Sedgwick SM255t, Operation And Maintenance Instructions, Page: 27 / 32

SM255t Operation/Maintenance Instructions Page 27 of 32
10.2 Brake Motor Installation & Maintenance
Installation
It is the responsibility of the machine installer
to ensure that:
•
The brake functions correctly after final
installation.
•
Earthing has been carried out according to
local regulations before the connection to
the mains.
•
The supply of motor, rectifier/brake, and
auxiliary equipment (if any) has been made
using cables of suitable section to avoid
overheating and/or too high voltage drop.
•
In case of inverter supply the wiring
instructions of the inverter manufacturer
have been correctly followed for the motor
and a separate supply (directly from the
mains) has been provided for the
rectifier/brake.
Note: due to poor supply characteristics we do not recommend use with phase converters.
Maintenance
***Brake reliability & lifetime is dependent upon good periodic maintenance.
•
All maintenance work on brake motors should be carried out by qualified personnel, always
with the machine out of operation, disconnected and secured against starting.
•
Low-torque DC brake motors (with electromagnetic braking in case of supply failure) have a
fixed braking torque; it is not possible to adjust the stopping times of these motors.
If a brake motor is running excessively hot it is likely to be caused by the brake not releasing.
This is probably because of one of the factors below:
•
Brake airgap setting incorrect
•
Poor rectifier supply connection
•
Use with phase converter
•
Dust, wood chipping etc locking the
mechanism
•
Blown or damaged rectifier
•
Worn or damaged parts
Air-gap Adjustment
1. Tighten down the hexagon head bolt in the centre of the fan cover completely (without
forcing) then unscrew by one third of a turn (except for the TE/TESH motors which need
adjusting by one half of a turn). For a more accurate setting remove the fan cover & tighten
down the hexagon head bolt, again without forcing, then unscrew until the airgap (between
2.1 & 2.3) is between 0.3mm & 0.5mm.
2. We recommend the occasional use of an air jet to eliminate dust or other particles that
may have settled on the braking surface.
3. After several air-gap adjustments verify that the thickness of the friction surface is no less
than 1mm, if it is then replace the fan with an
original manufacturer’s part.