Rockwell Automation 1302 575v AC Drive - Canada Only - Manual (Page 27)

3–9 1302 Preinstallation
Publication 1302-5.0 — January, 1998
The required external hardwired emergency stop must be either a
category 0 or 1 stop, depending on the user’s risk assessment of the
associated machinery. In order to fully comply with machinery
safety standard EN 60204-1:1992, part 9.2.5.4, at least one of the
two stop methods must be a category 0 stop.
To obtain motor nameplate horsepower, the Drive’s output current
rating at the selected carrier frequency should be equal to or greater
than motor nameplate current. If the motor nameplate current rating
is higher than the Drive’s output current rating, derate motor
horsepower by the ratio of the Drive’s output ampere rating (at the
selected carrier frequency) to the motor nameplate current. Note that
this approximation is only accurate if the Drive and the motor have
nearly the same rating.
Single Motor Applications
Size the drive and motor for the load and speed requirements of the
specific application.
The motor’s operating current must not exceed the drive’s rated
output current (at the selected carrier frequency). In addition, the
motor’s horsepower rating (for example, 1, 2, 3, 5, 7, 10 HP) must
not be more than one horsepower range larger than the Drive’s
horsepower rating.
If the motor will be operated below one-half of its rated speed, the
motor overload relay may not protect the motor because of reduced
cooling action due to the reduced speed. A motor thermostat,
internal to the motor, should be installed to monitor the actual
temperature of the windings.
Multiple – Motor Applications
One Drive can run two or more motors. Adhere to the following
requirements to assure correct Drive operation in this case:
•
When starting and stopping all the motors at the same time (using
the Drive for starting and stopping), the sum of the full-load sine
wave currents of all the motors must be equal to or less than the
maximum sine wave output current at the selected carrier
frequency for the Drive.
For example: I
FLA
+ I
FLA
+ I
FLA
= I
TLA
(Motor 1) (Motor 2) (Motor 3) (Total Load)
Where: I
TLA
<100% rated drive output at the selected carrier frequency
•
When one or more of the motors connected to the output of the
Drive are to start independently (using a secondary switching
device to add or remove the motor from the circuit):
Any motor that starts or stops while the Drive is running must
have a current rating less than 10% of the maximum sine wave
current rating of the Drive at the selected carrier frequency.
Motor Considerations