Start-Up; Preliminary Checks; Actual Start-Up; Operation Of Two Units In Master/Slave Mode (Option 58) - Carrier AquaSnap 61WG Series Installation, Operation And Maintenance Instructions

17 - START-UP

17.1 - Preliminary checks

- Never be tempted to start the unit without reading fully, and
understanding, the operating instructions and without having
carried out the following pre-start checks:
- Check the chilled water circulation pump operation with the
Quick Test function.
- Check the air handling units and all other equipment
connected to the evaporator. Refer to the manufacturer's
instructions.
- Check the condensing loop water circulation pump operation
with the Quick Test function.
- For units without hydraulic module, the water pump overheat
protection devices must be connected in series with the pump
contactor power supply.
- Ensure that there are no refrigerant leaks.
- Confirm that all pipe securing bands are tight.
- Confirm the the electrical connections are secure.
- Avoid a long common power wiring connection run inside the
unit close to the control or signal wiring.
- Observe the clearances on each unit side to facilitate
maintenance.
- The unit pipings are not 100% insulated whatever the options.
The insulation only protects against running condensation.
- To ensure that no condensate can run under the unit, a
condensate pan must be added under the unit that collects
100% of the condensate.
- If work is required in a control box or on the compressor
wiring, the phase order must be verified with a quick test
(refer to the TouchPilot Junior Control manual. The
compressors cannot support prolonged operation (>30
seconds) with reversed phases.
- Ensure that the last refrigerant charge made by the service
team corresponds with the charge given on the name plate
- otherwise the operating ranges and the unit efficiency will
be impaired. The required tolerance for the charge is ±2%.
- Do not interchange material with another unit. The elements
used for this unit are specific to this unit. Use the specific
manufacturer component list when ordering any parts.
- Before start-up ensure that the unit is level (1.5 mm/m).
- Check the operation of the fans in the air-cooled condensers.

17.2 - Actual start-up

IMPORTANT
- Commissioning and start-up of the unit must be
supervised by a qualified refrigeration engineer.
- Start-up and operating tests must be carried out with a
thermal load applied and water circulating in the
evaporator and condenser.
- All set-point adjustments and control tests must be
carried out before the unit is started up.
Ensure that all safety devices are operational, especially that
the high pressure switches are switched on and that the
alarms are acknowledged.
17.3 - Operation of two units in master/slave
mode (option 58)
The control of a master/slave assembly is in the entering water
piping (system return). All parameters, required for the master/
slave function must be configured using the Service Configuration
menu.
All remote controls of the master/slave assembly (start/stop, set
point, load shedding etc.) are controlled by the unit configured as
master and must only be applied to the master unit.
IMPORTANT: To permit master/slave operation both units
must be equipped with option 58.
Depending on the installation and control type, each unit can
control its own water pump.

17.4 - Parallel or serial connection of two units

Entering water control for a hydraulic module
1
See legend in the next column.
Leaving water control
1
See legend in the next column.
Legend
B
Master unit
C
Slave unit
Additional CCN board (one per unit, with connection via communication bus)
Control boxes of the master and slave units
Water inlet (for customers with both units)
Water outlet (for customers with both units)
Water pumps for each unit (included as standard for units with hydraulic
module)
Additional sensors for leaving water control, to be connected to channel 1 of
the slave boards of each master and slave unit
CCN communication bus
Connection of two additional sensors
2
2
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