To Start-Up The Scf System - Carrier ChillerVu 23XRV Series Application Manual

To start-up the SCF system

With the chillers set for CCN control, set the start command in the SCF program by accessing the i-Vu® interface
and navigating to Properties > Control Program tab > Run Conditions > Chiller Manager Start (BBV, BNI, or BBI,
depending on your system). Select Start or On, as applicable.
The Equipment Run Status should change to On and, after a short delay, the lead machine should enable and
ramp up.
•
Assuming sufficient load, the lag machine starts when:
The lead machine exceeds 79% capacity (in Chiller Lead/Lag Control, the Load of lead chiller default
○
value)
The chilled water supply temperature is greater than the setpoint for 10 minutes
○
•
When the lag machine starts, Soft Starting logic allows both machines to ramp up together by calculating a
demand limit for each machine that will be gradually raised over time. The calculated demand limit is raised
by 10% every minute (configurable) until it reaches 100% and Soft Starting is no longer active.
•
Also, whenever both machines are operating, the upstream machine receives a calculated setpoint that is
higher than the downstream machine, which balances the load between the 2 machines.
•
If load is insufficient to run both machines, (capacity drops below 35%, or below the default lag chiller enable
load value minus 44% hysteresis), then only the lead machine operates.
•
When the load conditions increase sufficiently again, as stated above, the lag machine stages on.
Notes for optional functions
•
Lead Chiller Fault Handing – Assuming single chiller operation, the lag chiller stage should start if the lead
chiller faults
•
Chiller Rotation – Once you have observed stable operation, set Chiller rotation method to option 6 –
Runtime Equalize. Over time, the run hours of both machines should be roughly equal.
You should also test these functions, if applicable, in the following Properties > Control Program section:
•
Chiller Shutdowns – verify that the system correctly shuts down when receiving a refrigerant, emergency, or
plant shutdown signal
•
Demand Limiting – verify that the system demand limit correctly regulates chiller operation when a demand
limit signal is received over the network
Carrier® ChillerVu™
23XRV Series Counterflow Application Guide 8
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