NBE Brawn mixer BTO Series, Operation And Maintenance Manual

Page: 11 / 40

BTO-S
ERIES
O
PERATION
& M
AINTENANCE
M
ANUAL
12838 Stainless Drive, Holland, MI 49424 Phone: 616/399-5600 Fax 616/399-3084
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Copyright 2018 BRAWN Mixer www.BRAWNMIXER.com Page 5 of 9
11/27/2018
ELECTRIC MOTORS, Cont.
2. If possible, remove external load (disconnect drive)
and turn shaft by hand to ensure free rotation. This
may have been done during the installation
procedure; if so, and conditions have not changed,
this check may not be necessary.
a. If drive is disconnected, run motor at no load
long enough to be certain that no unusual
conditions develop. Listen and feel for
excessive noise, vibration, clicking, or
pounding. If present, stop motor immediately.
Investigate the cause and correct before
putting motor in service.
b. If drive is not disconnected, interrupt the
starting cycle after motor has accelerated to
low speed. Carefully observe for unusual
conditions as motor coasts to a stop.
3. When checks are satisfactory, operate at minimum
load and look for unusual conditions. Increase load
slowly to maximum. Check unit for satisfactory
operation.
CAUTION
Guard against overloading. Overloading causes
overheating and overheating means shortened insulation
life. A motor subjected to a 10°C temperature rise above
the maximum limit for the insulation may cause the
insulation life to be reduced by 50%. To avoid
overloading, be sure motor current does not exceed
nameplate current when nameplate voltage is applied
.
Electric motors operating under normal conditions
become quite warm. Although some places may feel hot
to the touch, the unit may be operational within limits.
Use a thermocouple to measure winding temperature.
The total temperature, not the temperature rise, is the
measure of safe operation. Investigate the operating
conditions if the total temperature measured by a
thermocouple placed on the windings exceeds:
230°F (110°C) for class “B” insulation
275°F (135°C) for class “F” insulation
302°F (150°C) for class “H” insulation
VOLTAGE REGULATION
Motors will operate successfully under the following
conditions of voltage and frequency variation, but not
necessarily in accordance with the standard established
for operation under rated conditions:
1. When the variation in voltage does not exceed
10% above or below normal, with all phases
balanced.
2. When the variation in frequency does not exceed
5% above or below normal.
3. When the sum of the voltage and frequency of the
voltage does not exceed 10% above or below
normal (provided the frequency variation does not
exceed 5%).
MAINTENANCE
Failure to properly maintain the equipment can result in
severe personal injury and product failure. The
instructions contained herein should be carefully
reviewed, understood and followed. The following
maintenance procedures should be performed regularly:
1. Bearing lubrication
2. Insulation resistance check
3. Cleaning
This checklist does not represent an exhaustive survey
of maintenance steps necessary to ensure safe
operation of the equipment. Particular applications may
require further procedures.
Dangerous voltages are present in the equipment which
can cause severe personal injury and product failure.
Always de-energize and ground the equipment before
maintenance. Maintenance should be performed only by
qualified personnel.
The use of unauthorized parts in the repair of the
equipment, tampering by unqualified personnel, or
removal or alteration of guards or conduit covers will
result in dangerous conditions which can cause severe
personal injury or equipment damage. Follow all safety
instructions contained herein.