Lennox ROOFTOP FLEXY FXK 55, Installation, Operating And Maintenance Manual

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MAINTENANCE PLAN
FLEXYII_WSHP-IOM-1307-E - 79 -
Task Operating mode
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Check HP/LP safety switches
Install manifold gauges on the circuit to be checked.
Shut down the axial fans and wait for the HP switch to
shut down the compressor : 29 bar (+1/-0) auto reset 22
bar (+/- 0,7).
Reconnect fans.
Switch off the centrifugal supply fan and wait for the LP
switch to cut out : 0,5 bar (+/- 0,5) reset 1,5 bar (+/- 0,5).
[] 15
Check outdoor fans and fan
guards Check the fan blades conditions and all fan guards and
protections.
O 5
Check position of all sensors
Check the good positioning and operation of all sensors.
Check the values given in the control system.
Replace sensor if necessary.
O 5
Check and clean if necessary all
fresh air grilles
Check the fresh air grilles (if fitted). If dirty or damaged,
remove from the unit and clean with high pressure water
cleaner.
Refit on unit once clean and dry.
O 5
Clean condensate drain, indoor
and outdoor coils (following local
regulations)
Visually check the coils for dirt. If not too dirty, cleaning
with a light brush may be enough (WARNING : fins and
copper tubes are very fragile ! Any damage WILL reduce
the performances of the unit). If very dirty, deep industrial
cleaning is required using de-greasing agents (external
contractors must be called).
O/[]
1 h if
cleaning.
Check electrical heater element
for excessive corrosion
Isolate the unit. Pull the electrical heater out of the heater
module box and check the resistances of traces of
corrosion.
Replace resistance as required.
O
1 h if
replace
ment
Check anti-vibration mountings,
for wear and tear
Visually check anti-vibration mountings on compressors
and centrifugal fan.
Replace if damaged.
O
1h if
replace
ment
Check refrigeration circuit for
traces of acid in the oil
Take a sample of oil from the refrigeration circuit. []
Check glycol concentration in the
hot water coil circuit
Check the glycol concentration in the pressurised water
circuit (a concentration of 30% gives a protection down to
approx. -15°C).
Check the circuit pressure
[] 30
Check defrost cycle with 4-way
valve inversion
Switch the unit to heat pump mode. Change the set point
to obtain the standard defrost mode and reduce the cycle
time to the minimum value.
Check the operation of the defrost cycle
[] 30
Gas burner module check for
corrosion Pull out the burner to access the tubes (refer to Gas
burner section in the installation manual)
[] 30
Sweeping and cleaning the gas
burner
Clean the in-shot burners and the blower wheel lightly
with a brush. Sweep the flue and flue box. Wipe-off the
dust from the housing of the motor. Clean combustion air
inlet louver.
Pull-out baffles from the tubes, sweep the tubes.
CHECK FLUE BOX GASKET.
[] 30
Gas supply
pressures/connections checks Refer to gas burner section in the installation manual for
details
[] 15
Gas regulation valve settings
Refer to gas burner section in the installation manual for
details
[] 30
Check gas burner safety switch
Refer to gas burner section in the installation manual for
details
[] 30
Check and clean water filter (only
for water cooled rooftop)
CAUTION : the water circuit may be pressurized.
Observe the usual precautions when depressurizing the
circuit before opening it. Failure to observe these rules
could lead to accidents and cause injury to service
personal.
[] 20