Carrier 30RB-170R Installation, Operation And Maintenance Instructions page 73

12 - OPTIONS
Rules for a correct duct network
- E a c h d u c t m u s t s e r v e a m a x i m u m o f 2 f a n s –
DO NOT EXCEED this limit.
- In case of multiple fans in the same duct, they must belong
to the same refrigerant circuit and to the same V-shaped coil
system – DO NOT MIX refrigerant circuits or V-shaped coil
systems in the same duct.
IMPORTANT:
The duct connections on the units must not generate any
mechanical stress on the fan supporting structure.
The fan shrouds and the fan protection grilles must always
remain in their position inside the ducts.
Use bellows or flexible sleeves for the duct connection.
At the start of each duct, install an access hatch measuring
at least 700 x 700 mm to allow maintenance of fan components
(motor replacement, removal of impeller).
Fan motor electrical protection
In case of a locked rotor or an overload, the motors of each circuit
are electrically protected by the circuit variable speed drive.
Each drive follows a variable current characteristic, based on the
frequency from 10 to 60 Hz and the number of controlled fans.
If a fan stops working, the variable drive will automatically detect
the malfunction.
Refer to the control manual for the list of alarms specific to this
option.
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