Lennox FLEXY II Series

IOM – FLEXY II – 1007 – E Page 85
OPERATION MODE EXPLANATION
 Protection is activ ated when Scroll Discharge
Port. Reaches 150°C
(+/- 17K)
 Compressor is protected as « Unloaded » but
continues to run
 Protection mode balances
discharge/suction pressure
- Mot or heat builds ins ide
compressor
- No refrigerant flow to carry
motor heat away
 Motor protect or opens (Klyxon)
 Compressor turns off, cools
 Motor protect or resets , c om pressor res t arts
 Bi-metal disk resets bef ore motor
protection
 Cy c le will c ontinue unt il c ause of
ov erheat is fixed
SERVICE A COMPRE SS OR
 What to do?
 If a prot ec t ed c om press or is ident if ied
- Stop the compressor
- Allow to cool thoroughly
- Restart pump & check for
normal operation
 DO NOT ASSUME A COMPRESSOR RUNNING
UNLOADED (BALANCE PRESSURE) IS A
FAILURE
 Likely situations where protection may activate :
 Initial system charging (or recharging after
servicing)
- Compressor is run with too little
sy stem c harge
 Very common on split
sy stem
 Will result in v ery low
suction pressures (<1.7
Bars)
 Do not disable low
pressure cutouts while
charging
 Charge high-side with
liquid f irst
 Field servicing (system problem causes
ov erheating)
- Tec hnic ian will obs erv e
« Balanced pressures »
- Risk of misdiagnosis as failed
compressor
- Mus t st op pum p, c ool
thoroughly , reset
A
DVANCED
S
CROLL
T
EM PERATURE
P
RO TECTIO N
(ASTP)
Temp eratu r e B eh avio r wi th ASTP Pr o tectio n
40
65
90
120
150
180
0 20 40 60 80 100 120 140 160
Time (Minutes)
Temperature (°C)
DISC OPENS,
SCROLLS UNLOAD
C
ompressor Runs
Balanced
Pres sures
PROTECTOR RESETS ,
PUMP RESTARTS FULLY
LOADED
MOTOR PROTECTOR
OPENS, PUMP TURNS
OFF
Discharge
Port
Klyxon
ASTP
Compressor
off