Compressor
with Least Run Time
Chiller Run
Single Compressor
1
No
LD10487
15