On the display
The OptiView panel shows MBC - DSP COMMUNICATION. The manuals classify the message as a Safety Shutdown, and both print it in this single form.
What it means
This Safety Shutdown sets when the control board of the MBC detects a communication breakdown between the circuit boards inside the MBC. The second manual for the model words the same trigger as a communication error inside the control board itself.
When the fault sets, the MBC's ESD Fault contacts open — the other manual speaks only of the MBC Fault contacts. While the shutdown is active, the MBC holds Levitation mode and keeps the motor shaft levitated. The shaft leaves this state when the MBC receives a de-levitate command over serial communications, or when the VSD DC buss power is depleted.
Why it appears
- A communication failure between the circuit boards of the MBC, detected by the MBC control board — one manual describes the same fault as an error inside the control board itself.
Reset and restart
The shutdown is released once the communication failure at board level has been fixed. Only after the condition is released does pressing the CLEAR FAULTS button on the OptiView panel allow the chiller to be started.
Questions engineers ask
What does MBC - DSP COMMUNICATION mean on a YORK YMC2?
It is a Safety Shutdown: the MBC control board has detected a communication breakdown between the circuit boards inside the MBC. The MBC's ESD Fault contacts open when it sets.
Why is the motor shaft still levitated after this fault?
The MBC holds Levitation mode with the shaft levitated until it receives a de-levitate command over serial communications, or until the VSD DC buss power is depleted.
How do I restart the chiller after MBC - DSP COMMUNICATION?
The shutdown is released once the communication failure at board level has been fixed. After that, pressing the CLEAR FAULTS button on the OptiView panel lets the chiller be started.
Does this fault open any contacts?
Yes. The MBC's ESD Fault contacts open; the second manual words it as the MBC Fault contacts opening.
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