Kongskilde TRL 20 Manual page 7

The TRL 20-100 blowers are equipped with different intake
components:
Never use quick release clamps on the blower inlet or
outlet, see section "Warning notes".
TRL 20 & 40 (TRL 30 & 50 at 60Hz) - Intake net and
bolt clamps
TRL 55 (TRL100 at 60Hz) - Intake net , regulation
throttle and bolt clamp
TRL 75 - Intake net, aperture and bolt clamps
For TRL75 applies:
If the blower is used for purposes where there is a low
back pressure, e.g. drying of grain, the air capacity may
be so large that the motor protection relay switches off
due to motor overload.
If this is the case, mount the ring supplied in the pres-
sure side of the blower, as illustrated on the
drawing.
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