York MAXE OPTIVIEW YK Service Instructions Manual page 130

Smart Freeze Protection
The following is a summary of the operation with Smart
Freeze enabled and disabled:
SMART FREEZE DISABLED:
• Minimum Leaving Chilled Liquid Setpoint:
38.0ºF
• Low Chilled Liquid Temp cycling shutdown thresh-
old: 1º to 34.0ºF below the Leaving Chilled Liq uid
temp Setpoint, as programmed, or a minimum of
36.0ºF.
• Low Evaporator Pressure safety shutdown thresh-
old: R22 - 54.3 PSIG (29.6ºF); R134a – 25.0 PSIG
(28.7ºF)
• PRV Load Inhibit: R22 – 56.2 PSIG; R134a – 27.0
PSIG
Load Inhibit disable: R22 – 57.5 PSIG; R134a – 28.0
PSIG
SMART FREEZE ENABLED:
• Minimum Leaving Chilled Liquid Setpoint: 36.0ºF
• If the Leaving Chilled Liquid Temperature Setpoint
is >38.0ºF:
1. The Low Leaving Chilled Liquid Tem per a ture
Cy cling shutdown threshold: 1 to 34.0ºF below the
Leaving Chilled Liquid Tem per a ture Setpoint, as
programmed, or a minimum of 36.0ºF.
130
2. The Low Evaporator Pressure Safety shut down
threshold is the same as Smart Freeze Dis abled
above.
• If the Leaving Chilled Liquid Temperature Setpoint
is <38.0ºF:
1. The Low Leaving Chilled Liquid Tem per a ture
Cy cling shutdown threshold: 1 to 3.0ºF below the
Leaving Chilled Liquid Tem per a ture Setpoint, as
programmed, or a minimum of 34.0ºF.
2. Low Evaporator Pressure shutdown threshold:
Determined by how far the evaporator refrigerant
temperature is below the freeze threshold of 32.8ºF
(refrigerant temperature sensor RT7) or 34.0ºF
(Evap o ra tor Saturation Temperature. See Note 1
below.) and the to tal number of seconds it remains
there. Refer to ex pla na tion above.
• PRV Load Inhibit: same as Smart Freeze Dis abled
above.
• Load Inhibit Disable: same as Smart Freeze Dis-
able above.
Note 1: The freeze threshold evaporation saturation
tem per a ture is 32.0ºF on Flash Mem o ry Card ver sion
C.MLM.01.01 and ear li er.
FORM 160.54-M1(503)
YORK INTERNATIONAL