Lennox BAC020SNM, Installation, Operating And Maintenance, Page: 123 / 137

MAINTENANCE PLAN
BALTIC R410A-IOM-0708-E Page 122
Task Operating mode
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Clean or replace filters: Disposable,
or metal frame.
Replace filters with new ones if disposable.
Vacuum clean or blow the dirt. Wash and dry
carefully. Replace media if necessary
Blocked filter will reduce the performance of the
unit.
THE UNIT MUST NOT OPERATE WITHOUT
FILTERS
o 20
Visual check of the oil level
Visually check the oil level through the sight
glass on the side of the compressor casing
o 2
Position check of the compressor
crankcase heater. Check the heating resistance is fitted properly
and tight around the compressor body.
o 2
Belt tension check. Pulley tightness
check. Check belt tension (Info in IOM) Replace belt if
necessary. Check Pulley fixing screw tightness.
o 10
Centrifugal fan bearings check
Isolate unit from the main power supply; Push
the fan wheel manually and check for abnormal
noises. Bearings are lubricated for life but may
need replacement after 10000 hours
o 10
Check absorbed Amps
Check absorbed Amps on all three phases;
compare with the nominal value given in the
electrical wiring diagram.
[] 15
Check Smoke detector
Start the unit. Trigger the smoke detector by
moving a magnet around the detector head.
Reset unit and control.
[] 5
Check Climatic control, set-points
and variables Refer to the commissioning sheet; Check all set
points are set according to this document.
[] 15
Check clock settings Check the time and date of the control o 5
Check the position and tightness of
refrigeration components
Check systematically all connections and fixings
on the refrigeration circuit. Check for oil traces,
eventually a leak test should be conducted.
Check operating pressures correspond to the
ones indicated on the commissioning sheet
[] 30
Check Airflow rate safety switch (if
fitted). Shut down supply fan. The fault must be
detected within 5 seconds.
o
Check freeze protection on HWC [] 5
Check three way valve on HWC
Increase room set-point 10°C above the actual
room temperature. Check operation of the
piston. It must move away from the valve head.
Reset the control.
[] 5
Check economiser actuator
operation
Check all fixings and transmission. Stop the unit
using the control. The fresh air damper must
close. Start the unit the fresh air damper should
open
[] 5
Check refrigeration 4way valve
With the unit running in cooling mode increase
the room set-point temperature by 10°C. The
unit should switch to heat pump mode. Reset the
control.
[] 5
Check tightness of all electrical
connections
Power down the unit and check and tighten all
screws, terminal and electric connections, taking
a particular attention to the power lines and low
voltage control wires
O 30
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:
29bar (+1 / -0) auto-reset 22bar (+ - 0.7)
Reconnect fans. Switch off the centrifugal supply
fan and wait for the LP switch to cut out: 0.5bar
(+ - 0.5) reset 1.5bar (+-0.5).
[] 15