Diagnostic: Compressor X Contactor Failure; Diagnostics - Low Pressure Cutout; Diagnostic: Circuit X Lpc Trip; Diagnostic: Circuit X Lpc Lockout - Trane Symbio 700 Application Manual

D D i i a a g g n n o o s s t t i i c c s s
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Diagnostic: Compressor X Contactor Failure

If a compressor proving input becomes Active for 5 continuous seconds when the associated
compressor command output is Inactive, a Diagnostic: Compressor X Contactor Failure is
generated and the following occurs:
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The "Compressor X Contactor Failure" diagnostic point is activated and the alarm output is
activated.
Diagnostics – Low Pressure Cutout
The following operation is enforced based on the state of the circuit's LPC input:
P P r r i i o o r r t t o o C C o o m m p p r r e e s s s s o o r r S S t t a a r r t t u u p p : :
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A A f f t t e e r r C C o o m m p p r r e e s s s s o o r r S S t t a a r r t t u u p p : :
An LPC Bypass Delay function delays the setting of a low pressure cutout after compressor
startup on a circuit until a pre-determined amount of time passes in low ambient conditions. The
length of the delay is determined based on ambient temperature:
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There are two diagnostics that can be generated based on the Compressor Low Pressure Cutout
input:

Diagnostic: Circuit X LPC Trip

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After the 3 minute low pressure event timeout has expired, if the unit is not under a lockout
event,
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On Heat Pumps, if the Outdoor Air Temperature is less than 0° F or if the unit is in active defrost,
the low pressure cutout input state is ignored.

Diagnostic: Circuit X LPC Lockout

If a circuit's LPC trip counter accumulates 4 low pressure events without the circuit running for
the 3 minute minimum on time (counter is not reset), a Diagnostic: Circuit X LPC Lockout" is
generated.
Once a Diagnostic: Circuit X LPC Lockout has been generated, the following occurs:
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The "Diagnostic: Compressor X Proving Lockout" diagnostic point is activated and the alarm
output is activated.
All compressors on the associated circuit are de-energized immediately and they are locked
out until a Reset Diagnostic is initiated.
If a compressor output is Off and its circuit's LPC input is open, compressor operation is not
inhibited, and the D D i i a a g g n n o o s s t t i i c c : : C C i i r r c c u u i i t t X X L L P P C C T T r r i i p p point will not be annunciated.
If the Outdoor Air Temperature Active is less than 40°F, the LPC Bypass Delay is set to 60
seconds
If the Outdoor Air Temperature Active is between 40°F and 50°F, the LPC Bypass Delay is set
to 30 seconds
If the Outdoor Air Temperature Active is greater than 50°F, the LPC Bypass Delay is 0 seconds
All Compressors Outputs on the effected circuit are commanded OFF
The Diagnostic: Circuit X LPC Trip point is annunciated
The circuit is disabled for 3 minutes
The circuit's LPC trip counter is incremented
The Diagnostic: Circuit X LPC Trip point is reset
If the stage is still requested ON, the circuit is allowed to stage again
If the Circuit runs for 3 minutes, its LPC Trip Count is reset to 0.
All compressors on the associated circuit are de-energized immediately and they are locked
out until a Reset Diagnostic is initiated.
The Diagnostic: Circuit X LPC Lockout point is activated and the alarm output is activated.
ACC-APG001A-EN