Carrier NDK33BN0KB, Operation & Service Manual

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62-61753-21 4-12
In both upshift calculations the upshift offset range is
limited to a maximum of 3 amps.
3. Fan Motor Delay
When ever any fan motor has been energized, there
will be a 3 second delay before Economized Operation
is allowed
4. Compressor Start
Before a compressor startup the system will be transi-
tioned to Bypass Mode. The system will remain in
Bypass Mode until a calculated time has expired and
the compressor suction modulating valve (CSMV) has
opened to a predetermined position. 5. Compression Ratio
The microprocessor monitors compressor operating
pressures and calculates a compression ratio. If, while
operating in Economized Mode, the calculated value
exceeds 21:1, operation will transition to Bypass
Mode. Economized Mode will not resume until the
compression ratio has fallen to 19:1.
6. Pulldown Operation
If in Start/Stop Operation and all conditions for an OFF
cycle have been met except for setpoint, operation will
be transitioned to the Economized Mode to pull down
to setpoint and cycle off quicker.

If in Continuous Operation with a setpoint in the
perishable range (above -12°C [+10.4°F]) and the
High Speed Pulldown Configuration is set to YES,
operation will be transitioned to the Economized
Mode until termination conditions have been met.