ABB ACS 502 Series, Installation & Start-Up Manual

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Chapter 3 – ACS 502 Installation Instructions
3-8 ACS 502 Installation & Start-up Manual
Dynamic Braking
When Dynamic Braking is required, connection is made to the DC bus
terminals. Dynamic Braking can be accomplished in two ways.
1. Internal Dynamic Brake Chopper. If the ACS 502 was provided from the
factory with dynamic braking, the control logic and power switch for the
dynamic braking are built into the drive. The DC bus voltage is present at
the DC bus terminals only when the DC bus voltage exceeds the braking
threshold due to regeneration.
To determine if the internal dynamic braking chopper has been supplied,
first check the part number as described in Chapter 2 – Overview of the
ACS 502/504. If the internal dynamic braking chopper is supplied, an
external resistor load bank is connected to the Brake terminal (BR) and
positive DC bus terminal (UDC+).
WARNING! Before connecting a resistor load bank to the DC bus terminals,
measure the voltage at the terminals with power applied to the ACS 502. Use
a meter rated greater than 1000 VDC. The voltage should be zero volts. If the
voltage is 1.35 x V
IN
, the internal braking chopper is not present, DO NOT
CONNECT LOAD BANK RESISTORS.
2. External Dynamic Braking Device. If the internal dynamic brake
chopper was not supplied and dynamic braking is required for the
application, an external dynamic braking chopper and resistor load bank
can be connected to the DC bus terminals.
WARNING! The brake control terminals carry a dangerous DC voltage
(1.35 x V
IN
). No device other than an ABB Drives dynamic braking device
may be connected to the positive and negative terminals of Terminal Block
X2.
Control Connections
Available Control
Locations
The ACS 502 can be controlled from the Keypad located on the front of the
enclosure or with an external control device.
External control devices, for example a PLC or remote operator devices, can
be connected to Terminal Block TB1. These control devices can be Analog or
Digital. Refer to Terminal Block Connections in this chapter.
When planning control wiring from ACS 502 and external control devices
consider the following:
1. All external control wiring to TB1:1 to TB1:20 must be done with
shielded cable and must not be run in the same conduit or raceway with
any high power wiring. The shield connection must be terminated at the
chassis ground lug provided. The other end of the shield should be cut
and taped back at the signal source.