Johnson Controls YORK YMC2 Operation And Maintenance Manual

Table 93: Status messages
Message Description
SOFT SHUTDOWN
The chiller is performing a Soft Shutdown. Simultaneously, the Hot Gas
Bypass Valve is commanded to 100% open (if Hot Gas Bypass is enabled),
the compressor VGD commanded to close rapidly. The motor drive speed
is slowed from its initial speed to the minimum required to prevent
surge. Then the motor drive speed is ramped to 0 Hz. The chiller then
transitions to coastdown. Soft Shutdown is initiated by the following:
• Leaving Chilled Liquid – Low Temperature
• Local Panel Stop Key
• Remote Stop
• Any MBC Fault occurs
• Multi-Unit Cycling – Contacts Open
• System Cycling – Contacts Open
• Control Panel – Schedule
• Condenser – Flow Switch Open fault active
• Chilled Liquid – Flow Switch Open fault active
• Expansion I/O – Serial Communications fault active
If the local panel safety stop switch is pressed or any chiller shutdown
faults other than those listed above occur, Soft Shutdown is immediately
terminated and a System Coastdown will occur.
START INHIBIT
The chiller is prevented from being started due to the reason displayed
on the details line of the status bar.
SYSTEM COASTDOWN
The chiller has shut down and removed the run signal from the motor
variable speed drive (VSD). The system is waiting for confirmation that
the driveline has stopped rotating. When the MBC and VSD report drive
frequency of 0 Hz for 5 s, coastdown is considered completed. Then, after
60 s delay the VSD Precharge command is released.
SYSTEM READY TO
START
The chiller is shut down but will initiate start upon receipt of a Local or
Remote start signal. The Magnetic Bearing Controller (MBC) does not
have the driveline rotor levitated. The Hot Gas Bypass Valve position (if
present) is set to the programmed Hot Gas Startup Position. The Level
Control Valve position is set to the programmed Condenser Level Control
Valve Startup Position. The VGD driven to the programmed VGD Startup
Position.
SYSTEM RUN
The chiller is running under the condition described in the details line of
the status bar.
SYSTEM STOPPED The chiller is shutdown with a prevailing stop command.
95
YMC
2
Mod B with OptiView Control Center

Johnson Controls YORK YMC2 Specifications

General

Brand	Johnson Controls
Model	YORK YMC2
Category	Chiller
Language	English