Application Notes
13-3
605 Series Frequency Inverter
When the dc link voltage rises above 750V (400V build) or 385V (230V build), the brake unit
switches the external resistor network across the dc link. The brake unit switches off again when
the dc link voltage falls below the threshold level. The amount of energy produced by the motor
during regeneration depends upon the DECEL RATE parameter (refer to the SYSTEM RAMP
function block) and the inertia of the load.
Note:
The dynamic braking circuit is designed to cope with short term stopping or braking only.
It is not rated for a continuously overhauling load.
The Inverter is supplied without braking resistors. Below is a guide to calculating the braking
requirements of the system.
Brake Resistor Selection
Brake resistor assemblies must be rated to absorb both peak braking power during deceleration
and the average power over the complete cycle.
Peak braking power P
0 0055J
n
n
t
W
1
2
2
2
b
=
×
−
.
(
)
( )
pk
J
- total inertia (kgm
2
)
n
1
- initial speed (rpm)
Average braking power P
P
t
av
pk
c
=
x t
b
n
2
- final speed (rpm)
t
b
- braking time (s)
t
c
- cycle time (s)
Obtain information on the peak power rating and the average power rating of the resistors from
the resistor manufacturer. If this information is not available, a large safety margin must be
incorporated to ensure that the resistors are not overloaded.
Note:
Eurotherm Drives can supply suitable brake resistors.
By connecting these resistors in series and in parallel the braking capacity can be selected for the
application.
The minimum resistance of the combination should not be less than that specified in Chapter 11:
“Technical Specifications” - Power Details.
The resistor(s) must be specified to the maximum dc link voltage (800V for 400V build, 400V
for 230V build).
Summary of Contents for 605 Series
Page 16: ...1 4 Getting Started 605 Series Frequency Inverter ...
Page 22: ...2 6 An Overview of the Inverter 605 Series Frequency Inverter ...
Page 34: ...3 12 Installing the Inverter 605 Series Frequency Inverter ...
Page 48: ...4 14 Operating the Inverter 605 Series Frequency Inverter ...
Page 156: ...8 2 Routine Maintenance and Repair 605 Series Frequency Inverter ...
Page 198: ...12 12 Certification for the Inverter 605 Series Frequency Inverter ...
Page 202: ...13 4 Application Notes 605 Series Frequency Inverter ...
Page 204: ...14 2 Serial Communications 605 Series Frequency Inverter ...