On the display
The control center shows SYS X CONTROL VOLTAGE as a system safety. X is the number of the affected system, so the display tells you which system the message is about. The manuals list this message in their system safeties (faults) tables.
What it means
The message alerts the operator that the 115V AC control voltage to one of the systems is missing; the manual names this safety the System Control Voltage Cutout Fault. The affected system faults and shuts down immediately when the 115V AC supply is lost. The safety will not shut down a system if the Unit Switch is OFF, because that electrically removes the 115V AC to all systems — it is only used to indicate a situation where a single system is missing the 115V AC.
Why it appears
- A system fuse that has been removed or is blown, which cuts the 115V AC supply to the affected system.
What to check
- Read the system number X in the message to identify the system that is missing its 115V AC control voltage.
- Check whether the fuse for that system has been removed or blown; the manuals give this as the cause of the lost 115V AC supply.
Reset and restart
This safety does not cause a lockout. The system fault resets automatically when power is returned — that is, when the 115V AC supply to the affected system is back — and the system restarts once the fault clears.
Questions engineers ask
What does SYS X CONTROL VOLTAGE mean on a YORK YCAV chiller?
It alerts the operator that the 115V AC control voltage to one of the systems is missing. The affected system faults and shuts down immediately when the 115V AC supply is lost.
What causes the SYS X CONTROL VOLTAGE fault?
The manuals give a system fuse that has been removed or blown as the cause, which cuts the 115V AC supply to that one system.
Does SYS X CONTROL VOLTAGE lock out the chiller?
No. The safety does not cause a lockout; the system fault resets automatically when power is returned, and the system restarts once the fault clears.
Why does the message only concern one system?
The safety is only used to indicate a situation where a single system is missing the 115V AC. It does not shut down a system when the Unit Switch is OFF, because that electrically removes the 115V AC to all systems.
The same message on other models
Source
Written from the manufacturer's manuals for the YORK YCAV; every number and designation on this page is checked against them before publication. The row of the manual this message comes from:
All YORK YCAV messages: fault codes · YORK YCAV documentation · YORK manuals