Hardware Description; Mechanical Construction - GE Multilin DFF Instruction Manual

6. HARDWARE DESCRIPTION

The DFF incorporates electronic components that might be affected by electrostatic discharge currents
flowing through certain component terminals. The main source of electrostatic discharges is the human
body, especially under low humidity conditions with carpet floors or isolating shoes. If such conditions are
present special care should be taken while manipulating DFF´s modules and boards. Operators, before
even touching any component, must make sure that their bodies are not charged by either touching a
grounded surface or by using an antistatic grounded wrist bracelet.

6.1 MECHANICAL CONSTRUCTION

The DFF case is a standard 19" (or ½ 19'') rack, 4U high, manufactured in stainless steel and painted with black
epoxy resin. It is composed of a four-sided wrapper, which includes the modules/printed circuit guides, plus a rear
plate with all the terminal blocks.
The case has a surge ground connection terminal, essential not only in terms of safety, but also for behavior against
electromagnetic interference.
All the modules can be withdrawn, enabling easy maintenance and repair.
The DFF has a polycarbonate front cover. This keeps the relay sealed, providing protection against dust and water
(IP51 index according IEC 529). The use of a push-button allows access to the main functions without the need for
removing the cover.
The front and rear views of both versions of DFF are shown on list of figures at the end of the manual.
DC power and AC electrical connections are made through 12-way terminal blocks located at the rear of the case.
The DFF includes up to three communication ports. One in the front for local connection and the others located on
the rear plate, used for remote connection.
The internal architecture of the DFF is composed of the following drawout modules:
•
Power supply module.
•
Magnetic module (AC voltage inputs).
•
Protection CPU module.
•
Communications CPU module.
•
Up to 3 Modules for the digital Inputs and Outputs. (see ordering code/model list for options)
Each of these modules has a DIN type front connector for the connection to the internal communication bus.
GEK-106166E
HARDWARE DESCRIPTION
DFF Digital Feeder Relay
6.1.1 CASE CONSTRUCTION.
6.1.2 ELECTRICAL CONNECTIONS.
6.1.3 INTERNAL CONSTRUCTION.
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