On the display
The panel shows MBC - CUSTOMER SERIAL LINK DISABLED. The manuals list this message among the Safety Shutdown messages of the chiller. While the message is active the chiller cannot be started; a start is possible again only once the MBC setting has been corrected and the shutdown has been cleared on the panel.
What it means
The panel sets this Safety Shutdown when the MBC does not report back that it is set for panel control. The command through which the MBC tells the panel its control state is not reported as panel control, so the chiller is held from a start. Behind the message sits the MBC's serial link: the panel expects it at Customer Serial Link, and the trip means it is no longer there.
Why it appears
- The MBC was reached from a computer running diagnostic software, and in the software's Remote Command tab the serial communication setting was moved off Customer Serial Link onto another choice.
What to check
- Connect a computer with the diagnostic software to the MBC and set the serial communication setting back to Customer Serial Link; the manual gives the procedure in Form 160.78-M1.
- Press the CLEAR FAULTS button on the panel.
- Start the chiller.
Setpoints and thresholds
- The MBC serial communication setting must stay at Customer Serial Link; the shutdown is set once it is changed to another choice.
- The MBC has to report back to the panel that it is set for panel control; the shutdown is set whenever that report shows anything else.
Reset and restart
The shutdown is cleared with the CLEAR FAULTS button on the panel once the MBC setting has been corrected. The chiller can be started when the MBC setting is restored to Customer Serial Link using the diagnostic software according to Form 160.78-M1 and the OptiView panel CLEAR FAULTS button is pressed.
Questions engineers ask
What does MBC - CUSTOMER SERIAL LINK DISABLED mean on a YORK YMC2?
It is a Safety Shutdown: the MBC is not reporting to the panel that it is set for panel control, so the panel holds the chiller from starting.
Why did the customer serial link get disabled?
The manuals give one cause: the MBC was reached from a computer with diagnostic software and, in the Remote Command tab, its serial communication setting was moved off Customer Serial Link onto another choice.
How do I clear MBC - CUSTOMER SERIAL LINK DISABLED?
Set the MBC serial communication setting back to Customer Serial Link with the diagnostic software — Form 160.78-M1 covers the procedure — and then press the CLEAR FAULTS button on the panel. The chiller can then be started.
Where is the setting behind this message?
In the diagnostic software that reaches the MBC: the manual places it in the Remote Command tab, where Customer Serial Link is one of the selectable choices.
Messages next to this one
Source
Written from the manufacturer's manuals for the YORK YMC2; every number and designation on this page is checked against them before publication. The row of the manual this message comes from:
All YORK YMC2 messages: fault codes · YORK YMC2 documentation · YORK manuals