NORD Drivesystems B1000 - Manual (Page 697)

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Engineering Information
Standard Design & Construction
MOTORS
G1000 – Subject to Change Without Notice
Ambient Temperature
NORD motors are designed to operate with a maxi-
mum ambient temperature of 40°C (104°F). If the
motor’s operating environment exceeds 40°C, the
motor’s nominal power P
n
either needs to be de-
rated (see table below) or use upgraded insulation.
Ambient temp [°F] 113 122 131 140
Ambient temp [°C] 45 50 55 60
De-rate factor 0.96 0.92 0.87 0.82
Motor Rated Power = [P
n
x De-rate factor]
Elevation
NORD motors are designed to operate at an elevation
of up to 3300 ft (1000 m) above sea level. At higher
elevations the air is thinner resulting in less cooling
capacity. If the motor’s nominal power P
n
installation
elevation exceeds 3300 ft (1000 m), the motor either
needs to be de-rated (see table below) or requires up-
graded insulation.
Altitude [ft] 5000 6500 8200 10000 11500 13000
Altitude [m] 1500 2000 2500 3000 3500 4000
De-rate Factor 0.97 0.94 0.90 0.86 0.83 0.80
Motor Rated Power = [P
n
x De-rate factor]
Service Factor
Motors rated 230/460V-60Hz and 332/575V-60Hz
have a service factor of 1.15. Almost all other
motors have a service factor of 1.1 or 1.0.
Starting Frequency
One major advantage of NORD motors & brakemo-
tors is the ability to operate in high start-stop appli-
cations. Due to the motors optimized design, NORD
motors can, under some conditions, cycle thousands
of times an hour. This means that a NORD brake-
motor can often be used to replace a clutch brake
system. If the motor or brakemotoris used with an
inverter or vector drive, the motor’s cycling capacity
can be increased even more.
The permissible frequency of switching may be
calculated as follows:
Z
O
no-loadstarting frequency [starts/hour]
Z
zul
permissible starting frequency[starts/hour]
J
mot
moment of inertia of motor [lb-in2]
J
red
external inertia refl ected to motor shaft [lb-in2]
T
a
required starting torque [lb-in]
T
l
load torque after starting [lb-in]
Z
zul
= Z
0
x
Duty Classes
The following duty types are defi ned in IEC 60034-1.
Power Increasing Factor for Short-term &
Intermittent Operation
Motor ratings in this catalog are based on contin-
uous duty operation (S1). If a motor is designed
for S1 duty, but is to be operated for short-time
or intermittent operation it can be subjected to
higher loads. The factors of “motor rated power”
increases versus nominal power (
P
n
) are included in
the following table.
Duty Type Explanation Excerpts
S1
Continuous operation at a constant load, the mo-
tor reaches thermal equilibrium
S2
Short-time operation at a constant load for a given
time followed by a time of rest until the motor is
completely cooled down to ambient temperature.
Example: S2-10 minutes
Recommended values for determination: 10, 30 minutes
S3
Intermittent operation sequential, identical run
and rest cycles with constant load. Temperature
equilibrium is never reached. Starting current has
little effect on temperature rise. The cyclic dura-
tion factor (cdf) indicates the portion of operation
time in relation to a complete duty cycle. The typi-
cal duty cycle time is 10 minutes, unless otherwise
specifi ed.
Example: S3-40%
Recommended values for determination: 25, 40, 60%
S6
Continuous operation with intermittent load se-
quential, identical cycles of running with constant
load and running with no load. No rest periods.
Example: S6-40%
Recommended values for determination: 25, 40, 60%
Duty Type Increasing
factor
S2 Operating time
10 min 1.40
30 min 1.15
S3 Cyclic duration factor (cdf)
25% 1.33
40% 1.18
60% 1.08
S6 Cyclic duration factor (cdf)
25% 1.45
40% 1.35
60% 1.15
Motor Rated Power = [P
n
x Increasing factor]
1 –
T
1
T
a
1 +
J
red
J
mot