Elmo Rietschle F-REL - Manual (Page 18)

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Commissioning and decommissioning
6.2 Adjusting the capacity of RER/REL
To avoid overloading the motor during starting
please take note of the following:
a) Do not start the radial blower unless it is connected on the pressure or suction side.
b) If the air requirement of the system is variable e.g. through valves, taps or variables inlet and/or outlet
orifi ces then these should be set so that maximum capacity is utilised. During start up this condition
will result in the highest motor load.
c) The full load current as indicated on the nameplate of the blower motor determines the maximum avail-
able capacity of the blower.
When starting up the blower please check:
I) Whether the voltage and the frequency correspond to the data on the data plate?
II) Whether at peak load the full load current is exceeded?
d) Exceeding the full load current indicates (if the voltage and frequency are correct) that the blower has
been overloaded with regard to capacity.
In such a case the power should be adjusted by throttling. Throttling can be achieved without changing
the base unit itself as follows:
d.1) Insert a ring shaped orifi ce plate made of aluminium or steel between the connection fl ange of the
blower and the pipe or at any place in the pipe. Its outside diameter and fi xing holes should conform
with the size of the fl ange. However its inside diameter should be smaller than the effective diameter of
the fl ange.
Adjust the internal diameter so that the amperage does not exceed the full load current.
Or:
d.2) Insert an adjustable valve i.e. ball or butterfl y between the connection fl ange of the blower and the pipe
or at any place in the pipe and adjust it so that the running amps do not exceed the full load current.
It is advisable to clamp the valve in this position so that the setting cannot be altered unless by author-
ised personnel.
The points d.1 and d.2 can be omitted if it is possible to reduce the power to the design value by re-
ducing the suction and/or exhaust diameter or by increasing the fl ow resistance within the system.
e) Instead of adjusting the system to the existing blower, it is possible depending on the model of blower
and on the rating of the motor to use the same size blower but with a larger motor. For further advice
please contact your Rietschle representative.