Machine Protection
and Adaptive
Control
Current Limit Protection
Current Limit Protections exist to avoid motor current overload and damage to the compressor motor during starting and running.
Compressor motor current is continuously monitored and current is controlled via a limit function that to prevent running into over current diagnostic trips.
The current limit control logic attempts to prevent the motor from shutting down on a diagnostic trip by limiting compressor current draw relative to an adjustable current limit DynaView™ Current Limit Setpoint. This setpoint can also be lowered to provide electrical demand limiting on the unit as required. This could also be set to allow the Chiller to continue to run at a lower load to avoid tripping off via a diagnostic.
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The Current Limit function uses a PID algorithm (Similar to the Leaving Water Temperature control) that allows the chiller to run at the Current Limit Setpoint. At machine startup, or with any setpoint change the new current limit setpoint reached after the is filtered setpoint time elapses. The minimum current limit setpoint is default set to 40 percent RLA
The Current Limit Setpoint (CLS) can be changed from: Front Panel, External Analog input (with GBAS (external) option), or Tracer (Tracer option). However, If present Tracer current setpoint has the highest priority, unless disabled in the DynaView™ Setpoint source override menu. The External CLS has second priority, and will be used if Tracer is disabled or not installed. The Front Panel Setpoint has the lowest priority, and will be used if Tracer and the External CLS are both disabled.
Phase Loss Protection
Loss of phase detection protects the chiller motor from damage due to a
Reverse Rotation Protection
This function protects the compressor from being driven in the reverse direction. Incorrect phase rotation detection results in a manually resettable diagnostic. Phase Reversal protection is default to Enable, however can be disabled via the service tool.
