Installation and Maintenance Manual
GEI-M1031-B
12
IV. OPERATION (cont’d)
D. Initial Start
1. After inspecting the machine carefully, make the initial start by following the regular
sequence of starting operations in the control instructions.
2. At initial start, the rate of rise of the bearing temperature is more indicative of trouble
than total temperature. When starting a machine for the first time, the bearing
temperature should be observed for a minimum of two hours. If at any time the rate of
temperature rise exceeds 2C/minute, shut down the machine immediately and make
an investigation of lineup conditions, and if necessary, the bearing assembly.
3. Check motor operation under load for an initial period of at least one hour to observe
whether any unusual noise or hot spots develop.
4. In the event of excessive vibration or unusual noise, disconnect the machine from the
load and check the mounting and alignment.
5. Space heaters (when supplied) should be de-energized during motor operation.
6. Check the operating current against the nameplate value. Do not exceed the value of
nameplate amperes times service factor (if any) under steady continuous load.
208 Volt system: When a 230/460 Volt motor with a nameplate which states “usable at
200V, _Hp, _Amps, 1.0SF” is operated on a 208 Volt system, the motor slip will increase
approximately 30% and the motor locked-rotor, pull-up and breakdown torque values
will be reduced by approximately 20% to 30%. Therefore, it should be determined by the
user that the motor will start and accelerate the connected load without injurious
heating and that the breakdown torque is adequate for the application.
E. Jogging and Repeat Starts
F. Heating
Use a thermometer or thermocouple to determine temperature. If there is any doubt about
the safe operating temperature, take the temperature of the part in question and confer
with the nearest GE sales office. Give full details, including all nameplate information.
Overheating of the machine may be caused by improper ventilation, excessive ambient
temperature, dirty conditions, and excessive current due to overload or unbalanced a-c
voltage.
Repeated starts and/or jogs of induction motors greatly reduce the life of the
winding insulation. The heat produced by each acceleration or jog is much more
than dissipated by the motor under full load. If it is necessary to repeatedly start or
jog a motor, it is advisable to check the application with the local GE sales office.
Caution