IOM / Rooftop Smart and Linéa™ Range - Page 29
COMMISSIONING
This work must only be carried out by a trained
refrigeration engineer
Before connecting to the power
- Ensure that the power supply between the building and
the unit meets local authority standards and that the cable
specification satisfies the start-up and operating condi-
tions.
- Ensure that the electrical connections in the control pa-
nel and on the motors are secure.
- Ensure that all drive motors are secure.
- Ensure that the adjustable pulley blocks are secure and
that the belt is tensioned with the transmission correctly
aligned.
- Using the electrical wiring diagram, check the conformity
of the electrical safety devices (circuit breaker settings,
presence and rating of fuses).
At this point attach the manometers to the refrigerant circuit
Powering up the system with the isolating switch
- Check the direction of rotation of the fans. Refer to the
rotation arrows situated next to the coils or fans (NOTE:
unlike a coil, a fan rotating in the wrong direction may
fail).
- The fans' direction of rotation is checked during an end
of production test.
- If they turn in the opposite direction, disconnect the power
supply to the machine at the building's mains switch,
reverse two phases of the incoming supply to the ma-
chine and try again.
- If only one of the fans rotates in the wrong direction,
disconnect the power supply at the machine's isolating
switch and reverse two of the component initial phases
on the terminal within the electrical panel.
Using CLIMATIC
- Check the voltages recorded against the rated values,
in particular on the system supply fans.
- If the readings on the fans are outside the limits, this
indicates excessive air flow which will affect the
thermodynamic performance. Refer to the "Air Flow
Balancing" section.
Thermodynamic readings using manometers and
prevailing environmental conditions
- No rated values are given here. These depend on the
climatic conditions both outside and inside the building
during operation. However, an experienced refrigeration
engineer will be able to detect any abnormal machine
operation.
Safety Test
- "Clogged filter" detection test : vary the setpoint value
(KP02, setpoint 93) in respect to the air pressure varia-
ble value (KP02, variable16). Observe the response of
the CLIMATIC.
- Same procedure for detecting "Missing Filter" (setpoint
94) or "Air Flow Detection" (setpoint 92).
- (If fitted), check the smoke detection function.
- (If fitted), check the Firestat by pressing the test button.
- Disconnect the circuit breakers of the condenser fans
and check the high pressure cut-out points on different
refrigerant circuits.
Reverse Cycle Test
On reversible units this test is used to check the switching
of the 4-way valves. Start the reverse cycle with reference
to the cold or hot temperature setpoint data according to the
climatic conditions at the time of testing (setpoint 15 +
setpoint 16).
Your machine is now operational.
You can now proceed to the setting stage. See the "Control"
section.
Three Phase Scroll Compressor Voltage Phasing
Three phase scroll compressors must be phased
sequentially to ensure correct compressor and blower
rotation and operation. Compressor and blower are wired in
phase at the factory. Power wires are color coded as follows:
line 1-red, line 2-yellow, line 3-blue.
- Observe suction and discharge pressures and blower
rotation on unit start-up.
- Suction pressure must drop, discharge pressure must
rise, and blower rotation must match rotation marking. If
pressure differential is not observed or blower rotation
is not correct.
- Disconnect all remote electrical power supplies.
- Reverse any two field-installed wires connected to the
main isolator.
- Make sure the connections are tight. Discharge and
suction pressures should operate at their normal start-
up ranges.
Refrigerant Charge
WARNING : Do not exceed nameplate charge under any
condition.
This unit is factory charged and should require no further
adjustment. If the system requires charge, reclaim the
charge, evacuate the system, and add required nameplate
charge.
NOTE : System charging is not recommended below 15°C.
In temperatures below 15°C , the charge must be weighed
into the system.
Compressor Controls
See unit wiring diagram to determine which controls are used
on each unit.
High Pressure Switch
The compressor circuit is protected by a high pressure switch
which cuts out at 28,25 bar + 07, bar.
Low Pressure Switch
The compressor circuit is protected by a low pressure switch.
Switch cuts out at 1,72 bar and automatically resets at 3,79
bar.
Crankcase Heater
Compressors have belly band compressor oil heaters which
must be on 24 hours before running compressors. As soon
as power is connected the heaters are energised once power
is applied at main isolator .
Freeze/Sensors Protection
De-energise compressors when evaporator coil temperature
falls below its setpoint to prevent evaporator freeze-up, reset
when evaporator coil temperature reaches its secondary
setpoint.
NOTE : For setpoint values refer to Climatic section of this
document.
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